Full-Stack Engineering Lead

About the role

The Flex is redefining the way people move through the world by treating accommodation as a fluid service rather than a rigid contract. We are building the operating system for modern renting, leveraging AI and automation to remove friction from every step of the journey. This role is for a Full-Stack Engineering Lead who thrives in a fast-moving, product-first environment and is ready to take ownership of critical technical decisions. You will be responsible for architecting the core platform that powers our global operations and directly shaping the engineering culture. Your work will ensure that our technology is robust enough to scale internationally while remaining intuitive for users on the ground. If you are driven by impact and believe software should solve real problems, this is your opportunity to leave a mark.

Key facts

What you'll do

Architect and deliver the core platform components that power The Flex marketplace, ensuring they meet the demands of a global audience.

Lead the design and implementation of scalable backend services using Python and FastAPI to handle high-volume transaction processing.

Translate complex operational requirements from partners and internal stakeholders into reliable technical specifications and product features.

Develop and maintain integrations with third-party systems such as Airbnb, Hostaway, Stripe, Twilio, Google, and OpenAI to create a unified ecosystem.

Implement AI-driven workflows and tooling that enhance pricing, optimize listings, and improve guest communication across multiple markets.

Own the reliability and performance of our infrastructure on AWS, identifying bottlenecks and driving improvements to uptime and scalability.

Define and enforce engineering best practices, including code quality, testing standards, and technical documentation to support long-term growth.

Mentor engineers through hands-on guidance and code reviews, fostering a culture of continuous learning and high performance within the team.

Collaborate closely with product, operations, and revenue teams to turn business constraints into elegant technical solutions.

Build automation frameworks that reduce manual effort and allow our operations to scale seamlessly across an increasing number of cities.

Requirements

Must have extensive full-stack software engineering experience, with a strong track record of delivering production-grade applications.

Must demonstrate a deep understanding of APIs, database design, and cloud infrastructure to build systems that are both robust and efficient.

Must have led technical projects from initial concept through to deployment, ensuring that solutions are delivered on time and to a high standard.

Must possess excellent problem-solving abilities and communication skills to bridge the gap between technical and non-technical stakeholders.

Must show a strong ownership mentality with a bias toward execution, taking responsibility for outcomes rather than just tasks.

Must be comfortable balancing rapid delivery with engineering quality to maintain a sustainable pace of innovation.

Must have experience designing systems that remain scalable, reliable, and maintainable as the company expands internationally.

Must be proficient in the core technologies that underpin our stack, making it easy to learn new tools and lead technical direction.

Nice to have

Prior experience leading engineers or technical teams in a startup or high-growth environment.

Background working with AI products or integrating Large Language Models into production systems.

Experience in SaaS, marketplace, travel, or PropTech businesses, with a clear understanding of their operational models.

Hands-on experience with FastAPI, React, AWS, or Supabase, which aligns closely with our current technology choices.

Practical notes

This is a remote-first role with the flexibility to work from anywhere, though based in Paris.

Travel may be required to support operations or meet partners in key markets from time to time.

This role is not suitable for those who prefer large corporate environments with rigid processes.

About The Flex

The Flex is hiring for Full-Stack Engineering Lead. The listing location is Paris.

This Full-Stack Engineering Lead opening is posted for Paris.