Senior Full Stack Engineer II (Train)

We're putting together a talented team to build the #1 training platform for Runners

We help everyday runners become outstanding by building an incredible app providing world-class training, coaching and community for everyone, whether you're improving your 5k time or training for your first marathon.

We’re growing extremely fast! In November 2023 we closed a $6.5M funding round led by JamJar with participation from Eka Ventures, Venrex and Creator Ventures. In 2024, we were selected by Apple as one of three global finalists for the iPhone app of the year, reflecting the innovation and impact of what we’ve built & in 2025 we were acquired by Strava!

Our ambition is huge: to become the go-to global leading training platform for millions of runners everywhere. We’re growing with purpose and looking for people who want to build something meaningful with lasting impact. With the recent acquisition by Strava accelerating our journey, now is a really magical time to join. 🚀

We are looking for talented, creative and positive team players to join our highly-skilled cross-functional engineering team. You’ll sit on the Train Team where you will work closely with our modelling teams to integrate features that are core to Runna’s mission (think adapting plans around holidays and B races, supporting new cutting edge plans, and building in-app experiences around our AI/ML tooling).

You will work closely with our CTO, and engineering leadership team to help shape the future of Runna, who will support you all along this exciting journey. We have a jam packed roadmap, with countless opportunities to champion new technologies, work on meaningful problems that impact millions of runners, and improve existing architecture to elevate the whole of our engineering team.

• Architecting, building, testing and delivering new features across the full stack

• Working with the Product team to identify the most suitable solution for the best customer experience

• Collaborating with modelling/AI engineers to design architecture used to interface between the Runna training engine and Runna app

• Always be on hand to help other team members when they need help on technical matters

• Coach and support engineers in your team, providing guidance, mentorship, and code reviews without creating bottlenecks.

• Help us operate more efficiently, by building and maintaining our developer tooling and CI/CD pipeline

• We rotate the responsibility of releases across each team member, so you will get the opportunity to lead the process and deploy changes to production

• Impacting the wider engineering team by championing new technologies and setting standards for engineering quality

• Very proficient in TypeScript/JavaScript development

• Able to work in a highly skilled engineering team in a fast-paced, iterative environment. In 2024 we shipped:

  • 99 mobile app releases (iOS and Android)

  • 443 API releases

  • 237 modelling backend releases

• 4+ years experience in your main expertise area (Frontend, Backend etc)

• Comfortable picking up new things and working on technologies outside your comfort zone

• Are skilled in delivering features end-to-end, from architecture design and building through to releasing, testing and supporting

• Enthusiasm for our ways of working which include:

  • Iterative development, continuous deployment and test automation

  • Knowledge sharing, pair programming, collaborative design & development

  • Shared code ownership & cross-functional teams

• Have experience with React Native (worked on large scale applications)

• Have experience with AWS

• Are experienced in delivering features full-stack

• Are experienced in SwiftUI

• Are experienced in deployment, releasing cycles or CI/CD

• Have experience with Serverless architectures

• Experience with Terraform or other IaC tooling (e.g. CDK, CloudFormation, etc.)

• Have experience in open source contributions, including reporting bugs/issues in GitHub, testing new releases, or contributing to code

Below you can find a small reflection of our current tech stack:

Frontend:

• React Native (iOS and Android)

• Typescript

• GraphQL (Apollo Client)

• Fastlane

• SwiftUI (Apple Watch)

• Maestro E2E tests

Backend:

• Serverless (AWS)

• Lambdas (NodeJS & Python)

• AWS AppSync

• DynamoDB, S3, SQS, SNS, EventBridge, SageMaker

• Snowflake

All the other good stuff:

• Sentry

• GitHub Actions

• Intercom, Mixpanel

• RevenueCat

• App Store Connect / Play Store

• Google Tag Manager

We’re offering a salary of £90,200-£100,400 per year, depending on experience, plus participation in Strava's long-term incentive (stock) programs.

Overview of our benefits is below:

We’re also committed to continually evolving our benefits to support you as we grow. Here is a brief overview what we currently offer in the UK 🇬🇧

• 🏢 Flexible working – we typically spend 3 days a week together in our Vauxhall office

• 🏝️ 25 days holiday, plus bank holidays (which you can take whenever suits you)

• 📱Free Runna & Strava subscriptions for you and 3 of your friends (get ready to be your friends fave person or save them for holiday presents!)

• 🧡 Strava membership!

• 🧘 Headspace membership

• 💸 Money every year to spend on gear, events and the gym!

• 🤑 We’ll give you a voucher to spend on our website so you can buy yourself new Runna kit (and will renew this every year on your work anniversary)

• 🏥 Private health insurance with Bupa and workplace pension scheme

• 💖 Modern Health ia a mental wellness platform and app that combines technology with professional support to improve mental well-being and reduce stress

• 🥕 Carrot fertility support - this benefits provider can provide inclusive fertility, hormonal health, and family-forming benefits to our global employee population and takes the burden off what we know can be a stressful process.

Please see more info on our amazing benefits here: Benefits at Runna

Our aim is to keep the interview process as straightforward and enjoyable as possible, and will consist of the following stages:

1. Screening call with Talent team (30 minute video call)

2. Getting to Know You + Live Coding (45-minute video call, first 25 mins will be an introductory chat followed by two live coding exercises from https://leetcode.com/)

3. Take home technical task (max 1-2 hours to complete, or if you have something interesting you recently built and would like to showcase then that's perfectly OK)

4. 1.5-hour technical interview (the first half of the call will be used to discuss the take-home technical task from the previous stage and the second half will consist of system design and some general architecture/tech questions)

5. Meet the team (in-person chat with founder(s) and rest of the team)

Please let us know if there’s anything we can do to better accommodate you throughout the interview process - this can be from scheduling interviews around childcare commitments to accessibility requirements. We want you to show your best self in the process, so please speak to your Talent Partner