My experience as a Wise Engineering Intern

Britannio Jarrett
Wise Engineering
Published in
4 min readSep 16, 2022

I’m Britannio, I study Computer Science at the University of Southampton and this summer I spent twelve weeks as a Software Engineering Intern at Wise! This post aims to shed some light on what I got up to as an intern and what makes it so captivating to work here.

A headshot of me in the office. Shout out to Adnan 📸.

The first week at Wise

June 27th marked the first day of this internship. Commuting to the London office for the first time was an experience in itself. From getting up early to trying the Elizabeth line for the first time, and getting lost in Shoreditch despite using Google Maps, alas. The day was spent meeting fellow London interns, setting up a work laptop, indulging in poke bowls for lunch and meeting my lead virtually.

Escaping London

Money without borders is Wise’s mission so it was quite fitting to take a trip to Northern Europe, specifically Tallinn, the capital of Estonia and the heart of Wise. After settling into Tallinn for a day, Wednesday saw interns based in London, Tallinn and Budapest unite for the first time.

Tallinn is home to Wise’s largest office. All interns spent the next two days there to complete a range of onboarding activities. Highlights include meeting some of my team face to face, presenting ideas in group sessions, exploring Tallinn and bowling with everyone on the last day.

Summer sunset in Tallinn with a handful of interns.

My first project in fintech automation

Nicknamed ARUCS, the focus of my project was to rethink and automate some of the manual steps taken by our operations team when rejecting and returning invalid payments. Specifically, invalid payments received via BACS (Bankers automated clearing service).

BACS, a UK payment system introduced in 1968, is still used to pay the majority of salaries and it is the system behind direct debits. An important note is that BACS payments take three working days to be processed. More on UK payment systems can be found via https://wise.com/gb/blog/chaps-bacs-swift-faster-payments.

Quirks of the nation’s highest volume payment system

Banks occasionally request us to recall a payment they sent. This happens on day 2/3 of the transfer when the payment is imminent but before the money has reached us.

Another problem arises when a payment is sent to a closed or non-existent account.

To save our operations team the burden of returning these voided payments one by one, we sought an automatic approach.

https://xkcd.com/1319/

Teaching an old service new tricks

The solution revolves around a feature of BACS known as an ARUCS (Automated Return of Unapplied Credits Service) advice, a report we can submit to the BACS system to initiate a refund of voided payments.

Collaborating with our UK operations team, I extended our back-office UI with the functionality to reject a recalled payment and download the generated ARUCS report.

We released changes in small chunks on a frequent basis. Paired with canary deployments and automated testing, we had the confidence to roll out my contributions to production right from the get-go.

The project spanned four microservices and, 45+ pull requests later, the core elements of the project were complete. We tested the generated report with some live payments and it worked on the first attempt!

A few interns chilling in the games room.

The secret to constant innovation

Before Wise, the largest company I worked for had 40 employees. At Wise, we’re 100x larger. Scale brings many benefits to an organisation but for us to remain competitive and storm towards our mission, a team structure synonymous with rapid iteration is paramount.

No startup, no disruptor, has ever succeeded with a mere average execution speed — Kristo Käärmann, co-founder & CEO of Wise

Wise’s differentiator comes in the form of autonomous teams. Small teams that are largely independent of each other and can execute autonomously. I worked in the UK Core Team alongside five engineers and a product manager, split between London and Tallinn. Check out some of my team’s pioneering work via https://wise.com/gb/blog/transferwise-faster-payment-service.

Wrapping up a summer of sauna

The past twelve weeks have been a blast, completely exceeding my expectations for a summer internship. The weekly Lunch & Learn Q&A sessions with various influential members of Wise have deeply inspired me. Post-lunch ping-pong will be missed dearly. Team lunch on Fridays never failed to disappoint, and what better way to end a Friday than with kitchen karaoke or a visit to the office sauna?

Huge thanks to my team, my allocated buddy, the early careers team and all the interns for making this summer an unforgettable experience!

All interns jumping in the Tallinn office.

P.S. Interested in working with us? We’re hiring! Check out our open Engineering roles here.

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