Jeroen Leenarts, podcaster, self published author and CocoaHeadsNL chairman

Jeroen Leenarts: Welcome to Episode 101 of my podcast. This is an encore presentation of the interview that came our net debt with me for my podcast. Currently, I'm enjoying some time off. So I'm doing a couple of these encore presentations, because these are some of the episodes that I really liked over the past almost 200 episodes. So and I will speak to you again in a couple of weeks time. I'm sitting here with Kim, and it's a special episode again. But this is an extra special episode, because we're doing something different today. So Kim floors yours. Kim Arnett: Hey, everybody, we are swapping the script, I will be your host this fine. day or evening. However, you're listening to us today. I am here with your own liner. Jeroen Leenarts: Pretty good, I think yeah. Yeah, that's names. It's horrible. Kim Arnett: You try again? Jeroen Leenarts: No, no, it's fine. Okay, Kim Arnett: so I'm very curious how you got your start with computers and software engineering, Jeroen Leenarts: it's a pretty long story, actually, when I was a kid, my father brought in Sid expectrum, into the home. So that's a Sinclair computer. And you could only program that with basic and you would like type programs from magazines. But also in the middle of the night, there were these broadcasts on the radio that were like programs being broadcast over radio waves. So if you know the old style computers yet, with tape acts and stuff like that, you can actually record that from the radio, played it back into your computer, and you will also have a program pretty much played a lot of Manic Miner on it. And yeah, I always make mistakes when copying the code. Because I was like, I don't know, eight or nine years old and, and didn't really get into computers back then. But it was a start. When I was like a little bit older, I think it was 12 or 13, my father bought Intel 286 base computer. So we skipped the whole XD phase of computers. And we were able to play. I think it was Wolfenstein 3d and Commander Keen and those kinds of computer games on that that piqued an interest. That was all going quite well. But at some point, this computer was aging. And we needed to do all sorts of crazy stuff with boot discs to be able to keep on playing games. So that's when I really got started into like loading drivers into high memory and all kinds of more intricate stuff that you will do with the command prompt. So then I just kept on playing computer games, and basically all the money that I earned at some point with all kinds of small odd jobs that was put into video games. So at some point, I had stacks and stacks of these big boxes with CD ROMs in them. Because after 286 486 came along, and then at some point, some Pentium based computer. But that was that was my time with computers really. And then at some point, I had to basically choose what my primary education would be, like, you know, like at the at the university, high school level. And I was like, Oh, I like video games. Maybe I should do something with computers. Apparently you can earn a living with something with computers. So I got into basically a software development program at a local university. And that's pretty much where we got started with software development. So it was a typical Java based program that you had back there. Yeah, basically, that's just it. My first programming through my education really? Kim Arnett: Wow, that's really great. And I had no idea that there were ever programs and magazine. Jeroen Leenarts: Oh, fascinating. Yeah, it's it's shows my age a little bit, I guess. Kim Arnett: So it sounds like you were kind of destined to go into this field from the beginning, some from such a young age. Is there ever a moment that you ever envisioned yourself doing anything else? Jeroen Leenarts: Well, I right before I got into my education there, I tried applying for the touch military for fighter pilots on an F 16. I failed miserably. And I think I got kicked out at like the second round. So that's like the first day that they have you show up it's like yeah, for your interview, then some psychology assessment and then some tests, and then it was gone again. So that that was that dream, shattered and thrown into the wind. And I definitely didn't want to do anything that was like ground based. So yeah, that's something that I pursued like a little bit, like more like a childhood kind of dream but Yeah, after that it was pretty much software development all the way. And I started my education in 1998. graduated in 2002. And I've been programming in a professional fashion ever since. Very nice. Glad to hear it worked out for you. Yeah, desperate things that you can do to make a living, I guess. Kim Arnett: Absolutely. So how did you end up in iOS? What was it about iOS that really piqued your interest? Jeroen Leenarts: That's interesting, really, because I initially worked for close to nine years, at my first employer, because I graduated with an internship. Once that's all completed, you have your diploma, often, they also offer you a contract to come work with the company that you did your internship. So I stuck around there for nine years, it was a consulting company. So I was basically a software developer for hire through a company. So I've seen a lot of companies there from the inside. But all things I did there were Java based. And then after like, eight years, I got an interest in Apple computers through the iPad, I think it was had like this, not original iPad, but like a smaller model that came after that. And yeah, that piques your interest. And back then it was very normal to also develop Java on Apple hardware. So there was a proper support for Java on the on the Apple Mac. So I bought myself and I think it was a MacBook Pro back then there was like in the, in the leopard Tiger, really. So that's 10.3 and 10.4, I think. And once I did that, I enjoyed working on that machine. And then at some point, the iPhone became a thing you know, yet the original iPhone that you JavaScript is good enough for everything. And then at some point with iOS three, you could actually develop software for it. So they opened up the SDK a lot. And then once iOS four came about, and I really got interested, and started pushing within my then employer to actually get me jobs with iOS. Because I also bought an iPhone for myself and was playing around with some, it was before Xcode. So it was with interface builder, and I think it was called Project builder. But I wanted to work with those tools. There was some opportunities there that didn't work out. So then I applied for another job at another company. And I ended up working there at the Dutch ING Bank on their banking application. So basically learned iOS development on the job there, at least learn it properly. So yeah, why did it get interested in iOS development, that's basically the idea, you have like this small device, especially the phones back then they were really small. The responsiveness was this quick and the scrolling, because when you had like your first iPhone, you were literally just sitting around and playing with any app, really, and just play with the scrolling and see how the bouncing work. And it was just like a sort of a fidgeting toy, I really wanted to be on that platform and create products that would also be on this tiny screen. But I wanted to work on products that were that intimate to end users so that it was something that you had in your pocket with you all the time. And that's basically why I got started with iOS development. Kim Arnett: Wow, that's really exciting to be at the forefront of iOS and really be with it from the beginning. Jeroen Leenarts: That it's particularly challenges because back then it was really, you had to make sure that you lined up all the pixels correctly. Otherwise, the performance hit of the system, doing all kinds of things was so big that you would be scrolling, but then everything would be jittery, and not like smooth the way that you want it. So you would actually spend hours profiling your product, it just makes sure that it was scrolling smoothly. And nowadays, that's not that big of a deal. Unless you do really weird things in your data sources for your collection view or your table. If you already you had to do things that you wouldn't even have to consider nowadays anymore. It's just it's okay to just burn a few CPU cycles. So nowadays, batteries are big enough, and it'll just work and no issues there. So but we actually would get complaints by end users that the app was not scrolling smooth enough for something. Kim Arnett: So how do you feel about the path that Apple and iOS has taken over the years since you've kind of been with them since the beginning and where they're at now? Jeroen Leenarts: Oh, that's a good one. Well, one of the reasons that I grew an interest in the Apple platform is that it's a it's a Unix flavored system. So you have like the BSD subsystem, and of course then the apple kernel and everything is like aplly but every Seeing the tooling and the command line and a lot of stuff on top of that is really based on BSD type systems. So that's that, that implies a lot of openness really. And it's a contradiction. If you're like an Apple fan, in that way, because it is a Unix type system is in on one end, you really liked the openness of the system. But on the other hand, you also like the conciseness of the entire system, so that it's, it's a packaged product. And, to some extent, you know, that's everything that is supplied by Apple should work together in in a reasonably good fashion. So it's always been like a field of tension within the Apple ecosystem. So because on the one hand, they really want to close things down, and make sure that you can't do things that are you're not supposed to do that are bad for the end user. But on the other hand, you do want some openness. And especially if you jailbreak an iPhone, haven't done that for a while, actually. But then you really notice what it is actually that you're carrying in your pocket. Because this iPhone system, it's a full, it's a full blown complete, Unix like system. That's, that's on a small device. Yeah, and then the, the nerd in me really thinks like, I want to, like break this open, play with it, and just have fun. But on the other hand, I do understand the, the walled garden that Apple creates, so that you can do everything you like, within the constraints that Apple provides you. And I do think that constraints that are there, they have in some way also shaped the entire platform and the entire developer ecosystem. But these constraints, sometimes they really limit you. But I do think in some ways to also make developers creative in another way to achieve their goals within the constraints that are in place, and to make sure that you can create some meaningful product for your end users. But still, it is a lot of fun to just have like a Unix system and be able to play around with it. And just and just to break things really. Because that's, that's something I really enjoy doing. Every now and then, for Kim Arnett: sure. I've actually never jailbroken a phone, I am too scared. Jeroen Leenarts: out one tip, never ever do that with your primary phone. If it's the phone that you depend on to actually reach your loved ones. Your family don't jailbreak it? Because there's a lot of risk and and drawbacks really, that are in place if you jailbreak your device, because basically, you just run software on your phone that you have no clue really, who wrote it. What's the purpose of the software is if there's a hidden agenda within this code. And it's really sound advice to just have an extra phone and do weird stuff with that phone and just keep an everything from your real Apple account away from the single phone. Really? Kim Arnett: That's really great advice. Absolutely. I actually learned that with a beta OS, which should have been pretty safe. But then I could only answer my phone on speakerphone. Jeroen Leenarts: somewhat annoying, if you're like in the subway or somewhere that you're like, somewhat not able to speak in private? Yeah, it's one of those things, because nowadays, I don't do it anymore. But it used to be that you were like really like looking at like to the better releases of iOS just isn't good enough. Should I install it? And maybe not maybe no. And it was like there was this advice going around on the internet lecture. Yeah, just wait for like the third or the fourth or whatever, number better. And then it'll be good. But we all know what happened with I think was the iOS 13 Beta cycle that was like, truly horrible. They were like, just one month before the actual release, it became somewhat stable. And then even after the real release, they still had to do some updates to iron out some some issues. Kim Arnett: Yeah, this is a little bit off topic. But do you remember when the big phones came out? And they were bending in people's pocket? Jeroen Leenarts: Yeah, yeah. And then the advice was you shouldn't sit down with your phone in your pocket. Yeah, Kim Arnett: lots of good advice here. Don't don't install beta on your phone, don't jailbreak your primary phone. Don't sit on your phone, maybe wait a little bit before buying a new phone. So I want to shift a little bit and go into your career a little bit more. What are some unique challenges you've conquered in your career? Jeroen Leenarts: That's like a broad question. Let me think about that a little bit. Kim Arnett: Basically, what what makes your career a little A bit different than everybody else's is kind of what I'm getting at. Jeroen Leenarts: Yeah, well, I think one of the strange things that I did was sticking around for nine years at my first employer, of course, I've seen a lot of different companies there. But what you tend to hear is that people at the first employer, they, they stick around, like maybe two years, but usually within five years, people move on to the next place. In hindsight, I would say, maybe I stuck around there a little bit too long. I just didn't know any better. Really, what I did after that is I worked for four more years at another consulting company. So I've been close to 14 years, I've been somewhat of a contracted developer. So it was always flown into companies as like, this is the expert on topic. Something while sometimes I just was not any experts on the topic at all, it was just at some point I was available, I was on the bench, so to speak. And I read something about some framework or some tool or whatever. And but you were sold like one of the experts. So I did, I did a lot of like, learning on the job and, and running in front of fellow developers and basically being Mrs. Doubtfire and keeping up appearances. And it works out fine. Until I really got involved with my now wife, and kids got involved and everything. So family life, because that takes a lot of time and energy as well. And it also brings a lot of fun, of course. But what I did notice that at the moment that family life became really a thing. My wife and I, we really sat down and we constantly made the switch, okay, I'm going to work closer to home, I'm not going to be like working for like, more than 40 hours each weekend and those kinds of things. So that was really hard for me. In the beginning of my career, I really was somewhat of a workaholic, just keep on edits, and just program away and just just for the fun of it, really. And yeah, what is unique about my career in that regards, as that, on any topic that I worked on, I was able to really go to go to go deep on those things by just reading things, trying, basically something that, that Alan also said, in a recent interview I had with him and at this Learn, try and then apply. Basically just you you learn topic, you experiment, just the minimum that you need to do to make sure that you know something about it, and then just do it. Because that that's practice in practice is always the best way to learn. It also involves some risk, but I've always been able to take take risks with codebase in that sense. And, yeah, I wouldn't like consider my career in any way unique. But what I did do is I always liked sharing information with people, you know, I just have always been doing presentations, like in the company, sometimes at smaller conferences, and at some point that ended up in me becoming a part of the Dutch cocoa hats. And I've been doing that for close to eight years now. And yeah, it's besides really the decoding it's one of the biggest things that I enjoy doing just facilitating other people to to to step out of their comfort zone to start presenting to an audience to give them feedback on things they did and advice that I can give based on my experience and things I learned from other people. That's something I really enjoyed doing I think Kim Arnett: so. You mentioned having a lot of Mrs. Doubtfire moments and context switching and, and being the expert of your field. I'm curious to know how did you keep your imposter syndrome in check? Or if you did feel impostor syndrome during that time how you managed it well, Jeroen Leenarts: it's it's it's what I like to call the Dutch approach. Just I think there's a there's an English proverb that is damned the cannons full steam ahead. Just just do it dive in. Basically, hey, there's a nice pool here. That's that's like the baby puddle and there's the deep end. Let's go for the deep end. That's always what I tended to do. Because I have this. Of course, I've had my doubts, I've had moments that I was like, Is this a good idea, but I've always been able to, if I make a choice, then then I can really, that it can really execute on it. Sometimes to my, my own, to my own destruction, really, because sometimes it ended up with me doing like late nighters and making things right again, after like, causing some issues. But I really have been able to, to, once I make a decision, and I've thought about any doubts that I might have to just consider those doubts, so that I address them, and then just make me make up my mind and then deal with the consequences. Because in the moment that I made my decision, that's when I can doubt a certain things. And unless there are other circumstances or other effects that have that have to change that make that make me change my decision. I don't doubt my decisions. And it's I think it's something that's it comes from me being like really stubborn. Which was like a really a giant pitfall when I was a teenager. But fortunately, at some point, I was able to, like turn this pitfall into somewhat of a strength. It does have a tendency that if I have made up my mind, and I can like be like this. I can be I still remain very friendly, but it can be somewhat of a steamroller. And, yeah, that's how I deal with that. And then I suffer the consequences if it doesn't work out too good. But I've always been able to explain myself and why it was not that buildings were like burning down. It's just that maybe we need to refactor some code. We'll manage it Sure. Cost has always been within like the the five digits sure that I've incurred by my choices. Kim Arnett: One. One quote that always comes up in my mind around that is I need to know when the toaster is on fire, not when the house is burnt down. Jeroen Leenarts: Yeah, yeah, that's always good to know in detail, that sometimes you make decisions. And it's like, you're like five steps in and you immediately know that you made a bad choice. And it's what's really interesting to see with companies as well, is what they call the sunk cost fallacy. Because for some reason, people and companies, if they've made a bad decision, they keep with the bad decision, because they already invested time, energy money to some level, and then in their minds, they will lose the entire investment of these resources. And then they keep on adding more resources to actually try and get a better result. While at that moment, at the moment that you can reevaluate your choice, the best thing, sometimes you can just do is cut your losses and try something different. And that's, that's really interesting to see how a mind can actually fool itself into doing something that was stupid and do something that is even more stupid with the same idea. Kim Arnett: Yeah, certainly. So small pivot. Again, we're staying within your career. But I'm curious to know what were the events that led to you launching your own podcast? Jeroen Leenarts: Well, if you would say directly, it would have been, you could say it's the COVID thing that's been going on for over a year now. But yeah, that costs every sub but yeah, let's let's rewind. So like March 2020, COVID, hit like in the Netherlands. So everything was starting to lock down worldwide, including the Netherlands. So the coca has meetup community that I was running, we had to move online or stop what we were doing because the format that we had was meetup in person at a company that was sponsoring their venue and some food and drinks. Of course, there was a bit of a problem with these new restrictions in place. So we moved online. And what we always did is that if you had like a lapse in speakers, so that if you had like a scheduling hole, one of the four of us would actually say, Okay, I've got something on the shelf or I have a concept that I can easily convert it to a presentation and I will do that. So in I think it was I think it was September, maybe October 2020 Do we had one of these situations? And I stepped in and I said, Okay, I'll do a presentation. But for me that was the first time doing a presentation, pre recorded. And then yeah, played online. So because what we tend to do is pre record a presentation, played back through a live stream, and then have the speaker available for questions afterwards. So the q&a is, it's impersonal life. So I was, I was recording myself, it was completely uncomfortable, you just sitting in front of a computer and no audience speaking into a microphone and just really feeling bad about myself while doing it. Fortunately, the end result was somewhat okay. And it's, it's a talk that is still available online. It's talk in which I talk about jewish.io, which is like a tool that allows you to generate Xcode projects, so that you don't have to commit your Xcode projects into Git, and you don't have any merge conflicts on your, on your Xcode projects, because that takes away like 80 or 90% of your merge conflicts on an iOS codebase. And you express your project structure in Swift, so hey, it's all Swift. It's the best you can have. Right? So I did that presentation. And then afterwards, the event was over. And yeah, it was somewhat okay. I was not okay, because I was like really feeling bad about myself. Like, I don't enjoy talking into a microphone without an audience. So what's the best way to do that more? Well, you can start a podcast because the thing that you're doing there is talking into microphone and recording yourself and then just throwing it out into the world. And that's basically the the reason that I started the podcast always was something that I was interested in, because I listen to a lot of podcasts. And then in that moment, it was like the, the trigger event that enabled me to actually do it. And that was, I think it was, it was October that the first episode was live in 2020. So that's pretty much the reason. So it said it's the Dutch approach, you could say, Kim Arnett: a prime example, indeed, you mentioned that you felt well, while you were recording it is that because there wasn't any feedback that you were given directly, like, while you were recording it from the audience? Jeroen Leenarts: Yeah, but what I want to notice with people doing presentations, there's, there's two big groups of people and of course, there's some things in between, but you have two people that really prepare almost every sentence that they're gonna say during the presentation. And you have to group of people that make sure that they know the concepts, and then just create a slide deck, and then make sure that you have to intro Okay, and maybe the outro. But anything in between it's, yeah, it's, it's pretty much on the spot. And that that's the way that I do presentations, I make sure I know topic, create good slides, so that I have some bearing on what I want to talk about. And basically, then just wing it, because it gives me flexibility when you're in front of an audience, because you can see what works, what, what, what triggers a response with people, if there's room to add, like maybe a small joke, or maybe you should take out something. And that's how I do my presentations. But if you're pre recording yourself, there's nobody in front of you, who you can look at and who you can, then basically by looking at them, ask for feedback, because the one thing as a, as a presenter that you have to learn is to be able to look into the crowd and look at individual audience members to really gain if your story if your topic, if your presentation is, is landing with them, you can just be you can just see it in the eyes of somebody who's listening. And that's, that's not available if you pre record. So that's also the biggest struggle that I was dealing with at that moment. Because I get a lot of energy out of the attention that people in a room are giving you. And I don't know what it is, but it's something that gives energy to me when presenting. Kim Arnett: Yeah, that makes total sense. And it probably really played out while you were watching it play back to you. Right? Because you're not seeing anybody Jeroen Leenarts: that was horrible. Kim Arnett: Seeing anyone's faces, you know, not many people share their video anymore. Jeroen Leenarts: Yeah, and I really needed with that presentation. I really needed like the feedback from people afterwards. Just really listened to that and hear that and just get confirmation of people. That it was okay and that I did okay, and that was a good presentation in the end. And you could say I had like, I had a case of impostor syndrome, like at that moment in time. So yeah, even I'm My like, even I can like I'm like vulnerable to it. Kim Arnett: Yeah, yeah, I totally hear that. I still get nervous. Anytime I give a presentation. I used to put some Taylor Swift gifts. Because swift in my presentation and those did not land while one. And now I'm just like, really? You know what? I totally hear you. Jeroen Leenarts: Yeah. And if you are doing like an in person presentation, you can like you can always throw out stickers. You know? It's like that to me online. Yeah, Qaeda code. That's, that's like stickers. Yeah. Yeah. Kim Arnett: If I ever give another live talk, my sticker game is going to be lit. I couldn't tell you that. Jeroen Leenarts: Yeah, you're gonna have like, the most dope stickers ever. Kim Arnett: Yeah. And then I'll get people coming. Just taking the center isn't running away? Oh, Taylor Swift gifts. Jeroen Leenarts: Yeah, that's, that would be awesome. Just like they have to stamp it like at the stage. And then like, you're like, standing there like completely, like, trampled and then all your stickers. Kim Arnett: Yeah, I might just have to hide them till I'm done. Have to force people. Jeroen Leenarts: Or maybe just hanging out the sticker every time? Somebody asks a good question, you know, from because if you ever noticed that if you have a presentation, there's always in every crowd, there's always one or two people that they ask a question, but they basically ask a question to just hear themselves talk. Yeah, Kim Arnett: yeah, I've, I've gotten that I've gotten where I gave a talk with iOS in the title. And I had JavaScript people come and ask a bunch of questions of how that would relate to JavaScript. And I just felt so bad because I was like, you basically just wasted an hour in my talk. And I have no idea how to answer your question. Jeroen Leenarts: Yeah, maybe go to the next. Yeah, Kim Arnett: yeah. I've see that was a hard one. But yeah, certainly. And, yeah. So some advice for our listeners is what I'm getting is if you enjoy a conference talk, whether it's recorded or live, please let the person know. Feedback is Jeroen Leenarts: feedback. Yes. That's, that's the best gift you can give to presentation to the to a presenter really? Yeah, absolutely. And even if even if there's something that you think the presenter could have done better, or you have an opinion on, just be respectful and just share it. Because it's, it's the best thing you can get knowing if you're doing something wrong, or if you can do something better, even with just a small adjustment. Kim Arnett: Yeah, constructive key word criticism is very beneficial. Jeroen Leenarts: Oh, I love constructive criticism. That's the best thing. Kim Arnett: Yes. Yes. Yes. So you've mentioned you know, running, is it Dutch cocoa hats. Jeroen Leenarts: Yeah, it's in in Boston, we call it the Dutch cocoa hats. Online, it's just cocoa had stopped. And now it's, it's an English language community, because in it, we're mostly focused on the Netherlands, Amsterdam area. And there's a big expat community out there. Who's not able to meet in person, but because there are so many international people coming to our meetups, we always have English as our as our main language, really. And we've started live streaming the events like I think it was 2018 or 2019. And it set us up completely ready to go for an online only format due to world circumstances. So yeah, just come and join us every month, we have a meetup. It may be a bit of a crazy hour if you're in a different time zone. But hey, Kim Arnett: nice. So it sounds like you've it sounds like it's really nice transition into the online world with how you set it up to begin with, are you and your team? What's a positive and a negative to running in person meet up? Or maybe a challenge? Jeroen Leenarts: Well, it's basically the big difference between online and offline. Because the advantage of being offline is that you get to speak to people in person so you can look people in the face and you can mingle in a room and just enjoy each other's company. Because that's the biggest thing that most people are, are missing right now. The disadvantage is, of course, the reach that you have, because it's only like the local group of people. And it has a benefit. You always see the same faces, but there's also some new faces every month. But if you're online, yeah, of course, the your audience can be all over the world. and sometimes we have meetups with like, over 200 people, and online as well. But offline, being in such a big group, like really conference size, so to speak. Yeah, the, the disadvantage, then is that you lose the intimacy that you have with a smaller group of people. Because if you have like 50, maybe 100 people in an event, and then there's a good chance that the people that are interesting to you that you have the opportunity to actually speak with those people in, in, in a natural way so that you don't force yourself upon somebody to talk with you. But just yeah, just at at a buffet or just grabbing a drink, you have an opportunity to talk with everybody who's there. And I think that's the big advantage of in person, meetups. And yeah, the disadvantages, of course, what I already mentioned, that you have a way smaller reach as an organization, really, Kim Arnett: do you think after COVID It will ever return to in person, or have you kind of fully embraced this online life. Jeroen Leenarts: While we were live streaming already, and I think we'll go back to in person for sure. But I don't know, if we will go back for in person each month, maybe we'll just like switched up like every month, because I do notice that I live quite far from Amsterdam. So at least far for Dutch standards. So getting to the event, it takes some planning and driving and stuff, and not having to get out of my house to just like, do an event of like now, like, an hour, an hour and a half. It's somewhat beneficial. So we already talked about it. And it also really depends a bit on how work culture has been affected by this whole thing. Because you hear a lot of companies talking about hybrid approaches, you know, just that the office is going to be like a meeting hub and nothing else. Maybe just work there like occasionally. We'll just have to see. But most likely, we'll do both just in person. And online, just and then just switch it up every now and then. Kim Arnett: Very nice. I'm always curious about people's plans after all this is over. Because you're right. It seems companies are all over the place. Jeroen Leenarts: That's taking so long. Yeah. Because I still remember that in back in March. It was like, yeah, like the summer everything will be normal. And then summer came and summer was gone. Yeah, by the end of the year, it will be normal. And then Winter came winter was gone. And now we're a year in Yeah. Yeah, it's, Kim Arnett: it's all too much. So one more question around your career. And we'll move on to some more personal things. Who were some people that had positive influences on you in your dev journey? Jeroen Leenarts: That's, let's see. What during my education, there was, there was like a teacher called Mr. Nauta. And what's interesting about that, like I had, for some reason, the education that I chose, they only had like a program for the first two years. And then the third and fourth year, there was no program. And we went to the exam committee and raised our concerns and our complaints. And then, with us, a group of six students, we were assigned one single, dedicated teacher for those entire two years. So the seven of us, so that's the six, including the teacher, we were able to basically come up with our own program and just execute. And the flexibility and the the support that he gave was like really instrumental in the 60s. Yeah, really developing ourselves as software developers, and being able to end up with a with a diploma that was actually meaningful, and that we had the idea that we actually learned something from our education. Also, the there was a Peter Hendricks, that someone who was like I work with him on my on my final internship, the two of us developed software together and he was from a different school, but we work together. We were like, we agreed to work together. And it was a really beneficial relationship. And I learned a lot from him, and he learned a lot from me. But we split ways. And then let's see, yeah, that's somebody that's also very interesting is Andrew snare. When I came into the iOS role at the ING, I was basically sold to the pro I checked in a way like, Yeah, this is urine. Don't worry, he'll manage. He does not know much about iOS development, but we'll be able to vouch for him, he'll do fine. And oh, and the first two weeks, you get him for free. And then they linked me to Andrew snare, who's an Australian and to was doing iOS development at that same project from the same company that was that we both were working for we was contracted out to the IMG. And he basically learned a lot of things about iOS to me. And we work together very well, very intensively for like a month. And then that that cooperation was lessened because he was able to see that I would be able to manage, but he still was available for any questions and support and just being like, what a proper senior developers should be for a junior immediate developer in its vicinity. And then, let's see, yeah, there's a company after that I worked for what's his name Erevan. And that's, that's especially interesting, because I worked on an iPad product for like a year and three months as a as an in between job. And what was interesting there is that we developed the front end, but also the back end. So there was like a Django REST based back end on Amazon AWS services. And it was for developers and the four of us, we basically did everything was like a startup type company. And he, he looked at my resume and saw, okay, he did a lot of Java on the server and on front end everything. He knows iOS development, yeah, he'll manage with like Django, Python, and it takes some effort, but he trusted me to be able to learn and just be able to be dangerous with with PI charm was the IDE that we're using. And he also like really showed to me what, what a senior developer should be for a project and its surroundings and the business really. And I think those were the two biggest influencers in the in a positive way in my career. Kim Arnett: Yeah, that sounds really great. Really great to have that support. Very important. So let's pivot again. And so a little bit more personal. So you just launched a book? Yep. Lead developer? Did you get a lot of your influence from your own personal journey? Or, you know, from some of the people that you just mentioned, and their help to you? Where Where did that advice and inspiration come from? Jeroen Leenarts: Well, basically, just for the heck of it, I read a book by Karmiel. I don't know her I don't know her last name at the moment. Karmiel. For fun, yay, I think it is. And she wrote a book, it's a blue cover, it's called the managers path. And it's, it's a book that is about if you work in a tech role, just from like software development, all the way to CTO and all the tech roles that are in between those, those levels in the company, really. And it was a very interesting read, because it basically gives you an insight in what a potential career ladder could be for somebody who starts in tech. And of course, you can choose your level on the career ladder. However you see yourself whatever suits best to you. And, but what what is a drawback of this book, because it is such a big arc on all the content that is covered is that it doesn't go in depth, too much on specific details. And a little under three years ago, I started at my current company, that's a big insurance company in the Netherlands. And what was happening there was that the I was like, the most senior developer that was hired on the iOS team, and basically needed a lead role to be filled. And they basically said, Yeah, well, you're the highest paid engineer. So you're going to be the lead developer. I was like, Okay. And now what and I basically had to learn on the job. And of course, I had really good templates to my experience from my own history with other people. So I, I had some idea of what I think would be a good lead developer. So just over the last two and a half years, I've made a lot of notes on things that I think that work for my teams and things that I think would really be beneficial if you are like providing the leadership role within a team. And at some point, I wanted to like really compile those notes in some way into like, really practical things that you can do as a lead developer. So that it basically was a way for me to structure all those notes into something that I would like, if somebody would ask me a question. I could basically say, yeah, hey, just read this. And then if you have any questions, then come back to me. And that's pretty, that's pretty much the the reason that I wrote this book, it was really like, trying to write a book that I wish I had, like, maybe like, two years ago, so that I had an easier time back then. And then in the end, it really resulted in me like, being able to reflect on my own experience, and just write down and compile practices and things that I actually do day to day. And sometimes I wish it would do more. So yeah, that I have like, really like my own menu of things. I should not forget when doing my day to day job. Kim Arnett: Yeah, certainly, I feel that I feel that. What is your wife's name? Jeroen Leenarts: Her name is Carmen. And we've been married? Like, I don't know, seven years now. I think, yeah, pretty much. She'll kill me if I'm like, like, one year off now. Kim Arnett: Yeah, you're heavily invested. Now you better get that right. Jeroen Leenarts: I can always cut it. Kim Arnett: Okay, so you, you mentioned when we were talking online, that your wife, Karen is a school teacher. And I was wondering if you think having her as a resource or having some insight into her career, and her job helps you create content in a more digestible way? Jeroen Leenarts: I think so she doesn't read the things that are right, because she always says like, Yeah, but it's like technical, and it's way different than what I do. But we do talk occasionally about like, what it's called the, what is a good structure of, of course, material, what is good structure in a book. And also, because we have two children of our own, you do see a lot of the things that she applies in her professional life, and that she applies those for in a very practical way in our family life as well. So I actually learned a lot from her in how to really behave and deal with the troubles that my two kids can actually cause. Because they can be a handful sometimes. And I think that indirectly, she had a lot of influence in ways that I structure content. Also, at previous jobs, there was somewhat of an investment made in, in my abilities to at least create presentations. And of course, that's also structured content. And I think part of that stuck with me, and but her role as like, being like a trained professional. At the role of teaching things. I think that's really helpful because I do occasionally ask her, Hey, is this a good structure? Or what do you think? Should I first do the concept in kind of an abstract way that they explain it to her and so that it's at a level that she can really relate to it? But that yeah, sometimes she does give input. In those cases. Kim Arnett: That's really great. If you if you ever partner up and create a book on managing a household, let me know. Give us some tips. Jeroen Leenarts: Yeah, I probably can use it to myself as well, because I always say that, that my wife manages my work life balance. Yeah, it's a lot, which basically involves she telling me what I need to do in that. Kim Arnett: Sure. And especially in this time, it's just, it's crazy. We have two kids myself, and they're both in school for the most part, but sometimes, you know, things happen. They have to stay home and it's just total chaos. Jeroen Leenarts: Yeah, I've got a three year old and a five year old. So the three year old Milan, that's a boy is he's not going to school yet. That's like in about a year's time he is then he's allowed to go. He already he can't wait to go because his big sister is already going every day of the week. And Big Sister Lisa, she's five. And she skipped one of the classes in in her school already. So she in the Netherlands have like eight groups in primary school and you enter at like four and a half five ish at group one. And then group two. So that's really like kindergarten level. And then in group three They really start with the structure training of language writing, and really the basic skills that you need to be able to start learning. So she basically skipped her group two. And still she's struggling right now. And then with, like, just being a little bit different, you know, and. And she's really like a handful if she's not able to get the energy out. But it's fun, sometimes just having this this frustrated ball of energy bouncing around in the living room, shouting and saying what she wants, what she doesn't want and stuff like that. Kim Arnett: Yeah. So how do you manage, you know, having kids and house and house projects? You've mentioned in previous podcasts as well, and work and writing books and podcasts and running a user group and family time? How do you, how do you handle all that? Jeroen Leenarts: Basically, not having to travel a lot for work really helps, because that saves like, a couple of hours each day. And at my job, there, I have a contract for 36 hours each week. So that's like what I consider full time. And the work for the meetup community is not that bad. That's like, once a month, it's like really one and a half hour of clock time. And in between, it's really like the occasional like sending some emails, replying to some sponsor queries. So that's, that's not too bad. The book writing really was like, sort of like an, an outlet for me to be able to, like, put all this stuff out of my brain, because I was thinking about this stuff so much, just being able to write it down, which allowed me to actually relax about it a bit more. And then podcasting, you could say that's like, it's a bit of a hobby that that went out of hand, because I'm doing it for six months now. And I'm already past episode 50. And at least half of those episodes has been an interview. And especially the just creating a podcast episode have like 50 minutes, take like one one and a half hour, and the interview episodes, that takes like an hour recording, and then the editing. So that's basically two or three hours additionally, to actually make sure that it's okay, so that it's like presentable. Or even though it's audio. Yeah, and it's just, it's, it's all just like fit in between, because my wife is as some hobbies that are in the evenings as well. Of course, she can't do that too much right now. But it used to be that those were the hours that I was doing stuff that was not work related, that was not family related, but was somewhere in between, you know, so the stuff that I just enjoyed doing. And basically, the only thing I tend to do, besides my day job is is things that I enjoy doing. And that really helps as well. Of course, it takes effort, it takes energy, but there's also some, some gratification that you get from doing something you enjoy, even though it might take some energy. So yeah, it's, it's always that if if something is is like a hobby, then it's okay. If it's it cost some effort, if it costs some energy, and then it's not, it's not too taxing on your let's see, yeah, then it's not too taxing on your well being so to speak. Kim Arnett: Yeah, I like that advice. So we are getting pretty close to time. I do have a question from Twitter. The question is, how would you handle problematic people who hold the majority of knowledge that the team needs to succeed without pushing them too much for fear that they would leave. Jeroen Leenarts: But I've never been in the position that I was the person that was not on the knowledge Island. Because what I noticed that for some reason, I tend to be the person on the on the knowledge Island really. And I don't like that situation. Because what I've seen in practice in at a company that I worked was that at some point somebody was getting on the knowledge islands. And what they basically did was they gave this person was an external consultant. What they basically did with this person is told him, okay, either you're going to share this knowledge, or we're just gonna cut you from the project. And then we'll just manage because it's very interesting because a lot of companies they have fear for knowledge islands. Because yeah, there's one person if they leave, you have an issue. But that is indeed true. But you have to make sure as a company that you prevent getting yourself into that situation. So if you have somebody that's at such a high level on the on the knowledge Island, you did something wrong already, of course, how to deal with it. In that situation. Basically, it's just taking somebody off of the other islands and just first initially friendly, request them to share their knowledge, if that doesn't work paired up with, with senior engineers that are able to understand what's happening. And yeah, in worst case, you have to reverse engineer what they've created. But that takes a lot of effort already. And then the ultimate measure that you can take is just, yeah, re architect that part of your code. But that's like, that can be a really big challenge. So yeah, the risk and the cost of being basically held hostage by one of your employees. It's, it's, it's something you never want to have as a as a company. So yeah, fortunately, I've never really had to deal with the issue is to such a level that it was that it was really a risk for the product or a project or maybe even the company. And I always try in practice, just to prevent it. Because I always noticed that as a team, you get way further and you're way better. If there's like an open, basically a community on the product that's like sharing and helping each other and basically picking up if somebody drops the ball on something. And, yeah, I really hope and I try to instill such behavior in on any situation that I'm working on. But it's really hard, because it's so easy to end up on a knowledge Island if you're like working on a specific topic. And you're working ahead, so to speak. Because right now, at the current project that I work, we're using Azure DevOps as a build pipeline, and everything is built automatically. But what I do notice is that there's not a lot of people that are familiar with the Xcode build command. And yet, we basically chose to use like command line level stuff without using Fastlane tools, for example, because we wanted to use Apple provided tooling as much as possible, because then the learning curve is a lot lower for people coming in. And already helped us in a few occasions, because even though I had like the knowledge advantage in that area, other people were able to pick up on that in part two, the documentation that was available, but also because we really tried to keep things simple. And yeah, that's also one of the things. How can you how can you tell if you're if somebody is climbing on annoys islands, that's basically if somebody within the team create something and the most junior developer on the team is unable to understand what's going on with this code, then alarm bells should be going off, because basically, anything that's created within the team, everybody within the team should be, within reason, be able to understand what's going on within these bits of code. Kim Arnett: Yeah, I think that's really great advice. And I also like the term knowledge Island, I've not heard that one before. Jeroen Leenarts: Yeah, but an island, you can do two things. If there's an invader, you can either kick them off, and keep the island to yourself, or welcomed him with open arms and share the bounties of the wonderful tropical paradise that you're on at that point in time. Kim Arnett: Yeah, that has worked really well. I dig it. So I have one more question. But it's up to you. If you want to answer it. I know it's kind of long. What is some advice you wish you could give your younger self or somebody coming up as a junior in the app space now? Jeroen Leenarts: Well, if you're like coming up in the app space, specifically on iOS, don't focus all your attention on Swift UI only. Because right now swift UI is not ready for primetime yet. It is great. It's great tooling and it eases a lot of the learning curve. And if you want to get up to speed with Swift and swift UI quickly, just go with Paul Hudson's 100 and days programs, I just have to Swift UI both are great. And if I want to give advice to my younger self, is to be open to change more, because I stuck around with my first employer for a little bit too long. And I really enjoyed that company. And I still have good memories of that company. But in hindsight, I should have changed up my career earlier. Because the benefits that I've gotten from basically change of scenery and a different environment is so big. And those were actually the years that I have the Yeah, that basically was able because it didn't have any ties. So no family, no obligation. Assuming that no no financial burden that was too big, that I still had like the opportunities to do maybe something crazy. So, in hindsight, maybe I wish in the first 10 years of my career, I wish that maybe I would have taken a little bit more risk with the work that I was doing. So yeah, that's pretty much it. Kim Arnett: Sure, also solid advice. I dig it. All right. Well, thank you so much you're on for talking to me today. I really appreciate all the insight and advice and of course, your career and you know, how, and your path for how you landed where you're at today. It's all very interesting. So thank you for having me. My name is Kim Arnett. And I can't wait to talk to you again some other time and my own podcast. Jeroen Leenarts: Kim, thanks for your time and really enjoyed talking to you. And we'll definitely switch it around to the regular format for my podcast as well, because I'm really curious what your experience has been in your career, because from what I've read online, there's also some interesting and maybe even some crazy stuff that's happened in your path as well. So thanks for your time, and I'll talk to you later.