Episode #105: Building a Serverless Banking Platform with Patrick Strzelec

Serverless Chats

About Patrick Strzelec

Patrick Strzelec is a fullstack developer with a focus on building GraphQL gateways and serverless microservices. He is currently working as a technical lead at NorthOne making banking effortless for small businesses.

LinkedIn: Patrick Strzelec
NorthOne Careers: www.northone.com/about/careers

Watch this episode on YouTube: https://youtu.be/8W6lRc03QNU

This episode sponsored by CBT Nuggets and Lumigo.

Transcript
Jeremy: Hi everyone. I'm Jeremy Daly, and this is Serverless Chats. Today, I'm joined by Patrick Strzelec. Hey, Patrick, thanks for joining me.

Patrick: Hey, thanks for having me.

Jeremy: You are a lead developer at NorthOne. I'd love it if you could tell the listeners a little bit about yourself, your background, and what NorthOne does.

Patrick: Yeah, totally. I'm a lead developer here at NorthOne, I've been focusing on building out our GraphQL gateway here, as well as some of our serverless microservices. What NorthOne does, we are a banking experience for small businesses. Effectively, we are a deposit account, with many integrations that act almost like an operating system for small businesses. Basically, we choose the best partners we can to do things like check deposits, just your regular transactions you would do, as well as any insights, and the use cases will grow. I'd like to call us a very tailored banking experience for small businesses.

Jeremy: Very nice. The thing that is fascinating, I think about this, is that you have just completely embraced serverless, right?

Patrick: Yeah, totally. We started off early on with this vision of being fully event driven, and we started off with a monolith, like a Python Django big monolith, and we've been experimenting with serverless all the way through, and somewhere along the journey, we decided this is the tool for us, and it just totally made sense on the business side, on the tech side. It's been absolutely great.

Jeremy: Let's talk about that because this is one of those things where I think you get a business and a business that's a banking platform. You're handling some serious transactions here. You've got a lot of transactions that are going through, and you've totally embraced this. I'd love to have you take the listeners through why you thought it was a good idea, what were the business cases for it? Then we can talk a little bit about the adoption process, and then I know there's a whole bunch of stuff that you did with event driven stuff, which is absolutely fascinating.

Then we could probably follow up with maybe a couple of challenges, and some of the issues you face. Why don't we start there. Let's start, like who in your organization, because I am always fascinated to know if somebody in your organization says, “Hey we absolutely need to do serverless," and just starts beating that drum. What was that business and technical case that made your organization swallow that pill?

Patrick: Yeah, totally. I think just at a high level we're a user experience company, we want to make sure we offer small businesses the best banking experience possible. We don't want to spend a lot of time on operations, and trying to, and also reliability is incredibly important. If we can offload that burden and move faster, that's what we need to do. When we're talking about who's beating that drum, I would say our VP, Blake, really early on, seemed to see serverless as this amazing fit. I joined about three years ago today, so I guess this is my anniversary at the company. We were just deciding what to build. At the time there was a lot of architecture diagrams, and Blake hypothesized that serverless was a great fit.

We had a lot of versions of the world, some with Apache Kafka, and a bunch of microservices going through there. There's other versions with serverless in the mix, and some of the tooling around that, and this other hypothesis that maybe we want GraphQL gateway in the middle of there. It was one of those things that we wanted to test our hypothesis as we go. That ties into this innovation velocity that serverless allows for. It’s very cheap to put a new piece of infrastructure up in serverless. Just the other day we wanted to test Kinesis for an event streaming use case, and that was just a half an hour to set up that config, and you could put it live in production and test it out, which is completely awesome.

I think that innovation velocity was the hypothesis. We could just try things out really quickly. They don't cost much at all. You only pay for what you use for the most part. We were able to try that out, and as well as reliability. AWS really does a good job of making sure everything's available all the time. Something that maybe a young startup isn't ready to take on. When I joined the company, Blake proposed, “Okay, let's try out GraphQL as a gateway, as a concept. Build me a prototype." In that prototype, there was a really good opportunity to try serverless. They just ... Apollo server launched the serverless package, that was just super easy to deploy.

It was a complete no-brainer. We tried it out, we built the case. We just started with this GraphQL gateway running on serverless. AWS Lambda. It's funny because at first, it's like, we're just trying to sell them development. Nobody's going to be hitting our services. It was still a year out from when we were going into production. Once we went into prod, this Lambda's hot all the time, which is interesting. I think the cost case breaks down there because if you're running this thing, think forever, but it was this GraphQL server in front of our Python Django monolift, with this vision of event driven microservices, which has fit well for banking. If you just think about the banking world, everything is pretty much eventually consistent.

Just, that's the way the systems are designed. You send out a transaction, it doesn't settle for a while. We were always going to do event driven, but when you're starting out with a team of three developers, you're not going to build this whole microservices environment and everything. We started with that monolith with the GraphQL gateway in front, which scaled pretty nicely, because we were able to sort of, even today we have the same GraphQL gateway. We just changed the services backing it, which was really sweet. The adoption process was like, let's try it out. We tried it out with GraphQL first, and then as we were heading into launch, we had this monolith that we needed to manage. I mean, manually managing AWS resources, it's easier than back in the day when you're managing your own virtual machines and stuff, but it's still not great.

We didn't have a lot of time, and there was a lot of last-minute changes we needed to make. A big refactor to our scheduling transactions functions happened right before launch. That was an amazing serverless use case. And there's our second one, where we're like, “Okay, we need to get this live really quickly." We created this work performance pattern really quickly as a test with serverless, and it worked beautifully. We also had another use case come up, which was just a simple phone scheduling service. We just wrapped an API, and just exposed some endpoints, but it was just a lot easier to do with serverless. Just threw it off to two developers, figure out how you do it, and it was ready to be live. And then ...

Jeremy...