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 7,000 stars on GitHub, a testament to our active and growing developer community. Next-gen companies such as Mistral.ai, Together.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.

The Role

We’re hiring a Solutions Engineer (Post-Sales) to join our Product team.

This role is focused on helping users implement Lago successfully and ensuring they get long-term value from the product. You’ll work directly with technical and non-technical users post-sale — guiding them through onboarding, supporting their implementation, and helping them adopt Lago in the most effective way for their use case.

You’ll be the technical point of contact for our customers during their onboarding and expansion phases, while also providing structured feedback to the Product and Engineering teams to improve our features and documentation.

This role is based in our Paris office, with a minimum in-office presence of 3 days per week.

Responsibilities

• Lead the onboarding of new users, ensuring they successfully integrate Lago into their stack
• Act as a technical advisor during implementation, helping customers configure the product to fit their architecture and billing logic
• Provide guidance on Lago’s APIs, SDKs, webhooks, and integration patterns
• Identify technical challenges and proactively help resolve them
• Produce and maintain internal and external documentation, playbooks, integration guides, and demo assets
• Partner with Product and Engineering to share structured feedback from users
• Track customer implementation progress and ensure adoption of key features
• Support post-onboarding expansion opportunities with technical enablement

Requirements

• 3+ years experience in Solutions Engineering, Technical Account Management, Customer Success Engineering, or a similar technical post-sales role
• Strong understanding of modern API products, developer workflows, and product-led growth environments
• Ability to work directly with engineering teams to debug issues and recommend solutions
• Excellent communication and collaboration skills across technical and non-technical stakeholders
• Based in or willing to relocate to Paris, with in-office presence at least 3 days a week
• Fluent in English, French is a plus
• Experience in billing, infrastructure, developer tools, or open-source projects is a strong plus

How we work

• Based in Paris, in-office at least 3 days a week
• Written, async-friendly culture
• Direct access to Product and Engineering teams
• Transparent, user-driven roadmap
• Autonomy and ownership from Day 1

Why Join Lago?

• Work on a product loved by engineers and product teams
• Join a lean and ambitious team building foundational infrastructure
• Contribute to an open-source project with real-world impact
• Competitive compensation and early equity in a fast-growing company

Ready to Build with Us?

If you’re excited about joining a high-talent team to solve meaningful problems and help businesses thrive, we’d love to hear from you. Apply today and let’s build something remarkable—together.

• Back-end: Ruby, Postgres, AWS
• Front-end: .js, React, GraphQL, Typescript