Open Source Metering and Usage Based Billing

Sr Back-end Ruby Engineer

$50K - $100K
Paris / Bogota, CO / Remote (Bogota, CO; FR)
Job Type
6+ years
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About the role

The team and your role

We're a team of 10 today, and we're all about Product, FinTech and Open Source.

Our Product is really tech-driven, as we process and structure a lot of data, and build for developers so we have numerous exciting back-end challenges!

Your role includes:

  • Contribute daily to all parts of our code base, using our development workflow
  • Tackle a wide variety of technical problems throughout the stack
  • You will also have to help grow the back-end team

You will also work with out Product Team, and our Front-end Engineers to:

  • Understand customer needs and challenges
  • Come up with technical solutions to create and improve the best features, and our architecture

The person we are looking for

  • Strong knowledge of Ruby (at least 5 years of 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 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

Competitive package including equity ; Remote-friendly ; Regular workations, usually by the ☀️🌊🏄‍♀️

About the interview

Our typical process

  • 20-min first call
  • Technical case
  • Review of the case with the team
  • Offer

What we commit to

  • Your time is precious, and we'll do our very best to be time-conscious with yours.
  • If you're open to it, we commit to give you the most constructive feedback as possible on your case, as we are aware it's quite an investment of time on your side.
  • We approach recruiting as a 2-way street, we make offers when we have a strong conviction on the mutual fit: in terms of skills, mindset, cultural fit.

About Lago

We're the open-source billing API for usage-based, subscription-based, and all the nuances of pricing in between. With Lago, you can make your billing fit your pricing and business workflows, not the other way around.

Our Story

We built a custom billing system from scratch for, a 5x Fintech unicorn in Europe. That was not the best use of our engineers' time (it's complex to build and to maintain), but we felt 'trapped':

  • We did not want to hack around Stripe Billing, or Chargebee, or any of the equivalents to customize it: our pricing was a mix of subscription-based and usage-based, and the existing tools were built for subscription-based businesses
  • We did not want to leave precious % of revenue on the table. We resented their rent-seeker approach, and their closed architecture in general, with data being locked in another product. So we went for a home-made billing system, which was far from being perfect.

Lago aims at fixing this problem at scale, with an open architecture by design.

Our Mission

Lago is on a mission to pioneer a ‘Modern Pricing Stack’*, for Product Led companies.

  • Pricing and all its components (billing, payments, invoicing, cash collection, etc.) are one of the most critical business pillars, and are yet to be systemized.
  • Billing and pricing questions are still one of the most common sources of customer support tickets, and that’s only the tip of the iceberg.
  • Incumbent pricing tools have been built around a “closed architecture” mindset: keeping critical data locked to claim to be the “source of truth”, closing numerous parts of their APIs, only integrating with specific partners to lock you in (e.g., Stripe Billing only working with Stripe Payments), to finally collect a rent-seeker tax on transactions (0.5-1% of revenues). We believe in a more open pricing stack, that interconnects with the company’s internal workflows and systems, with a fairer revenue model.

'* inspired by the ‘Modern Data Stack’ movement (read more here:

Our Values

  • Ambition: we aim big, because otherwise, where is the fun?
  • Progress: we care more about the grit, the steep learning curve, the resilience and creativity muscles, than the current status or where you come from.
  • Humble confidence: we know our strengths and always strive for excellence, but we also know there’s so much we don’t know yet
  • Pay it forward: we’ve all started somewhere, people gave us a hand when we needed one, we don’t forget this, and reinforce this positive cycle
  • Not taking ourselves too seriously: we are ambitious, restless learners and hustlers, but at the end of the day, our health (physical and mental), and our loved ones are what matter the most.
Team Size:9
Location:Paris, France