Technical Lead, Software Development, Full Stack Developer

We’re on a mission to make migration easy.

We started building Marshmallow in 2017. Since then, we’ve grown from 3 to 700+ people, gained unicorn status, raised ~£140M over three funding rounds, turned profitable, insured millions of drivers and lent millions in car loans.

But we’re only just getting started. Our goal is to become one of the largest financial services providers in the world. Over the next 10 years we’ll grow exponentially, not only by scaling our existing products, but also by building new ones.

To achieve our goals we need incredibly ambitious, commercially driven people who never settle for ‘good enough’. Marshmallowers are hungry for autonomy and ownership, and would rather improve than coast. Everyone raises standards and has an impact, with a focus on collective success over self‑interest.

We’ve created an environment where curious, tenacious people win and grow together. If that sounds motivating, this could be the place for you.

Our engineers are at the heart of the solutions. They work on product builds from start to finish, solving lots of challenges to help us build fast and scale up! Our engineers cover a range of skills across frontend, backend, full stack, iOS and Android, and work alongside designers, data scientists, researchers and product managers within our product teams.

Our product teams include Renewals, Growth and Claims to name a few! Each team sets its own roadmap, owns the build and maintenance of products E2E and actively pushes the codebase forward for scale.

Backend and Infrastructure: Latest Java microservice, Spring Boot with Spring Cloud, Dynamo

DB, Terraform, Docker, AWS Fargate, Datadog, Opslevel, and Team City.

Frontend and Mobile: Type Script, CSS‑in‑JS (Styled Components), React, Redux, Redux Hooks, and other modern state management libraries. Kotlin on Android and Swift on iOS.

Data Analytics / Engineering: SQL, Python, Snowflake, dbt, Airflow & Looker.

AI at Marshmallow: Sierra.ai for conversational AI, Python and Lang Chain for agentic AI solutions, Sage Maker and MLflow for Machine Learning, Cursor and Claude Code for developer productivity.

The Growth team’s mission is to bring Marshmallow motor insurance to as wide an audience as possible. We do this by ensuring we have cover that meets the needs – both mainstream and niche – of a huge range of UK drivers, and by ensuring the value of Marshmallow’s offering is clearly communicated to them. In doing so, we contribute to growing Marshmallow’s customer‑base, and growing our top line and profitability.

You'll be at the heart of Marshmallow's growth efforts, collaborating closely with Product, Data, and our users to deeply understand customer needs, solve challenges across our products, and deliver an inclusive, seamless, and impactful experience that drives business growth!

• Lead engineers within a product team to build scalable, reliable and fault‑tolerant customer flows, including midterm adjustments and cancellations.
• Manage and execute ambiguous technical solutions with appropriate sense of urgency to deliver impact to the business.
• Create and promote efficiency and speed within the team by improving existing solutions and developing new ones.
• Partner with stakeholders to understand requirements, build and deliver functionality iteratively.
• Mentor engineers from Junior to Senior levels of experience, supporting their development through feedback and sharing opportunities.
• Origin and review architectural designs to meet Marshmallow’s growing scale.
• Work closely with the Engineering Manager to champion and roadmap technical debt investment.

• 8+ years of software engineering experience.
• 2+ years of experience as a Technical Lead.
• Strong experience with developing and scaling complex microservices systems.
• Previous experience with identifying, analysing, and resolving system availability, reliability, and performance issues.
• Experience mentoring and guiding engineers with a range of experience.
• Strong expertise in any object‑oriented language, preferably in…