About Lago

At Lago, we’re on a mission to make billing simpler, more transparent, and more adaptable for SaaS companies.

As the leading open-source billing platform, we empower businesses to build flexible pricing models and scale with confidence. We’ve raised over $22 million in funding from top-tier investors, reflecting strong confidence in our vision and growth.

Our platform has garnered over 8,000 stars on GitHub, a testament to our active and growing developer community. Next-gen companies such as Mistral.ai, Groq, and Laravel chose Lago for their billing.

We’re a team of ambitious, focused individuals who work together to solve hard problems with excellence and accountability. At Lago, we value reliability and proactivity—we trust each other to own tasks, drive them to completion, and adapt quickly. While we encourage you to try fast and “fail fast”, we also expect you to learn fast: make mistakes, but don’t make the same one twice.

If you’re excited by challenges and want to grow alongside a high-performing, supportive team, this is the place for you.

What you’ll do

Contribute daily to all parts of our code base, using our development workflow
Tackle a wide variety of technical problems throughout the stack
Help grow the back-end team
Work with out Product Team, and our Front-end Engineers to understand customer needs and challenges
And come up with technical solutions to create and improve the best features, and our architecture

The ideal candidate will have

Strong knowledge of Ruby (at least 6 years hands-on experience)
Experience working with lots of data and event-driven environments
A genuine passion for Open-Source: if you’ve contributed to OSS projects or used OSS tools, let us know!
Bonus: you’ve worked on billing or tax projects: whether it was to implement a billing system, or maintain it, or integrate it with business tools (e.g., a CRM, Finance tools)
A real appetite for the early stages of co-creating a product and shaping Lago's future

We offer a competitive package including equity for employees based in France, we're remote-friendly, and organize regular workations usually by the ☀️🌊🏄‍♀️

Location: EU (+2h/-2h from Paris) This role is based either in-office in Paris in our gorgeous new office in the 10th arrondissement, and/or remote in a timezone that is +2/-2h from CET.