Donny Wals, author of Practical Combine and Core Data, iOS developer at Disney Plus

Jeroen Leenarts: Hi, and welcome to my second special edition. I've got a new guest in my podcast right now, he was challenged by my previous guest. So it's already like no surprise, who it will be, it's going to be Donnie walls. And Donnie is a curious fashion and iOS developer from the Netherlands who loves learning, sharing knowledge and programming in general, he has experienced with several technologies like Python, SQL, PHP, JavaScript, but iOS has been in his passion for a while now. If you're looking for a speaker for an event, need somebody to help you, and you can find him. You can count Danny. Hi, Danny, welcome to my podcast. Donny Wals: Hey, it's great to be here. Jeroen Leenarts: What was your thoughts? When you listen to my podcast? And you actually hurt your own name? Well, Donny Wals: you mean like 40 invites to come here? Yeah. So I figured I couldn't say no, right. I have to accept this challenge and to go in and just be a guest here. So happy to be here. Jeroen Leenarts: And was it me? Or was it Antoine? Donny Wals: That persuaded me? Yeah, that of course, was you. Jeroen Leenarts: Thank you. So. So yeah. Let's let's start at the beginning a bit. Because how did the two of us actually meet? Because we know each other for a little while now? Donny Wals: Yes. Gosh, how long would it have been? I want to say six, seven years, maybe more. Jeroen Leenarts: Now already. Donny Wals: I'm sure we met at one of the cocoa ads meetups at and we just kind of got in touch every now and then. And I still remember very distinctly is you sent me a late Slack message somewhere around 11pm. Maybe later, on November evening, that you knew that a little birdie had some information for me that I would receive more info soon. Do you remember that? Yep. And yeah, that is a fun story of I think that was around the time where we actually met each other, which was probably just a few months after we met Jeroen Leenarts: each other. So what was the little birdie trying to tell you them? Donny Wals: A little birdie was trying to tell me that I was going to speak at my first conference, which was do iOS very similar to Antoine with a really cool opportunity where so remember as well that I was nervous enough during my presentation, making slides. And you know, you have one big screen behind you normally at a conference with your slides on it. And then I got the specs for the Beamer and it said you have three screens. Good luck. So I was like, Okay, I have three screens, and what am I going to put on them? Of course, it was an option to design for one screen. But since it was my first talk, I wanted to start with a bag. So I wanted to use the three screens, which was, that was a ton of fun. That was the most fun to make a presentation for ever, actually. Jeroen Leenarts: So yeah, that was on do iOS 2016 Improving apps with iOS 10 notifications, I will make sure to link that presentation from the show notes. So this was like this is like the first public speaking engagement that Donnie did. And I was actually organizing this conference, I think for the second time. Yeah. And Antoine was the the wildcard participant the year before. But what we did do was give Tony a little bit of heads up compared to Antoine because Antoine had like 24 hours. And you had a you had a couple of weeks I think or a couple of months. And it was something that I want to do with every conference that I organize, I always want to have like this. It's a risk. But you always want to have like his wildcard you know, somebody you don't know how they will behave on the stage, but that you know, that are decent people so and just just give them a chance. Just shove them on there. And then just hope for the best. And I think you did really well. And you did a lot of things since your first presentation at do iOS, I think? Definitely yeah. Can you tell us a bit about that? Donny Wals: Yeah, sure. So that presentation. In 2016. It feels like it was much longer ago. I think I messed up the timeline when we met Actually, we met years before that conference, because it was at least six years ago we met has to be Jeroen Leenarts: Yeah, I've been I've been doing coke heads for seven years now. So it's very likely that it was Donny Wals: Yeah. Anyway, so after the do iOS presentation. I didn't do much public speaking immediately after that. But I had just written my first book as well in that year, about iOS 10. And I took the notifications chapter and made a cool talk out of that. And a lot of people like to talk about a lot of compliments and it sort of did encourage me to do more and more knowledge sharing in different ways. So what I actually ended up doing in the first few First year after probably was to do mostly talks at schools. So I went to the app Academy in Amsterdam, where I did a whole workshop about notifications. And I think I was just a few years out of out of college at that point. And they actually had me back to do a whole minor as an assistant teacher or, yeah, somewhat of an assistant teacher, I did have my own class, but I didn't make the curriculum about web development, actually, that did sort of spark that joy of, you know, make presentations talking. And I was sharing knowledge, which I already loved back then and still do. So yeah, it sort of grew from there. And then I didn't do much other than write two more books. And then last year, like one year, and two months ago or something, I started blogging again, started going to more and more conferences again. And yeah, sort of. Here we are now with more books for conferences, more talks, more meetups, more podcasts, more everything. Jeroen Leenarts: So let, let, let's go back to the beginning, so to speak. Because you mentioned that you on your website that you do that you did a lot of things with other languages as well. Yeah. So what did you do before? Do iOS? Because I remember that, like, when we first met, you're either still a student, or you just graduated, I think. Donny Wals: Yeah, that sounds sounds about right. Yeah. Jeroen Leenarts: So what made you do a education in computer science? Or what was your education actually, Donny Wals: so let's let's go back all the way to about 17 year old me probably, I started my education and interactive media design in Amsterdam. And I soon figured out that the design part was not my cup of tea. At you have to sort of explain why you chose to color pink for something and simply saying, I like pink is not good enough. And for me, it's, it was always like, I like this color. I like this shape. So it's good enough for me, but it never was for for school. But there was a small technology part there, where we could build websites with with HTML, and just the most basic stuff that you can think of. And then we went for internships. And I chose one that was recommended to me by a friend that was highly technical, that I was severely under qualified for. I was basically going in to an internship where I was supposed to be a front end developer, and all I had done was convert some PSD files to HTML slices. I don't know if you remember slicing PSD file, which is a tables, right? Yes, it's just click a drag. And then Photoshop exports. Sort of a grid of images. And that is your website. Yeah. So I only think I did was that. And then I got into ActionScript and flash, which was amazing. Cuz it was pretty easy to get started with. Because you had your timeline and all your animations and stuff you could do there and then just jump to keyframes, and you would sort of have a website? Yeah. So I, I found out at that point that I really liked development. So I started doing more and more ActionScript. And then I sort of rolled into PHP, and I graduated from that school. And then I went and continued my education. So your first language was ActionScript? Probably, yeah. Well, unless you count HTML and CSS as a language, Jeroen Leenarts: is it? Yeah, it's more declarative, but it's still programming in my mind. Exactly. Yeah. Yeah. Donny Wals: We can have lengthy discussions about Jeroen Leenarts: I don't think we have the time this evening. But I agree. It will be something for like, when we can finally do when in person meet up again. Yeah. So go ahead. So no, yeah. So I do miss those. Donny Wals: For sure. Yes, I miss them a lot. But yeah, so after that, I went off to college, and picked up an interest in more and more languages. At an internship, I did a bunch of PHP and JavaScript stuck around there. Then I moved on to a new company where I did Python, and a lot of JavaScript. And I also started iOS there, because they needed an iOS app. They hired a freelancer who was very, very expensive. And they were like, Well, you said, you like iOS? Can't you develop for iOS? Like, not yet, but I'm sure I can learn. So So I did. Okay, here I am today. Jeroen Leenarts: So you're now working at Disney streaming services, right? Yes. So what's your job there? Donny Wals: My job there is currently iOS engineer on the SDK team. And what that means is that I write all of the basically all of the network communication logic between our Disney Plus app for iOS DDoS. And our various back end services. Yeah, that includes DRM management, and all all the fun stuff. Jeroen Leenarts: So it doesn't include a lot of user interface or is it strictly networking that you're Donny Wals: strictly not strictly networking, but it definitely does not involve user interface, maybe a login screen or something like that. Not even that not even that I only built the the interfaces that our front end developers program against. Jeroen Leenarts: Okay. And Disney streaming services. That's something completely different than Disney. You mentioned in passing the other day. Yes. So what is the difference between the two? Because people they they see Disney, so this guy works for Disney. But it's right. It's a bit different. Right? Donny Wals: Right. So you have any company that's dissolved the size of Disney will have different branches, right? I mean, like, take Google, for example, which is also known as alphabet, and they have all their products underneath it. Disney has many things, too. So you have your Disney parks, you have Disney Europe, your Disney America channel, which is all ultimately part of The Walt Disney Company are on the same umbrella. But the Disney streaming services branch only concerns itself with the streaming business. Jeroen Leenarts: So that's that's Disney plus the app and the yes surface that you subscribe to. Donny Wals: Yeah. And so we also have Hulu and that kind of stuff. But those are all built, I believe, by the are sort of those are in a different branch, which are people who are in the United States, I believe are part of The Walt Disney Company directly. But I'm not I'm not even entirely sure. What branches Jeroen Leenarts: follow. Exactly. And is it a big team that you're working? Or? Donny Wals: So the team that I am in for the SDK is only four people? It used to be three, but we have a new team member who started recently. Okay. And the whole iOS department has to be around 40 people. That's significant. It is significant. Yes. And then there's the Android people where people services people, so the whole company is asked to be in the 1000s. Jeroen Leenarts: Yeah, yeah. Obviously, because it's, it's a multinational company. Yes. Okay. And so that, that that's actually a really big product that you are working on. And I won't go into numbers or details, because that's probably stuff you're not at liberty to share. Donny Wals: Liberty to see. Jeroen Leenarts: You have to subscribe to Disney plus yourself as well. Right? No employee discount? Donny Wals: Technically, no. Jeroen Leenarts: Yeah, okay. Let's not go into that too much. So and before Disney? Are there any other well known products or services that you helped develop? Or something else that you're really, as a product are very proud of? Donny Wals: So there is one product that a lot of people in the Netherlands would know, especially around him so much is called Iman, is an app where you can win free tickets for events all around the country. But of course, the whole party scenes sort of centers in Amsterdam most of the time. Jeroen Leenarts: You're within the a 10 ring, right? That's the Yes, yes. Otherwise, it's not Amsterdam, but that's the highway circling around Amsterdam. And there's a clear distinction, according to some people, that Amsterdam happens within this. This ring, and everything outside. It's a what do they call it farmers? Donny Wals: I don't know. I don't live inside the ring. So I'm not. They don't share this information with me. Jeroen Leenarts: Okay, now, well, I don't even live close to Amsterdam. So let's see. So, Deborah, besides being an employee working in a company, we also do a lot of stuff in your own time. You already mentioned you write books, you have you do speaking engagements. You also mentioned that you have provided some training to people. Can you tell us a bit about those three things that you that you work on? Why did you start doing these three things, actually. Donny Wals: So initially, what happened is I worked at a startup and the startup would bankrupt. So basically, you're If you're at work one day, and then they tell you Well, today is the last day, we just ran out of money, we just paid everybody their monthly salary, and there is no more money to pay anything. So go home, enjoy your time off, and we'll let you know what happens. Okay, so that was bad news. And I was like, so what am I gonna do? Because the way it works in Netherlands is that you, if your employer is not yet officially bankrupt, you should not go and look for a new job. Because if you do find the new job, you basically lose any pay that you didn't get during this game did you were looking so I had to sit at home for a bunch of time until they figured it out and got everything sorted in court. So after about two or three weeks, I got a message from Packt publishing. They said, Okay, do you want to write a book? So I was bored out of my mind for three weeks trying to keep myself busy? I'm like, yes, Jeroen Leenarts: yes, I want something to do something to help me hang on. Donny Wals: And it wasn't until after I signed a contract that I realized that I would probably find a new job within two weeks after everything was sorted. But writing a book takes much longer than that. So yeah, so I was sort of stuck with that for six months. Yeah. But I really enjoyed the experience of, you know, it was all around WWDC, so so I could immediately jump in, look at all the API's. Go through all the videos, quickly draft an outline for the book. Like I think this is the most important stuff in iOS 10. start experimenting, start learning start documenting, add some generic best practices. And before I knew it, it was it was around late November, I think. And the book was done. And it was available. I got a copy in the mail. And I was just looking at it like, holy cow. Did that make that I made that? Exactly. And that was so much fun. And just knowing that people would would be helped by it. Even if like one person really loved a book, I would have been very happy, but it sold pretty decent. And that feeling that you're able to help somebody achieve something is really, really cool. And that sort of triggered into. Okay, I don't want to write a book every time. So what else can I do? I can go out and talk to people and speak to people and provide some one on one teaching and, you know, help people directly in school, for example, or, Jeroen Leenarts: and you also do some blogging recently, again, yeah, recently. But Donny Wals: yes, I started like many years ago, but I restarted last year. And that was just a way to not write an entire book every time and just write little bits and pieces every week. So that that has been a ton of fun. Just seeing how many people that helps. Jeroen Leenarts: So how many books have you authored so far? Donny Wals: I have authored four and I'm currently working on my fifth. Jeroen Leenarts: And you have written a book on combined. You've also, it seems Core Data is a is a topic that's like, up there in your attention, it seems. Donny Wals: Yes. Yeah. So. So I wrote three books on just difficult mastering iOS, that's I was 1011 and 12. Stop doing those 12. And I did a book on combine. And I'm currently working on a book, that core data. Yeah, continuing so I combined book is called practical combined. And it really focuses on teaching people how to use combine, rather than going into all the fine details of what it means to do functional reactive programming and being very pure about it and bothering people, moan ads, or whatever, just wanted it to be very to the point. Jeroen Leenarts: So what made you switch from like a SDK encompassing book to more a topical book? Donny Wals: A few reasons, I felt that a book about a topic would be more fun, because you can go more in depth. Right? So so a book about the entire iOS SDK is very, like you get to dip into things. But ultimately, you never really dip in deep, because otherwise she would, you know, write a book that wouldn't fit on anybody's bookshelf. So that and also, I felt like keeping that up to date would be much easier. Right? Just focusing on that one topic. And also, it's much faster to write, which is also more fun because you get to make big steps of progress much quicker. Jeroen Leenarts: Does it also lead to easier acceptance on a conference that you can submit as a CFP on one of your books topics and then have an easier time getting through the CFP because you have such a such an in depth proven knowledge on this area. Donny Wals: So that I wouldn't necessarily know for sure. Mostly because I published a book in the beginning of this year. We all know what happened this year. No in person conferences, and the CFPs have been very different for remote conferences. Okay, in what way? It feels like, it's much easier to get into conferences this year. Which could also be like you say, sort of a nice little mix of events. I did a lot of conferences last year. So a lot of people must have seen my talk see my face. I published a book, the start of this year, so so that all probably also helped. But yeah, it feels different with with the remote conferences, also seems like it might be easier for organizers to have more speakers. Jeroen Leenarts: Yeah, yeah, definitely. Because I've seen seen conferences that are like 24 hours. It's our logical like, Wow. Donny Wals: Yes. And also, I think it's probably easier to give more people a chance to speak. Because you're not like flying them out, paying for an expensive hotel, and all those kinds of stuff. Any conference, people who are listening and not inviting people who haven't spoken before, do it. This is a chance mean, Jeroen Leenarts: the wildcard Yes, Donny Wals: exactly. suspend your wildcard Stygia. Because it's it's cheap. Alex, Jeroen Leenarts: I've been on the other end of the spectrum, organizing conferences, and it's it's true. The budget was the most expensive areas in your budgets are the hotels and the plane tickets that you have to buy for speakers that you invite to your conference, because, hey, you're inviting them. So the least you should do is make sure that they have a comfortable stay and a comfortable trip. And also, some speakers, especially if they're really headline speakers, they also request a speaking fee. And that's, that's very dependent on on your budget on, on how many sponsors how big sponsors are, whether or not you can provide them with such a coverage? Of course, the hotel and the plane tickets, yes. But on top of that, it's always difficult because I what I noticed with conferences, it's it's fun, it's a lot of fun to organize. It's also a lot of work. And there are some really high risks involved with making sure that you at least break even at the end of the day. Yeah, yes, I Donny Wals: think if there's one year where you should give people chances, it's this year, because you don't have all the other costs. Jeroen Leenarts: Yeah. Okay. Um, just just a little recap. You work at Disney streaming services, you're a blogger, you write books, you're working on your fifth set? And are there any other things that you are actually undertaking at the moment that might be of interest to people interested in iOS development? Donny Wals: I am not doing much these days. So I have to be honest. I have my guitars that I spend a bunch of time with, when I'm not writing or working. Jeroen Leenarts: Yeah. So but otherwise, what kind of guitar Do you play? Donny Wals: I play several. We have our webcam thing going that people won't see. But there's there's a bunch of them here. Yeah. Behind me. It's basically tar to electrics acoustic. And I also have an electric guitar. Downstairs. Yeah. Jeroen Leenarts: So I'm grabbing back to your books, you wrote three books that are like SDK encompassing, up to SDK 12? Yes, I think you said those are now like, less relevant to developers getting into iOS development. They've had their moments so to speak. But the combined book and the core data book that you're working on, who are you writing these books for? Donny Wals: So these are for people several skill levels, they're definitely not for beginners. Right. So if you are a person who decided to get into Swift today, both of these books are not for you at all. However, you also don't have to be extremely experienced. I think people who would have done Paul Hudson's 100 days of Swift or 100 days of Swift UI, would be able to pick up these books and understand most of it. I do try to avoid going too much into detail. For example, my core data book there is a chapter about multi threaded environments. Which means that you are going to have to understand a little bit of dispatch queues and all that kind of stuff. If you don't know GCD at all, you're gonna have a hard time. And I thought long and hard about like, should I explain to you GCD in this book, and then I decided no, this book is not for people who don't understand GCD it's for people who want to learn how to properly use core data when they are also using GCD. So it's, it's somewhere in between of like, beginners to advanced people. And you can of course pick and choose to stuff that you need and understand. So it's, it's, it's, it's for a lot Jeroen Leenarts: of people, I'll make sure to, to link to information about these books, if available. Of course, the combined book is already published. And you're probably writing about your Core Data Book development as well, every now and then. Sometimes, yeah, so I'll make sure to link what I can. Let's see, besides your own books, are there any other books resources or things that you recommend to iOS developers or any developer maybe? Donny Wals: Oh, that's a good question. Of course, there's the usual suspects, Paul Hudson, Johnson, Dell, Antoine Majeed, if you're into Swift UI. They all have websites that you can include in your show notes. I will, I don't know the URLs from the top of my head for all the thoughts, we will figure them out. Exactly. But then there's also a book that I recently read, actually, which is called, of course, I forgot the name. So let me quickly it's called algorithms to live by I just remembered. So recently read this book called algorithms to live by. And it's, it's a very interesting book, because when you pick it up, you think, okay, so these are going to be the algorithms to remember how to implement when I go for an interview at a company. And it's actually not about programming at all. Like there's not a single line of code in the whole book. And instead, what it teaches is sort of how certain algorithms take experience from real life, and how they are developed. And they also point out a couple of sort of imperfections, or almost impossibilities that we sometimes try to solve in computer science, which is sometimes not worth it, or not even possible, like problems that mathematicians may have spent dozens of years on trying to figure out this, we have decided that this is an intractable problem, there's, there is no optimal solution for this issue. Jeroen Leenarts: Computational, it's just too expensive. Donny Wals: Exactly. It's like, so you have algorithms that help you decide how to plan properly. And you can set all the variables in a way that allow you to have an optimal solution. But then when you take it into the real world, you'll figure out that there are so many different paths, that it you could probably figure out the optimal solution, but you would have to try them all. Which is not possible. Because if you have a task, and you've completed, the task has now completed and you cannot complete it again. But even if you could, it would maybe take you like 1000 years to find out what the optimal solution was. And so it's really interesting to read about that. And to see that even in computer science, good enough is often perfect. So that is a fun book to read for any developer. Jeroen Leenarts: Okay. So it's a bit in the it's been in the area of the Pragmatic Programmers are the mythical man month and basically these these these craftsman craftsmanship type book, really, Donny Wals: almost Yeah, except the other two that you mentioned, which were probably the other two that I was going to mention myself, because I love both of those books. But they are very much focused on the process of development. They help you be a better developer. And this this book, algorithms to live by is I think it would even be interesting for somebody who's into math, for example, or, you know, somebody who's just generally into algorithms, not necessarily in the context of computer science. So yeah, it's it's a fun. Jeroen Leenarts: Okay, let's switch topics a little bit. The Swift language, it's constantly being developed. We fortunately have ABI stability. So it's not that we have to like, go crazy on a code base each time a new Xcode version is released. Thank God. Yes. Did you read about the new? What is the multi threading support that they are suggesting to add to the Swift language that you had some time already to, to think about and contemplate on that? Donny Wals: Yes, well, very briefly, I have looked at it. I read the proposal. I briefly scan through the comments, which was the usual mix of this looks fantastic. And this will never work. At which point I usually kind of tap out and realize that both camps are much smarter than me. They, it is rather than often people that I think, think about this at a much deeper level than I ever probably could. But the API itself looks very, very interesting. Jeroen Leenarts: Yeah. And because they split it up in a number of phases, more like a syntax phase and a second face with a little bit more syntax, and then the, I'd call it the end game of this proposal, because the maximum benefit is only reached in like the final stage of the second phase. So what's your thoughts on that process there? But what do you think? Donny Wals: So I mean, I get that it says, probably way too big to to get out the door all at once. They probably want their their initial API to sort of sit for a while and mature while people work with it, instead of releasing it all at once. However, it does seem like, especially in the beginning, I am not sure if we gain anything other than syntactic sugar. Right? Because it essentially introduces the async and await keywords, I believe, and the actual keyword. Right, those are all part of phase one, I Jeroen Leenarts: think I think so yes. Donny Wals: And async basically just says like, hey, this, this function should run on some thread asynchronously. Jeroen Leenarts: Actually, they Donny Wals: specify. Yeah, yeah. Or do the actor I think it's what they came up. Jeroen Leenarts: To me, it looks like a syntactic sugar on top of dispatch queues, Donny Wals: basically, yes. It's I think an actor would be analogous to a dispatch queue. Right. So if you make something async, you'll basically run it asynchronously within that actor. Jeroen Leenarts: So how on top of these language proposals are you do just like, read them in passing, or it doesn't really depend on how to develop? Donny Wals: I've mostly read them in passing. It also kind of depends on how excited I am about them. I mean, this is a feature that I am moderately excited about. Because I really think that GCD is an old fashioned API that can definitely use a new lick of paint. However, it's also I know, a topic that is far beyond my knowledge to reason about at a level that would make it valuable for me to participate and stay on top of discussions. Jeroen Leenarts: Yeah. So looking at language changes that we've had over the last couple Xcode releases. Yeah, what were the language changes that you were the happiest with? Donny Wals: The happiest with? Oh, yeah. So it's, it's a very small one, but I really liked the enum all cases, Jeroen Leenarts: property, with nice looping on all of them there. Donny Wals: Yes, it's really helpful as well, if you if you're just building something where you would normally find that yourself. And then also codable, I think, is pretty great. Yeah. Although I am noticing that it's slightly slow, sometimes. Jeroen Leenarts: Okay. But is that due to the use case that you are using codable? Or oh, yes, I'm definitely as I can imagine that at Disney streaming services that you are dealing with large credit lots of, of information. Donny Wals: Oh, yes. And also, I typically tend to just abuse these kinds of API's a lot. So one thing that is interesting to do is you can take a core data model, or a managed object and encoded and then decode it to turn it into a struct. Yeah. Which is awesome. Unless you're doing that with 100 items, Jeroen Leenarts: yeah. Then it starts adding up. Yeah. Then you really want to have a more streaming like approach, I think, Donny Wals: possibly, yes. Or even just, for example, encode an entire array of managed objects into an array of structs. So you only have one pass? Yeah. Instead of 100 passes, yet. It's stuff like that where you can tell that it's not. It's not free. It's actually far from free. Jeroen Leenarts: So switching topics again, with the book writing, the blogging, the speaking does it pay the bills If you would stop working in streaming services, Donny Wals: no, not yet. And it might never pay the bill. I think the books might. But I would have to stay on top of it. Yeah, and definitely right. Like, after a coup d'etat one, I would have to probably write two or three more. That'd be I'd be good for for some time. Yeah. However, that is only because I self publish. Yeah, I really have to say that. Because I wrote books for packs before which, which was a great experience. But writing for a publisher is not going to pay the bills. Jeroen Leenarts: The motivation there is probably way different, right? Because then you have like Donny Wals: a tattoo. And and also you get like, 15% of every book sold. Yeah, maybe 20. If you're really good at negotiating. And then your publisher decides, for example, to do a sale on your book discount buying it for $10, which means that you get maybe 150, maybe $2, a copy, which is it's not a lot. Do the math, how many would you have to sell to pay the bills with that kind of money? Jeroen Leenarts: So um, Antoine, in my previous interview, had a very interesting motivation to actually do all these publicly visible things besides his day job. How do you look upon that? Is that also your motivation? Because Antoine's motivation is because he wants to learn, he likes to sharing aspects. And he really likes that he can provide something to people out there. So how does that work for you? Donny Wals: I definitely agree with it helping you learn and that it's fun to share knowledge with people. Yeah, I think these are the biggest drivers for me, too. For books, it's slightly different, because books are of course, a lot more effort. So with the books, it's also, of course, I'm very happy that it helps people that is sort of the the initial reason I want to write stuff. But the decision to do books is also so that I can get a little bit of a financial compensation for myself for my writing. Like I could publish the same stuff for free, which would probably make a lot of people very happy. But, you know, it's, it's nice to have have something to sell. And I've also noticed that there are a bunch of people in the community who, for example, after a conference talk, basically so like, Hey, I love your website, I love your talks. Where do I spend money on you? Yeah, like, how do I financially support this? Yeah. And it's nice to be able to point these people to to a book, for example. So just just by that, like, that is all I want. From people who really want to support me, it's okay, just get the book. Yeah. Jeroen Leenarts: Let's see, I'm looking at my notes. Well, we mentioned the books, we talked about where you work. We also talks about what actually motivates you to do all these things. Do you have any recommendations to people that are thinking about starting to blog or starting to write a book, probably writing a book might be a bit out there as a first endeavor. But what are your tips on on that to those people also about speaking? Donny Wals: Right? So the obvious tip there is just do it. Jeroen Leenarts: But how do you start doing it? Donny Wals: Exactly. That is the tough part. And something that that I did a lot still do is, for example, when I am learning something, or when I'm reading something, I almost pretend like I am doing a talk for myself. That's how I almost read it out loud. And if it's a blog post that I'm reading, I will try to envision what slides could look like for it. Like what would I want to see if this were talking about what I want to see on the screen right now? And maybe even like, what examples Am I missing in this text? Jeroen Leenarts: So is this when you when you're consuming some content that is relevant to iOS developers? Be it an article, a book, a talk from somebody else? Or whatever? You're actually actively taking notes? Or is it all you're taking Donny Wals: notes? I'm just pretending in my mind that it's a talk that that I am doing so basically, in my mind, stealing that other person's content getting up on stage. Jeroen Leenarts: Let's call it reflecting their behavior. Yes, Donny Wals: well, and so what that does is it does a couple of things it for me it just helps me learn that's that's why it's started doing it, it makes it easier for me to, to consumer I cannot read. You know, some people say they don't have an internal voice or whatever, like I cannot read without my internal voice, I have to have my internal voice really out to me allow except it's quiet in my head. So I started doing that. And that sort of helps me figure out how I would present something. Right? That's sort of, in my head, it evolves my speaking voice and all that stuff. And that is very good practice, I think, for doing talks. Because when you're doing that, and maybe one day you are in the shower, or you're in bed, and you have trouble sleeping, and you're just like, what if I would talk about this thing that I did today? But doodles, end of day evaluation with yourself and pretend like, even though you maybe saw something for the first time that day, pretend you're the expert, and pretend you're doing a talk in front of people like how would you talk? How would you explain what would the key concepts be? And like, that all happens in your mind, and eventually just take pen to paper, start writing it down, maybe make it a blog post, maybe make it a presentation, maybe just make it a bunch of notes that you throw away? Make it an email to yourself until you sort of build up that confidence that it's maybe good enough. Jeroen Leenarts: So for instance, in a blog post, how much time does it take for you to do the actual writing of a blog post? Donny Wals: That really depends anywhere between 30 minutes and four hours? Jeroen Leenarts: Because, um, Tom said, like, I take two hours every Monday I think it was, and I start at when the clock starts ticking, and two hours later, or whatever I have, I haven't finished and I haven't published. Donny Wals: Yeah. So yeah, so for me, it doesn't quite work like that. Because sometimes I just find that I want to go a little bit more in depth. And sometimes I realized that I didn't think something through. So I will usually spend a few evenings very passively thinking about a post and thinking about an example and thinking about what I want to explain and all that stuff. And then I sit down to write it. And if it did a good job in the days before, it's like 30 minutes done. If I didn't do a good job, it's like three or four hours, Jeroen Leenarts: when you are in this, this phase of structuring and really thinking about the content, do people around you notice that you're doing that? No, you're really quiet and Donny Wals: I'm always really quiet. Okay, that's not true. Okay. Jeroen Leenarts: And along the way, are there any things or people or organizations that really gave you a boost, we already mentioned that you you got a wildcard at a conference that probably helps to get a feel for doing that, or other other people or instances that really helped you in the saddle, so to speak? Donny Wals: Oh, definitely. Yes. So do iOS was definitely a great, great first attempt, basically are sort of getting my feet wet. And I actually got in touch with Daniel Steinberg. Jeroen Leenarts: Yeah, yeah. He's a great guy. At that conference, I have a little, I have a little secret for you. I'm going to interview him as well. Donny Wals: Very good. Very good. He would have been my suggestion to challenge at the end, I guess I don't have to challenge you. So yeah, in touch with him, and he is really great guy. Yeah. And he really helped me get better at presenting. I'd also helped me sort of develop a sort of a writing style, you know, helped me learn how to explain things. Yeah. It's really, really good guy. Jeroen Leenarts: He just loves teaching. It's, it's he does what he loves. It's what he is. Donny Wals: Even if you're having coffee with him, he cannot help himself but accidentally teach you something. Jeroen Leenarts: Even when it's past that. Okay, well, that's great to hear that. That Daniel is somebody that's well, not physically but he's like in your mind very close to you by Helping you because I really am surprised about how many people in the iOS community that are that are just willing to just help out you know, just help somebody and just share knowledge and work with each other to just come to something that is better than what you can reach individually. Are there any other parting tips or words of wisdom or maybe chicken war stories that you want to share? Donny Wals: Ah, That is a tough question. I know, words of wisdom. I think it's one of the biggest cliches but, you know, Follow Follow your heart, you know, try to do what what it is that you is your gut tells you to do something or to try something, just do it. And the worst thing that could happen typically is did you find out that you're never going to do it again. And that, especially with blogging, or whatever, just try it. If you feel like it's something you want to try, just do it. Go ahead. And if you realize your blogs are not good, you can either try to improve or decide that it's just not something that's for you, which is of course, fine. But at least you've tried. Jeroen Leenarts: People, there you have it, Donnie waltz, who's an author and a blogger himself and who does a lot of things. He's just saying to what I did, and just give it a try, maybe just like it and who knows where you end up. Thank you, Danny. Donny Wals: Thanks for having me. Those fun