Mobile Engineer

Bitstack started in 2021 with the goal of democratizing Bitcoin in France. From a simple product that rounds up spare change into Bitcoin, we have grown into a crypto‑native bank serving over 300 000 users. Our mission is to rebuild finance from the ground up, empowering people to achieve financial freedom through a more open and inclusive financial system. We are a small, ambitious team that moves fast, sweats the details, and builds products people truly love. Backed by YC and leading VCs, we are building a product that our users love and are just getting started.

Role

Bitstack’s engineering team builds the technology that powers our mission—a product that people use, trust, and care about. Working in small, cross‑functional squads, you will own features end‑to‑end, collaborate directly with designers and product, and ship features that reach hundreds of thousands of users. You will be placed into one of our four squads—Banking , Savings , Growth , or Platform —based on where you can have the most impact.

What you’ll be doing

• Own features from scoping through to production, shaping the approach, making technical decisions, and seeing them through.
• Work closely with engineers, designers, and product in a fast‑moving, cross‑functional squad.
• Build a well‑tested, performant app that communicates with Bitstack’s backend infrastructure.
• Bring high‑quality, accessible user interfaces to life with an emphasis on polish and user experience.
• Ship reliable, scalable products in a production environment and take accountability for what you build.
• Write tests—unit, integration, and otherwise—and care about code quality throughout.
• Work in a highly compliant financial environment where security and reliability are non‑negotiable.
• Contribute to the broader tech and open source communities.

Tech Stack

• Backend: Go, Python
• Frontend: Flutter, Dart, TypeScript, JavaScript
• Databases: SQL

What we’re looking for

• Native iOS or Android experience is a must—when Flutter hits its limits, you go deeper into the native layer.
• A product‑first mindset—you care about the impact your work has on users, not just how the code is written.
• Strong ownership instincts—you scope, build, and support your work end to end without waiting to be told what to do.
• Experience working in small, cross‑functional teams where you make real decisions.
• Understanding of mobile application lifecycles, software development practices, and integration testing.
• Solid Git workflow knowledge and comfort with automation.
• Clear, direct communication—you can talk through your thinking, take feedback, and push back when you need to.
• Fluent English—French is a bonus.

Interview Process

• Introductory Call (30 min) – an initial conversation with our recruiter to learn more about the role and how we work at Bitstack.
• Engineer Call (30 min) – a discussion with one of our engineers about your experience, mobile app thinking, and a basic architecture question.
• System Design (60 min) – a discussion focused on problem‑solving, communication, and prioritisation to assess technical depth.
• Take Home Task & Task Review Call (60 min) – you complete a practical task, then we review it together and explore your thought process.
• Behavioural Interview (60 min) – a conversation about experiences, decision‑making, and collaboration style, using real‑world scenarios.

Perks & Benefits

• Work from our office in Paris (Bourse) or remotely.
• Flexible working hours.
• One of the best health insurance plans with 100% employer contributions.
• Monthly team activities and bi‑annual offsites.
• Swile meal vouchers.
• Competitive salary based on experience and Bitstack stock options.

Please note: we currently can only hire people who are based in the EU with working rights. If you need sponsorship, we can provide this in France only.

Diversity & Inclusion

We hire talented and passionate people from all kinds of backgrounds, we don’t care about your age or where you studied. If you’re excited about the role but your past experience doesn’t match every bullet point in the job description, we still encourage you to apply. What matters most is that you’re a builder at heart, you share our values, and you’re enthusiastic about our mission.