Lead Backend Engineer (Typescript) in London

Lead Backend Engineer (Typescript) in London

London Full-Time 60000 - 80000 £ / year (est.) No working from home possible
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At a Glance

  • Tasks: Lead the design and development of our customer communication platform using cutting-edge technologies.
  • Company: Join a dynamic team at On, a leading running brand with a collaborative culture.
  • Benefits: Enjoy competitive salary, health benefits, and opportunities for professional growth.
  • Other info: Be part of a fast-paced, diverse team with excellent career advancement opportunities.
  • Why this job: Make a real impact by shaping innovative solutions that enhance customer experiences.
  • Qualifications: 8+ years in backend engineering, fluent in Ruby and Node.js, with strong API design skills.

The predicted salary is between 60000 - 80000 £ per year.

Our Direct to Consumer business is performing and growing strongly, which is why we - within the Customer Communication Platform team in Commercial Technology at On - are looking for a Lead/Senior Backend Engineer to scale On’s online business to the next level.

Our newly created team is focused on providing a customer communication platform product.

As an experienced engineer, you will be responsible to design, build, deploy, test and operate our digital services.

You will be working in our office in London and collaborating closely with the cross‑functional teams across locations.

  • Your Mission
  • You will shape and evolve the customer communication platform by providing APIs, real‑time events and documentation to reduce the cognitive load and enable multiple stream‑aligned teams to rapidly deliver premium, personalized experiences across all consumer touch points.
  • You will lead the design and rollout of complex systems, guide architectural decisions across teams through RFCs, and ensure our platforms are built for long‑term growth and operational excellence.
  • You will act as an expert in the given technology area, leverage best in class engineering practices including continuous integration and deployment, code reviews, high test coverage and allowing for observability.
  • You will iteratively deliver high‑value, high‑quality solutions while balancing speed, scalability, and reliability.
  • You collaborate effectively across diverse teams and stakeholders, driving alignment between product, design, and engineering.
  • You will engage in the engineering community by sharing knowledge, mentoring your teammates, receiving / providing feedback or growing our team by supporting the hiring.
  • You act as a mentor and technical reference for senior engineers, fostering a culture of learning and growth.
  • Your story
  • You have 8+ years of backend experience designing, building, testing, releasing, maintaining, scaling, and evolving complex distributed systems with a strong problem‑solving mindset striving for excellence and taking full accountability across teams.
  • You are fluent in Ruby and Node. js (Type Script and Nest JS as a plus) ecosystems and experienced with API design (Graph QL/REST).
  • You bring strong experience with event‑driven systems (Kafka, Rabbit MQ or similar), distributed data architectures and delivering resilient, observable APIs (New Relic).
  • You have mastered automated testing, TDD, and performance debugging tools, you are hands‑on with operating the infrastructure on AWS or GCP and container orchestration (Kubernetes).
  • You have led architectural initiatives, guided system design through RFCs, and influenced engineering strategy beyond your immediate team.
  • You lead and coach teams through incident response, root cause analysis, and long‑term reliability improvements.
  • You communicate with clarity and empathy, guiding stakeholders through complex trade‑offs and aligning multiple teams around shared goals.
  • You mentor engineers and influence organizational culture, creating an environment of feedback, growth, shared accountability, and technical excellence.
  • You think product‑first — connecting technical decisions to customer and business outcomes, applying holistic thinking and delivering for impact using experimentation.

Attributes of a successful candidate

  • Action‑Oriented: Anticipates opportunities that advance organizational goals and mobilizes others to act with urgency and clarity.
  • Organization‑focused: Builds trusted relationships across teams, creating alignment and shared purpose.
  • Alignment‑driving: Connects technical decisions to organizational strategy and ensures consistent execution across domains.
  • Leads through Ambiguity: Provides clarity and confidence across teams in uncertain or high‑pressure situations.
  • Develops Others and Self: Models continuous learning while fostering growth across the organization through mentoring, coaching, and structured feedback.
  • About the Team

As you might expect from a running brand, the wider E‑Commerce team at On is a fast‑paced place to be.

You will work in the diverse Customer platform team as part of Commercial Technology.

You will collaborate with roles including Software Engineers, QA Engineers, Product Managers, Data Analytics, Marketing and others of stream‑aligned or platform teams that are located in Berlin, Zurich and London.

On is an Equal Opportunity Employer.

We are committed to creating a work environment that is fair and inclusive, where all decisions related to recruitment, advancement, and retention are free of discrimination.

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Contact Details:

On-Ag-5 Recruitment Team

StudySmarter Expert Advice🤫

We think this is how you could land Lead Backend Engineer (Typescript) in London

Join Local Tech Meetups

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Contribute to Open Source Projects

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Tap into Online Developer Communities

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Explore Job Boards Specifically for Tech Roles

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We think you need these skills to ace Lead Backend Engineer (Typescript) in London

Backend Development
Typescript
Node.js
Ruby
API Design
GraphQL
REST

Some tips for your application 🫡

Show off your coding skills:When applying for a software engineering role, it's super important to showcase your coding skills. Make sure your CV includes your tech stack, any relevant programming languages you’re comfortable with, and examples of projects you've worked on. If you have a GitHub profile, link it up! We love to see code in action.

Tailor your portfolio:For a full-time role, we’d expect to see some solid examples of your work in your portfolio. Make sure to include at least two or three projects that highlight your problem-solving skills and your ability to work with different technologies. Focus on the projects that are most relevant to the position at On-Ag-5.

Craft a killer cover letter:Your cover letter is your chance to stand out—make it personal! Explain why you want to work at On-Ag-5 and how your skills align with the role. Show us your passion for software development. We dig enthusiastic candidates who understand the value of collaboration and continuous learning!

Be clear and concise:When it comes to writing your CV and cover letter, clarity is key. Avoid jargon that could confuse us and stick to simple, direct language. Highlight your achievements with quantifiable results where possible, and keep everything easy to read. A well-organised application goes a long way!

How to prepare for a job interview at On-Ag-5

Brush Up on Your Coding Skills

For a full-time software engineering role, it's crucial that we stay sharp with our coding abilities. Expect technical questions that might involve solving problems on the spot or discussing algorithms. Practise on platforms like LeetCode or HackerRank to get comfortable with the types of questions that often come up.

Know Your Tools and Frameworks

Make sure we’re well-acquainted with the tools and technologies listed in the job description. Familiarise ourselves with any specific frameworks or programming languages mentioned. If On-Ag-5 uses React or Node.js, for instance, be ready to discuss how we’ve used them in previous projects or coursework.

Showcase Your Projects

Bring along a portfolio that highlights our best work. This could be code samples, GitHub repositories, or any side projects we’ve built. Make sure we can talk through our thought process for each project, especially the challenges we faced and how we solved them—this shows our problem-solving skills in action.

Prepare for Behavioural Questions

While technical skills are key, full-time positions also require cultural fit. Be ready to discuss our previous experiences and how we handle teamwork, conflict, and deadlines. Brush up on the STAR method—Situation, Task, Action, Result—to clearly articulate our past experiences when discussing how we've contributed to a team.