Staff Full Stack Engineer

Staff Full Stack Engineer

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 2024 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’re looking for a Staff Full Stack Engineer to play a pivotal role in driving the technical success of the [Employer hidden — view at passion-project.co.uk] app. This is a hands-on role, within our App Team, where you’ll work across multiple squads, providing architectural direction, ensuring engineering excellence, and enabling the successful delivery of features across our iOS (React-Native), Android (React-Native), and Apple Watch apps, as well as third-party integrations (Garmin, Strava, Coros, Fitbit, Suunto, etc). 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.

You’ll be a multiplier for the engineering team—mentoring developers, improving processes, and guiding the evolution of our systems as we scale. We’re looking for someone who is not only technically excellent, but also a creative problem solver and collaborative leader who brings energy and clarity to fast-paced environments.ca

• Lead the architectural design and technical strategy across multiple product teams, ensuring scalable, secure, and maintainable solutions.
• Drive the end-to-end delivery of key initiatives, working hands-on to build, test, and ship features across the full stack (mobile, backend, integrations).
• Coach and support engineers by providing technical guidance, mentorship, and code reviews without creating bottlenecks.
• Collaborate with Product, Design, and Engineering Leads to define the best solutions for user experience, balancing speed, quality, and long-term technical goals.
• Champion developer productivity by improving our CI/CD pipeline, tooling, and internal workflows to accelerate delivery and reduce friction.
• Own the release process and support a culture of reliable, continuous deployment—while enabling teams to ship confidently and independently.
• Maintain and grow a high-performing engineering culture based on ownership, knowledge-sharing, and continuous improvement.

5+ years of professional experience in software engineering, with a focus on technical leadership and driving projects end-to-end.

Deep expertise in TypeScript/JavaScript, with a strong foundation across the full stack.

Proven track record of leading the architecture and successful delivery of large-scale React-Native mobile applications in a production environment.

Experience working in AWS cloud environments, with a strong preference for familiarity with serverless architectures (e.g. Lambda, API Gateway, DynamoDB, AppSync).

Skilled in defining and delivering features from initial architecture and design through to release, testing, and production support.

Comfortable stepping outside your core expertise to solve problems across the stack, from frontend to cloud infrastructure.

Able to thrive in a highly skilled, fast-paced engineering team. In 2025, we shipped:

99 mobile app releases (iOS and Android)

443 API releases

237 modelling backend releases

Proven ability to mentor engineers, support team growth, and guide complex projects from design to release.

A proactive advocate for modern engineering practices, including:

• Iterative development, continuous deployment, and test automation
• Knowledge sharing, pair programming, and collaborative design & development
• Shared code ownership and cross-functional product team collaboration

Experience with React Native at scale in performance-sensitive or offline-first applications.

Comfortable with Infrastructure as Code tooling like Terraform, CDK, or CloudFormation.

Able to thrive in autonomous roles, taking ownership without heavy direction.

Have hands-on experience with SwiftUI or native mobile development.

Are confident working with and improving CI/CD pipelines, release cycles, and deployment processes.

Have contributed to open-source communities—through code, issues, testing, or documentation.

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

We’re offering a salary of £108,700-£121,000 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)

[Employer hidden] subscriptions for you and 5 of your friends (get ready to be your friends fave person or save them for xmas 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 [Employer hidden] 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 [Employer hidden]

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

Screening call with Talent team (30 minute video call)

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

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)

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)

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.

Please apply through this link (this will take you to our Ashby career hub). Please note, we are unable to accept any applications outside of Ashby. If you have any questions regarding the status of your application, please email [contact hidden]

Still have questions or want to know more? Check out our Careers Page ✨