Senior Software Engineer I (Full-Stack)

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. 🚀

Who we're looking for

We're looking for a talented, high-quality full-stack engineer to join our team.

We care about how well you build software, how you work within a team, and how fast you learn. Runna's stack and problems will keep changing as we grow, so we're looking for strong engineers who pick up new systems quickly and bring good judgement wherever they land, not a checklist match against today's tech.

You'll work closely with your Engineering Manager and a cross-functional squad - product, design and fellow engineers - as well as colleagues across Strava. Wherever you land, the goal is the same: helping Runna become the most trusted training platform for runners everywhere.

We follow a flexible hybrid model that translates to more than half of your time on-site - 3 days per week in Runna's office based in London, UK.

What you'll be doing

• Architect, build, test and deliver features and reliability improvements across the full stack, from our mobile apps through to the systems behind them

• Take ownership of problems end-to-end, from design through build, release, testing and support

• Work closely with Product and Design to find the most reliable and intuitive solution to the problem in front of you

• Help evolve our developer tooling, CI/CD pipeline and engineering standards, and take your turn in the team's release rotation

• Be on hand to support teammates on tricky technical problems, wherever they sit in the stack

• As you settle in, you'll could dig into things like our recording and sync pipeline, third-party wearable integrations, or interfacing with modelling engineers on plan adaptations - the specifics will evolve with our roadmap and your strengths, so treat this as a flavour of the work rather than a fixed brief

Requirements

If you don't tick every box below, please apply anyway. Research shows that strong candidates can rule themselves out over a partial match even when they'd do the job well. If you're a strong full-stack engineer keen to learn, we'd rather hear from you than not, and we're happy to talk about whether a different role or level might be a better fit.

What you’ll bring

• You're a strong full-stack engineer (frontend or backend-leaning is fine) with a track record of shipping features end-to-end

• You pick up new languages, frameworks and systems quickly, and you're comfortable working outside your current comfort zone as our roadmap evolves

• You care about the craft, writing readable and well-tested code, and have good judgement about when to move fast and when to slow down

• You enjoy working closely with product, design and other engineers to find the best solution to a problem, not just the most technically interesting one

• You take the initiative and look to impact beyond your immediate team, such as improving developer experience or AI-enablement

Our stack today

We hire for general strength, not stack familiarity - most of our engineers joined without prior experience in one or more of the above, and we'll get you fully ramped up during onboarding.

• Frontend: React Native, TypeScript, GraphQL

• Backend: serverless on AWS, Node.js/Python, DynamoDB, Snowflake

• Tooling (continuously re-evaluated): Claude Code, Cursor, Linear with agents, Github with GHA

Nice to have, not required

• Experience with native mobile development (Swift, Kotlin, SwiftUI, watchOS) - useful given how close some of our hardest problems sit to the OS, but not a dealbreaker if you don't have it yet

• Experience with infrastructure-as-code (Terraform, CDK, CloudFormation) or serverless architectures

• Open-source contributions, big or small

• A strong interest in health or fitness technology

We follow a flexible hybrid model that translates to more than half of your time on-site – 3 days per week in Runna's office based in London, UK.

Salary and Benefits

We’re offering a salary of £70,125 - £78,375 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

• 📱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!)

• 🧘 Headspace membership

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

• 🏥 Private health insurance with Bupa and workplace pension scheme

• 💖Modern Health is 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 Interview Process:

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