Mobile Engineer

About Bitstack

It all started with an idea in 2021. Initially built to democratize Bitcoin in France, Bitstack has gone from a simple product that invests spare change in bitcoin, to a crypto-native bank bringing a better way to save, spend, and grow money to our 300K+ users. We want to rebuild finance from the ground up to empower people to achieve financial freedom by participating in a more open and inclusive financial system. We’re a small, ambitious team of operators. We believe in moving fast, sweating the details, and creating products people truly love. At Bitstack, you’ll have the opportunity to shape not just our products, but the culture and practices of our entire organization. Bitstack is backed by YC, leading VCs like 13books Capital, Stillmark, Serena, and many more. We are building a product our users love and we are just getting started!

The Role

Bitstack's engineering team builds the technology that powers our mission - a product that people actually use, trust, and care about. We work in small, cross-functional squads with real ownership and short feedback loops. As a mobile engineer, you'll own features end to end, work directly with designers and product, and ship things that land in the hands of hundreds of thousands of users.

We work across four squads - Banking, Savings, Growth, and Platform. You'll be placed into a squad based on your strengths and where you can have the most impact.

What You'll Be Doing

• Own features from scoping through to production - you'll shape the approach, make the technical decisions, and see it 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 know how to 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've had to 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

1. Introductory Call (30 min)
   An initial conversation with our recruiter to get to know you better and share more details about the role, the team, and how we work at Bitstack

2. Engineer Call (30 min)

   A chat with one of our engineers to go a bit deeper into your experience at a high level, find out a bit more about how you think about mobile apps, as well as a basic question around architecture. You will also have a chance to find out more about our engineering culture.

3. System Design (60 min)
   A discussion focused on how you approach problem-solving, communicate your ideas, and prioritise decisions. This helps us assess your technical depth and ability to design scalable systems

4. Take Home Task & Task Review Call (60 min)
   You’ll receive a practical task to complete in your own time. Once submitted, we’ll schedule a review call to walk through your solution together and explore your thought process in more detail

5. Behavioural Interview (60 min)
   A conversation centered on your experiences, decision-making, and collaboration style. We’ll discuss real-world scenarios to understand how you navigate technical challenges, teamwork, and stakeholder interactions.

Perks & Benefits

🌎 Work from our office in Paris (Bourse) or Remote

🕑 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 & 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.

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