Kotlin Engineer - Server Side

11:FS | London, England
Flexible hours
More than 2 days at home per week
Dog friendly
Employment type
Full time
Key skills
Engineering, Java
Competitive Salary + Pension Scheme at 4% matched

11:FS are looking for Kotlin/Java engineers to join them in building digital propositions for - and with - their clients. You will be part of 11:FS' engineering tribe, and you’ll be working with colleagues from Product, Design, Research and their other tribes in teams that are truly cross-functional, and where you will see the direct impact of the work you do.

11:FS is on a mission to change the fabric of financial services. Our Consulting & Research practice builds challenger propositions globally, like we did for Natwest with Mettle. Our Pulse team creates a benchmarking tool used by the likes of Monzo, Starling, Natwest and Tesco Bank. Our Foundry team are delivering a Financial Services Operating System to help businesses quickly add financial services to their offering. On top of all of that, we’re a media company, generating content that supports our brand and changes the conversation - not necessarily in that order.

To do this we need an amazing team so we have pulled together the best in financial services and beyond.

We truly live our values at 11:FS, and they are critical to your entire journey here. ‘Cultural Add’ is as, if not more, important as pure technical fit, and as part of your interview process we’ll deep dive in our values and your beliefs. Everyone at 11:FS fits our 4 core values: Team, Attitude, Communication and Impact, and this remains at the core of our growth.

We are looking for well-rounded engineers to join us in building truly digital propositions for - and with - our clients. You will be part of our engineering tribe, and working cross-functionally with other tribes from Product, Design and Research to deliver impactful work, and where you will see the direct impact of the work you do.  

About the role

Our preferred server-side language is Kotlin, and we are building a strong capability with this language. We’re hiring for the long-term, and we value people who want to grow with us and bring something to our culture. You don’t necessarily need to be a Kotlin expert, but you should have some experience, and be keen to build your knowledge (you may be a Java engineer who has embraced Kotlin on side projects, and is keen to explore it further.) We want to grow a team of multi-skilled engineers who are passionate about building products and services, and who pick the right technology for the job. Your focus will be on server-side engineering, designing and building performant cloud-native services with clean APIs, most likely on one of our client engagements. We believe in teams that are greater than the sum of their parts, and you’ll be working closely with product managers, designers and other experts in their fields. We like short feedback loops, code reviews, and occasional pairing. You may also need to perform rapid prototyping, ‘spiking out’ quick and dirty software in order to demonstrate a concept before turning it into something more ‘production-like’.  We’re believers in autonomous teams and iterative development. We’re crazy about continuous improvement and knowledge sharing, and we want people who share our enthusiasm. We know that building high performance, highly scalable, always available, fault tolerant systems is a team game and so we want to know that you play well with others. Lone geniuses are brilliant - just not for us.

About you

You are someone who’s passionate about technology, but particularly for what you can build with it (rather than for its own sake). You’ll be building financial applications and services, so you’ll need a strong balance of creativity and rigour, together with some pragmatism around delivering for clients. We value simplicity, and believe that ‘successful’ complexity derives from the combination of many simple components. We encourage ownership, and we’ll also expect you to develop ‘T-shaped’ skills, working with your team to what’s needed to deliver to the client. 

You should also understand good software component design, and be able to identify where we can create reusable ‘building blocks’ to accelerate our engagements.

  • You prefer to work in an iterative fashion. You are adept at slicing your work to deliver small and often, working with colleagues to deliver together.
  • You’re happy working as part of a cross-functional team, able to understand the context of what the team needs, and willing to be pragmatic. 
  • You’re willing to step outside of your part of the tech stack, and learn new technologies in order to get the job done.
  • You’re aware of the bigger picture, continuously thinking holistically about what the team is delivering, and how it can be improved.
  • We believe that the very best solutions derive from seeking diverse opinions and points of view, and you need to be willing and able to modify your approach when working with your colleagues. There is always room for passion and compassion.

Specific technical skills

  • You have been building services and applications on the JVM - possibly as a Java developer - and exploring Kotlin more recently.
  • You’re familiar with microservice architectures (the advantages and drawbacks), and you’ve built and deployed containerised services to Cloud-based orchestration layers and platforms.
  • You’re familiar with TDD, you know what a good unit test looks like, and you can write tests across the test pyramid.
  • You’ve implemented well-designed APIs, you know what a good RESTful API looks like, and you may have some experience with GraphQL
  • CI/CD - you’re keen to automate away repeatable tasks to make them safe and ‘boring’, so you can focus on the higher-value parts of what you’re building.
  • You’re familiar with one or more of the major Cloud providers.


  • Profit Share Scheme
  • Flexible working
  • Private medical
  • Pension - match up to 4%
  • Income protection
  • Life assurance
  • Enhanced maternity, paternity & adoption leave
  • Free eye test and contribution to eye wear for VDU
  • Corporate gym membership
  • Season ticket loan
  • Birthdays off (or your childs or anyone else you love’s birthday)
View company profile
Flexible hours
More than 2 days at home per week
Dog friendly