Senior Android Engineer 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.

(Hybrid - 3 days a week in our London Office)

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.

The team you'd be joining

We're looking for a driven and curious senior Android engineer to join the New Financial Products Team as we embark on one of Marshmallow's most ambitious chapters. In 2026, the team is focused on transforming Marshmallow from a car insurance and car finance provider into a high-engagement financial companion for migrants in the UK — and your work will sit at the heart of that mission. This role directly supports our foundational strategic pillar for 2026: building the product and data capabilities that will unlock multi-product growth, deeper customer understanding, and new revenue streams over time.

What you'll be doing

• Join a team operating in new territory for Marshmallow. You'll help define what to build, pivot when priorities shift, and take initiative without waiting to be asked.
• Own significant parts of our Android codebase end-to-end, establishing yourself as the go-to expert for core components and systems while actively raising the technical bar for those around you.
• Shape how we build, not just what we build. You’ll partner with engineering and product leadership to define the technical roadmap and influence architectural decisions that will underpin Marshmallow's next chapter.
• Design and ship high-quality Android solutions using modern practices (Jetpack Compose, MVVM/MVI, Kotlin Coroutines, robust CI/CD) — embracing AI tooling to accelerate development, and writing code that is simple, well-tested, and built to scale.
• Lead medium to large projects across multiple engineers, breaking ambiguous problems into clear milestones and driving delivery with the kind of ownership that others can depend on.
• Drive improvements to tooling, processes, and engineering culture proactively, using data to cut through ambiguity and making the team measurably faster and higher quality over time.

Who are you

• You thrive under pace and know how to make smart trade-offs. You weigh up risk, cut through noise, and keep delivery moving without sacrificing quality.
• You don't wait for problems to come to you. You spot them early, solve them proactively, and bring others along with you.
• You embrace change and actively seek out new tools and approaches to raise the quality and pace of what your team ships.
• You build trusted relationships naturally, working across product, design, and backend teams with a collaborative mindset and a shared sense of ownership over outcomes.
• You bring your engineering perspective into product conversations, using technical insight to challenge assumptions, spot opportunities, and help shape decisions before they become requirements.

What we're looking for from you

• Strong commercial Android development experience, with a strong command of Kotlin and hands-on experience with Jetpack Compose and Kotlin Coroutines.
• A track record of shipping high-quality apps to the App Store and Google Play Store.
• Experience working in cross-functional teams alongside product, design, and fellow engineers to align on objectives and drive outcomes.
• A commitment to writing maintainable, well-tested code that enables safe and efficient development practices.
• Collaborates with designers and Product Managers early and often to influence how ideas take shape, ensuring decisions are grounded in real-world mobile constraints and user experience.

Our Tech Stack

• All new features are built in Kotlin, Jetpack Compose and Coroutines.
• Access to Claude Code to help engineers move faster on boilerplate, debugging, and code review.
• Code is organised into local Gradle feature modules to help keep it maintainable and scalable.
• We use automation as much as possible when it comes to testing our app, writing unit tests for business logic, snapshot tests for UI and automated UI tests for user interaction.
• Our continuous integration tool of choice is Bitrise.
• We review each other's code using GitHub and automate as much of our code styling as possible using tools like lint and detekt.
• We are committed to fostering the professional growth of our team members and are open to coaching Android engineers who are interested in expanding their skill sets in backend or full stack technologies. We believe in providing a supportive environment where continuous learning is encouraged, and we are happy to facilitate training and mentorship opportunities to help you achieve your career goals.

Perks of the job

• Bonus scheme designed to reward high performance.
• Private medical insurance with Vitality, mental health support with Oliva.
• Personal learning budget and 2 dedicated L&D days a year.
• Monthly flexible benefits budget to spend as you choose.
• 25 days holiday plus bank holidays.
• 4 weeks Work From Anywhere per year.

Our process

• Initial call with a member from our Talent Team (30 mins).
• Past Experience interview with Hiring Manager & GM of New Financial Products (30-45 mins).
• Android technical skills case study and interview with a couple of the team (120 mins).
• Culture interview (60 mins).

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.

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.