Ahead of their UK arrival we caught up with Cliff Hazelton, CTO, STASH


Louize Clarke | January 15, 2020

Cliff Hazelton serves as Chief Technology Office at STASH, one of the fastest-growing consumer investing and banking platforms in the U.S., pioneering the future of financial services. Cliff’s engineering expertise spans 15+ years across fields, including Boeing Intelligence & Analytics, Capture Media and the U.S. Army Research Laboratory. 

Can you share about your career journey?

My journey to the world of programming began a long time ago. I was coding when I was about 10 years old on my dad’s Apple. I remember writing a few programmes in Basic.

I was really interested in dungeons and dragons so I used to write my own ‘choose your own adventure’ fantasy novels that had conditional logic that bridged one way or another, which was interesting – it was a fun foray into the world of software engineering. 

Many years later, when I decided to declare my undergrad major, I decided on physics and so I spent several years not in the world of software development but the bug bit me again, when I was working in that industry. I found myself more and more attracted to the world of software and building things with software and so one of the things that drove me to go back to grad school for computer science was how much I enjoyed programming.

And what was your experience before joining stash?

I worked for a startup right out of grad school in the Defence Intelligence space, so it was a unique kind of startup, one that I hadn’t imagined myself in and we were ultimately acquired by Boeing, so it was a small company but then I got the chance to get exposure to a rather rather large company. 

I spent about five years there and then really wanted something that was a lot smaller and more intimate, something to build from the ground up, so I moved my career into New York City and started working for a small startup called Capture and worked there for several years. I helped build the team there, ultimately leading to the acquisition by a company on the West Coast called Tagboard. After that I ended up freelancing and spent a lot of time with a former iOS engineer at Capture, who was at the time working for Stash, and I was really intrigued by the work that was happening at Stash. The team seemed really great and the mission itself. Hearing Brendan and the co-founders talk about the company and what they were building was intriguing so when a leadership opportunity opened up at Stash I decided to join.

Stash is an amazing platform that brings your world into one for banking and investing. But there’s also many healthy habits that helps consumers develop too.

That’s one of our goals, to be the financial hold for users, and to be the place where they can come and manage their money end to end. Banking is pretty much a familiar and common thing for a lot of people – your everyday spend, how you manage your money, what you need to spend. We have a fantastic programme called Stock-Back which we see as the bridge between banking and investing because users with their everyday spend, every time they swipe their debit card, they get fractional shares of stock back, regardless of where they spend. We think that’s a great programme which encourages really great money habits. 

So, in addition to banking, to current money management, we also have saving and investing. One of the things we do is try to help you manage your money end to end, from the money that you need now to the money that you’ll need in the future. Our investing platform has a robust offering in terms of ETFs and stocks, it has really great educational content to help users discover the world of investing – that’s one of the things that not a lot of people have ventured into prior to finding Stash so we try to make it as accessible as possible. We offer fractional shares so you can invest with as little as $5. You don’t have to have the money required for a full share, you just need to have money and have a strategy, and we try to help you develop that strategy.

Can you share about the engineering team at stash?

With the complexity of the world of money and investing, we try to build a platform that can support the demands of the product, the demands of the customer, the demands of high throughput, we have 4 million customers now, and all indications are that we will continue to grow so we want a reliable and resilient platform. 

We use a lot of really great vendors to help us achieve that reliability and we also write a lot of cool software and leverage a lot of cool open source technologies such as Kafka and Terraform and we write a lot of our code in Scala and Ruby on the back end. On the front end we build our apps natively so iOS engineers build in Swift and Android engineers build in Kotlin. Our web engineers built the web app using react JS, JavaScript and TypeScript. We try to use pretty modern and fun to work with technology. 

Our architecture is moving from a monolithic world, it’s kind of typical when you have a platform that is built early on, you have a single back end application that is your data access layer. We’re moving to a more modular service oriented architecture and part of that strategy is to aggressively publish events, so this event driven architecture is something that we found to be very beneficial, not only for accomplishing the aggregation of data in our platform to our data lake for internal business units, but also to innovate products. So I mentioned Stock-Back earlier, one of the things that’s cool about Stock-Back is that it was built using these event driven principles

So we’re working with a lot of great technology, we are a very dynamic and fast moving team, we don’t say no very often unless it doesn’t make any sense. People are free to experiment with things. We have a lot of initiatives – we hold quarterly hackathons with no holds barred during the events, we’ve seen a lot of really cool innovation and a lot of things that we do during the hackathon actually ends up making it into the product. Not as a direct result of the hackathon but with careful product iteration after the fact, of course, but a lot of our really cool ideas come out of that.

You talked about the rapid growth and you’re still hiring, so how do you evaluate talent to join the engineering team at Stash?

We hire based on roles so if you’re an Android engineer that processes a little bit different than if you’re an iOS engineer, web engineer, QA, or back end that’s fine. We do encourage a pretty rigorous amount of cross skilling when somebody is here, our employees have the opportunity to get exposure to whatever platform that they want to work on once they’re here because we organise our teams cross functionally. 

The interview process itself is focused on candidate expertise and one of those core areas of focus. As an example, the back end interview process is very focused on some backend specific technology and some backend specific concepts. We do architectural design and we are pretty big believers in pair-programming here so we do a lot of pairing during the interview process, from the initial remote interview code-pairing session that happens when you make first contact with the candidate to when they come into the office. We try to make it representative of what your day to day work would be like at Stash – we are a very collaborative environment so we try to make the interview collaborative as well.

So why is now the ideal time to join the Stash expansion into the UK?

We are poised for some pretty exciting growth I think in the next 12-24 months. Since I’ve been here in the past two and a half years we have scaled from 15 or 20 people to 270 so who knows what the next year will hold but we’re targeting some pretty aggressive growth metrics both in the company with employees and also with our platform. 

Now is a great time to help the world learn about investing and to improve financial lives. It is one of the things that we’re aiming for, not just to be a successful business but to affect social  change. Investing and good money management, general good spending is something that is a really important thing to us and that’s one of the reasons why we see a lot of people joining this company, because they want to be a part of that.

We hear a lot from our customers, we love talking to our customers – we love when Stash is working for them. Seeing that positive impact is a fantastic thing, it’s really rewarding. Speaking as someone that has worked here for the past two and a half years getting the chance to increase the number of people that we’re helping around the world is something that we’re pretty excited about over the next two years.

Get the top featured stories in your e-mail and don’t ever miss out on important news.