Senior Kotlin Engineer

🔒 Confidential Employer
Posted 28 April 2026
LOCATION
London
TYPE
Full-time
LEVEL
Mid-Senior level
SALARY
£140,000 / year
CATEGORY
Fintech
This employer holds a UK Home Office sponsor license — sponsorship for this specific role is at the employer’s discretion

SKILLS

Kotlin AWS Docker Kubernetes GraphQL Postgres RabbitMQ Gradle

FULL DESCRIPTION

Senior Kotlin Engineer

[Employer hidden — view at passion-project.co.uk]

London

Hybrid

Full-time

Mid-Senior level

Salary: £70k-£140k

Job Description

We're looking for an engineer with a depth of knowledge and recent hands-on Kotlin experience that enables them to not only deliver elegant, idiomatic solutions in Kotlin but also to contribute new knowledge and experience to our frequent collaborative design forums with stakeholders from every area of the business

Backend: Kotlin 1.7.20, AWS, GraphQL (it would be nice if you were familiar with this but it’s not a deal breaker), Postgres, RabbitMQ, Docker, Kubernetes

Frontend: React & React Native, TypeScript, MobX, Redux, Stylus and SASS

We build our Kotlin projects using Gradle and GitHub Actions, deploying to production as soon as we finish a feature

We use JUnit Jupiter, Kotest and TestContainers for automated testing

Strong commercial Kotlin experience

An ability to write simple, clean code

Experience and understanding of databases; relational databases are a must, NoSql would be nice too

Be able to quickly understand complex, financial business domains

Understand different software architectures rapidly

Understands abstraction and interpolation

Able to write comprehensive, automated tests at all levels of the pyramid

Understanding of the Kanban agile methodology; not a deal breaker if you don’t

Someone who can get along with others and build relationships

Someone who wants to continually learn, improve and collaborate

Someone who can solve problems on their own but also knows when to go to their peers for help

Someone who is a rational thinker and is aware of the ‘why’ behind the way they do things

Someone who is a pragmatist who can sensibly weigh the tradeoffs between code quality and delivery

What the job involves

As we continue to build upon the diversity of our team we are thrilled to have the opportunity to bring on board a Senior Kotlin engineer to a newly forming pod

This is an opportunity to bring new experience, perspective and capabilities to our design discussions, helping shape our approach to delivering elegant solutions to complex engineering challenges as we continue to grow

This is the team that put the Tech in FinTech, our current tech team is around 80 strong and have helped transform finance by building a next-generation lending platform, a next-gen credit card, and auto-finance product, and they’re at it again with brand new product launches this year

There’s a lot to do, from building and integrating new API’s to help build out our new collections function to creating new internal tools and supporting our expansion of new products and supporting services in the US

Application process

  • A 30 minute introductory call with one of our engineers
  • A short coding exercise to complete in your own time
  • Onsite or Video Interview lasting 60-90 minutes, comprising of:
    • Introduction of the team and kind of work you could be doing daily
    • Discussion around the coding exercise you completed
    • Interactive architecture/design exercise
    • Tech project walkthrough
    • Cultural/behavioural questions to see if you’d be a good fit for [Employer hidden]
    • Questions you may have about the company, role, etc

Company Benefits

  • Best-in-class compensation, including equity
  • Comprehensive private health insurance (including dental, optometry and general wellbeing)
  • Multiple opportunities to socialise with your team and the wider company
  • Equipment provided for you to do your best work!
  • You can work from home every Monday and Friday if you wish - on the other days we all come together IRL to be together, build and exchange ideas (hybrid)
  • Our in-house chefs prepare fresh, healthy lunches in the office every Tuesday-Thursday
  • EV car scheme (Octopus)
  • Cycle to work scheme
  • Pension
  • 25 days of annual leave - excluding bank holidays
  • 50% off gym memberships at Virgin Active and Nuffield (via Vitality health insurance)
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