Solutions Engineer (L2 - Post Sales) at Lago (S21) €60K - €90K EUR Open Source Metering and Usage Based Billing Paris / Remote (FR) Full-time US citizenship/visa not required 3+ years 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. About the role Skills: Ruby, Git, SQL 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 also raised over $22 million in funding from top tier investors, reflecting strong investor 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” (if needed), 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. Overview The Solutions Engineer (Level 2) is the bridge between Lago’s technology and its most strategic customers. You are both a product expert and a trusted partner, ensuring that complex issues are not just fixed but understood, communicated, and prevented in the future. While Level 1 engineers ensure SLA compliance and triage, you own the investigation, solution, and customer relationship for more complex or Tier 1 cases. You think systemically, connect dots across product and engineering, and translate technical complexity into customer clarity. This is a hybrid role blending technical troubleshooting, product insight, and relationship management, critical to Lago’s reputation for reliability and customer empathy. What you’ll be doing Act as primary technical contact for Tier 1 customers and complex use cases. Lead the onboarding of Tier 1 customers, both for their Engineering team and their Finance teams Own escalations from L1, reproduce, debug, and define durable solutions in collaboration with Core Engineering. Conduct root cause analyses, document findings, and propose product or process changes to prevent recurrence. Lead proactive initiatives to improve documentation, observability, and internal troubleshooting playbooks. Partner with Product and Engineering to influence roadmap priorities based on recurring customer themes. Build and maintain trusted relationships with customer technical teams; manage communications clearly and confidently during critical incidents. Identify opportunities for expansion, optimization, and proactive configuration improvements within existing accounts. Mentor L1 engineers through technical coaching, shadowing sessions, and QA of complex tickets. Who you are A structured problem solver who can diagnose issues across APIs, integrations, and data flows. An excellent communicator who can simplify complexity for both technical and non-technical stakeholders. Proactive: you don’t wait for issues to escalate; you anticipate and prevent them. Comfortable working directly with engineers, reading logs or code snippets, and proposing technical solutions. Curious about how systems work under the hood and how customer needs evolve over time. Empathetic and composed under pressure, able to guide customers through ambiguity with confidence. Who you’re not You don’t treat customer issues as interruptions, they’re opportunities to improve the system. You don’t deflect ownership or blame; you collaborate, document, and drive progress. You don’t rely solely on engineering to “fix it”; you seek to understand and contribute to the solution. You don’t see support as reactive; you see it as the front line of product improvement. Requirements 4+ years in a technical support, solutions engineering, or customer-facing technical role. Demonstrated experience debugging APIs, data pipelines, or integration workflows. Strong technical literacy in backend systems, SQL, and data analysis tools. Proven ability to lead complex customer investigations end-to-end: from triage to root cause to resolution. Excellent written and verbal communication skills; fluent in English. Strong organizational skills; able to prioritize multiple high-stakes projects in parallel. Evidence of collaboration with engineering and product teams to improve product reliability or scalability. Nice to have Experience with developer tools, SaaS, or API-first products. Familiarity with Git workflows and participating in code reviews or merge requests. Background in data engineering or analytics environments. Experience leading customer post-mortems or technical reviews. Exposure to enterprise account management or solutions architecture. How we work 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. Technology Back-end: Ruby, Postgres, AWS Front-end: .js, React, GraphQL, Typescript