Episode #47: Programming AWS Lambda with Mike Roberts

About Mike Roberts: Mike Roberts is a partner, and co-founder, of Symphonia - a consultancy specializing in Cloud Architecture and the impact it has on companies and teams. During his career, Mike’s been an engineer, a CTO, and other fun places in-between. He’s a long-time proponent of Agile and DevOps values and is passionate about the role that cloud technologies have played in enabling such values for many high-functioning software teams. He sees Serverless as the next evolution of cloud systems and as such is excited about its ability to help teams, and their customers, be awesome.Twitter: twitter.com/mikebrobertsLinkedIn: linkedin.com/in/mikebrobertsWebsite: mikebroberts.comSymphonia: www.symphonia.ioSymphonia blog: blog.symphonia.ioProgramming AWS Lambda: Build and Deploy Serverless Applications with Java book: shop.oreilly.comWatch this episode on YouTube: https://youtu.be/16en-TTGNhkJeremy: Hi, everyone. I'm Jeremy Daly and this is Serverless Chats. This week, I'm chatting with Mike Roberts. Hey, Mike, thanks for joining me.Mike: Thank you very much for inviting me, Jeremy.Jeremy: So, you are a Cloud Architect and DevOps Consultant that specializes in serverless and AWS, and you're also a partner at Symphonia. So, why don't you tell the listeners a little bit about your background and what Symphonia does.Mike: Yeah, that'd be great. So, I've been in industry now for 21 years and in that time, I've been an engineer or a senior engineer, manager or CTO, sometimes consulting, sometimes working for product companies, so a whole mixture and sort of up and down the manager versus technical ladder.About four years ago, I was a VP of Engineering at an ad tech company here in New York and we started using a lot of sort of much higher level AWS technologies and especially at the end of that year, we were using a lot of Lambda, so I really thought that serverless was really interesting and so I wrote an article four years ago now about serverless. That proved to be really popular and I was like, "Oh, wait, other people like this, too. Maybe I should start a company about this kind of stuff." So myself and my business partner, John Chapin, we decided to start Symphonia as a consulting company to help people with the kind of technologies and lessons that we'd sort of seen over the last few years. And that's what we've been doing now for three and a half years.Jeremy: Awesome. Alright. Well, so recently, you and your business partner, John, wrote a book called Programming AWS Lambda, and great title, right, there it is. He's got it. Okay. Now, the thing that struck me though about it was about Java. And so I'm just curious, it's 2020 and so, why would you write a book about serverless programming in Java?Mike: Mostly because my writing is terrible and I didn't want anyone to actually read the book. No, that's not the  reason. It is weird and a lot of the things that you read about Lambda, the examples are in Python or JavaScript or Go and then there's this Java thing. And who actually uses Java with Lambda? Well, it turns out a lot of people use Java with Lambda and the other thing was, it's how we got started with Lambda. So when John and I started using Lambda, which was about three and a half years ago, the Java support has just come out and we were working for a Java shop, so we had a lot of engineers who were very Java savvy. We had all of our Java tool chains all sorted out and so we decided to use Java and Lambda and see how it worked and it worked brilliantly.And one of the reasons it worked brilliantly was that the system that we were building was pretty high throughput, like we were processing millions of messages a day with Lambda and so we never hit, and even back then, any of the concerns with cold starts or anything like that, and so yeah, it really just fitted in like a glove for us and. And so, when we decided to write the book, we knew that we weren't unique and we knew that there were a lot of other people out there who have built up this knowledge in Java and the ecosystem that surrounds Java and we wanted them to have a book for Lambda, just like JavaScript developers and Python developers and all that kind of thing.Jeremy: Awesome. Well, so the funny thing is, is that I saw this book come out and I immediately was like, "Oh, no, it's a book about Java." And I haven't programmed in Java, and I don't remember how long, but I said, "I know Mike and I know John." I've been following your work for a couple of years now and I know you produce good stuff. So I said, "I'm going to look at it. I just want to give it a look." And what I found was that it's not really a book about Java. It's really a book about building serverless applications with the examples in Java and there are a few very Java specific things in there, which I think is actually great and we'll get into some of those reasons why.But yeah, but I mean, the book covers everything. All those core concepts like the execution environment and invocation types, logging, timeouts, memory, CPU, environment variables, all those things that you would want to know and it gets into detailed explanations about deployments, infrastructure as code, security, event sources, so it really is a much more complete reference. So, if you pick up this book or if you don't pick up this book, because you're like, "Oh, it's about Java."I actually would really suggest that you pick it up and just read some of the core concepts because I really like your take, you and John's take, on just some of these different concepts because I think there's a lot of, I don't know if dogma is the right word, but there's people who approach things a certain way and they just sort of think that's the way to do it, but when you start applying those things to real world situations and real applications, you start to butt up against some of the limitations. Anyways, you had some really interesting thoughts on that.Mike: Well, thank you.Jeremy: So I want to get into the book because there's some really interesting things and I know I'm talking more than I probably should be here, but this is something that I found really interesting was your approach to testing.Mike: Yeah, and it's interesting, because John and I, we actually only met about five years ago and we both been working 20 years, but the way that we approach Development and Engineering in general is extremely similar. I mean, I come from 20 years of extreme programming and test-driven development and that background and John does to some extent, but not quite as in... I was working with people that were speaking and writing about this stuff back 15 years ago, but yeah, we very much felt the same way.And while I don't, I'm not a test-driven developer all the time, I don't always write my tests first. What I learned from when I did write that way 15 years ago is to rely on unit tests and functional tests that are of a specific type and John feels exactly the same way. In fact, John was the primary author on that chapter in the book and it's interesting because I completely agree with everything he ...