Technical Lead in London

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.

Engineering at Marshmallow

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.

Our Tech Stack

• Backend and Infrastructure: Latest Java microservice, Spring Boot with Spring Cloud, DynamoDB, Terraform, Docker, AWS Fargate, Datadog, Opslevel, and TeamCity.
• Frontend and Mobile: TypeScript, 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 LangChain for agentic AI solutions, SageMaker and MLflow for Machine Learning, Cursor and Claude Code for developer productivity.

About the Growth Team you’ll be joining

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!

What you’ll be doing

• 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.

What we’re looking for from you

• 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 Java, and a desire to learn more.

Perks of the job

• Flexible working: Spend 3 days a week with your team in our new collaborative London office.
• Sabbatical Leave: Get a 4‑week fully paid sabbatical after being with us for 4 years.
• Work From Anywhere: 4 weeks of work from anywhere to use, with no need to come to the office.
• Competitive bonus scheme: designed to reward and recognise high performance.
• Flexible benefits budget: £50 per month to spend on a Ben Mastercard meaning you get your own benefits budget to spend on things you want, whether that’s subscriptions, night classes, the big shop or a forest of houseplants.
• Learning and development: Personal budget for books and training courses to help you grow in your role and 2 learning days a year.
• Mental wellbeing support: Access therapy and mental health sessions through Oliva.
• Private health care: Enjoy all the benefits Vitality has to offer, including reduced gym memberships and discounts on smartwatches.
• Medical cash plan: To help you with the costs of dental, optical and physio.
• Tech scheme: Get the latest tech for less.
• Plus all the rest; 33 days holiday (including bank holidays), pension, cycle to work scheme, monthly team socials and company‑wide socials every month!

Our process

We break it up into 3 stages:

• Initial call with Tech Talent Acquisition team (30/45 minutes).
• Tech interview with two engineers which is centred around pair programming, systems design and operational excellence questions (1 hour 30 minutes).
• A past experience & culture interview with one of our engineering managers to check that your ways of working aligns with our processes, mission and values (1 hour 30 minutes).

We’ll let you know if you’re invited to an interview or not. But, as a small team with a lot of applications to consider, we can’t give individual feedback on each application.

Background checks

As part of our commitment to maintaining a safe and trustworthy environment, we’ll carry out standard background checks, including a DBS and a Cifas check. These help ensure there are no ongoing criminal proceedings and support the prevention of fraud and other forms of serious misconduct. If anything of concern is identified, it may affect your eligibility for certain roles or services. Feel free to ask our Talent Acquisition team if you have any questions about this!

Diversity of thought

We know the best ideas come from having different perspectives in the room - and we're committed to hiring fairly, regardless of background, identity or experience. If you see yourself in this role, we'd encourage you to apply.