Travelex chief architect: Invest in serverless now or risk being left behind

Travelex's Dan Phelps says that moving from microservices to serverless has let the business focus on financial services, not hardware maintenance

Serverless is the latest trend in the cloud computing market: a complete separation between code and servers. Instead of leasing space on a virtual machine, companies only pay for the resources that they use; and while that might seem very similar to traditional cloud computing, in practice it means that the customer has no concerns about hardware management (or as one of our CIO contacts put it, "You're using somebody else's server but you pretend it's not a server").

Dan Phelps, chief architect at foreign exchange company Travelex, is a fan of the serverless phenomenon. "If companies aren't seriously looking at serverless today...then in five years' time they're going to be left behind," he warned.

As a brand, Travelex only undertook its own cloud migration in the last five years. The company adopted a microservices and microservice-platform-as-a-service approach, using Docker and automation tools, and is now migrating its monolithic applications to the same design pattern.

However, nothing stands still in the cloud world. While microservices were the correct approach three or four years ago, Travelex is now using "a lot more serverless" - primarily AWS Lambda.

The reason for that move is, as one might expect, to take advantage of the main selling point of serverless computing: no hardware management.

"The bottom line is, we want to sell foreign currency and provide financial services to our customers and our B2B partners - [but] we don't want to be experts in managing infrastructure. Serverless provides us with that on-demand ability to be able to create our application services and focus our technology energies on that, rather than maintaining servers."

Travelex began experimenting with serverless in the distant past of two years ago, when Lambda was still very new. The first trial was using it as part of a queuing solution for its new Supercard product, which had a "huge" marketing launch and needed a way to throttle user registrations.

"Lambda was all quite embryonic at the time, but we came out with a solution that we branded Super Queue and worked with AWS on that… That was quite successful, and proved the point that we could transition from microservices to serverless and run simple workflows using Lambda."

Phelps believes that serverless will be "the next wave of enterprise computing," and has committed to transforming Travelex's legacy applications and legacy data estates into more cloud-based and serverless platforms.

That isn't to say that serverless is without risks. The ease of deploying code, which you only pay for when it is used, can lead to poor hygiene and security vulnerabilities. Good security practice and regular audits are essential to staying on top of the wider attack surface that can result.

The other oft-cited problem is vendor lock-in, with developers building API calls that tie ever-deeper into a single platform. There's no easy solution; Travelex has used other public cloud providers for serverless, but settled on AWS for the majority of its work. If that does end up having been the wrong call, though, it will need to rewrite applications when switching. For now, though, Phelps is happy with the choice:

"What we want to be able to do is focus our best people on the things that really matter to the business, and we want to consume new technology as commodities from these providers and onboard that technology quickly.

"For us, if the public cloud providers can do that and...can democratise that new technology quickly - which means that our business users and product teams etc. can onboard that technology quickly and deliver value for the business - then that for me is one of the most important things that has driven much of our approach when it comes to cloud."