Senior Software Engineer; Freelance - Paris or NY

Senior Fullstack Engineer

At WeWard, we're on a mission to help millions of people live healthier lives through technology. Since launching in 2019, we've grown one of the world's leading walking apps, with more than 30 million users across 29 countries. Today, we're taking the next step:
We're launching a new strategic initiative focused on new products. Our ambition is to build a portfolio of consumer apps built with AI. We're looking for a Senior Fullstack Engineer, to help bring this vision to life. This freelance role exists as we need senior engineering capacity to start prototyping, testing and shipping from rapidly, without lowering the bar on product quality, reliability, and maintainability.

As our first engineer dedicated to this initiative, you'll play a foundational role. You'll become part of the engineering organization led by our future CTO and help establish the technical foundations of this new business. Working directly with Marie-Sophie, Chief of Staff, Yves and Tanguy, WeWard's co-founders, you'll rapidly prototype, test and launch multiple applications over the coming months.

Your responsibilities will include:

• Design, build and launch scalable mobile applications from scratch with AI.
• Own the technical architecture from the very first MVP to production-ready products.
• Develop both backend services and the frontend components required to rapidly ship new products.
• Integrate LLMs, AI APIs and intelligent agents to create delightful user experiences.
• Leverage AI-powered development tools to dramatically accelerate software development.
• Prototype, test and iterate quickly based on user feedback.
• Work closely with Product, Design and the founders to turn ideas into successful products.
• Make technical choices that align with WeWard's existing stack, so that every product launched can be taken over, maintained and evolved by our internal teams.
• Help define the long-term technical foundations of WeWard's new products.

Our commitment s:

• SUCCEED — You'll join a team of passionate people who share values of ambition and determination.
• TRUST — We give you real autonomy, trusting you to reach your goals in your own way.
• EXPLORE — You'll grow in a culture that's constantly evolving and curious about what's next.
• PROGRESS — We'll support you through challenges, learn from mistakes, and move forward together.
• SMILE — And every day, you'll be part of a fun and positive environment where humor is always welcome.

You're the perfect match if…

• You're a builder with a strong product and entrepreneurial mindset.
• You have 7+ years of software engineering experience, with deep expertise in backend development and scalable architectures. You've already built AI-powered applications and naturally leverage AI tools to dramatically increase your development speed.
• You're proficient with Python on the backend, comfortable across the AWS ecosystem, and at ease with React Native, ideally Expo, to build polished cross-platform mobile applications end-to-end.
• You have a strong sense of scalability and know how to assess an existing stack, decide what to keep or evolve, and make pragmatic technical choices that support the broader product ecosystem over time.
• You thrive in fast-paced environments, enjoy shipping quickly, iterating based on user feedback, and taking ownership from architecture to production.
• Beyond your technical skills, you're fluent in English, pragmatic, business-oriented, and excited by the challenge of building new products from scratch.

If this sounds like you, apply — we'd love to meet you.

In Paris:

• A global, mission-driven team with teammates in Paris, NY, London, Boston!
• A healthy work/life balance (we walk the talk)
• Annual learning & dev budget (you grow, we grow)
• Work-Life balance: work remotely up to 2 days per week
• (Really, really) cool office in central Paris with snacks, a walking desk and a huge Wardy hanging around
• ...and so much more!

In NY:

• Top tier earnings: dive into a role offering a competitive salary range, with bonuses and stock options
• Health insurance covered with Aetna (including Dental and Vision)
• Global work culture: at least one visit per year to get chances to work from our Paris office
• Work-Life balance: work remotely up to 2 days per week
• 25 days of PTO + federal holidays
• Commuter benefits: we utilize pre tax dollars that are deducted directly from your paycheck, allowing you to get to work with a little less effort
• 401k Plan: with a 2% employer match, 2 years graded vesting

And if it's a match… Welcome to the adventure!