Senior Kotlin Engineer

🔒 Confidential Employer
Posted 21 March 2026
LOCATION
London
TYPE
Full-time
LEVEL
Mid-Senior level
CATEGORY
Technology
This employer holds a UK Home Office sponsor license — sponsorship for this specific role is at the employer’s discretion

SKILLS

Kotlin AWS GraphQL Postgres React Databases

FULL DESCRIPTION

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.

About the role

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.

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.

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.

We believe that software engineering is more than just code - it’s about people. We believe that the best teams are made of great people. That fundamentally great software engineering is about alignment, sharing what we know and being nice to each other. When we put all this together we make software engineering better by continually improving our capabilities as a team and making our working environment a happy and productive place.

There is more to read about us and our Lendies in the engineering blog right here and if you’d like to check our reviews out on Glassdoor you can see these here.

Our Tech Stack

*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

*Other*

  • 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

What technical skills you’ll need to have

  • 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

What kind of person you’ll need to be

  • 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

Interview 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 — view at passion-project.co.uk]
  • Questions you may have about the company, role, etc

Check out our blog

We also have an engineering blog where we have written in more detail how we work in the engineering team.

Life at [Employer hidden]

  • The opportunity to scale up one of the world’s most successful fintech companies
  • Best-in-class compensation including equity
  • 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
  • Our in-house chef prepares fresh, healthy lunches in the office every Tuesday-Thursday
  • Encouraged and sponsored personal and team growth through our training budget, 10% time for all engineers and active guilds

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