Support Engineer

Lago; Paris; Sur place; EUR 65 000 - 90 000; Plein temps

Résumé du poste

Lago is hiring a Support Engineer to join the Product team. This backend role focuses on production-grade problem solving for real users, acting as the technical first responder for product and infrastructure issues, and contributing code or fixes where necessary.

You will bridge user success and product reliability, writing code, reviewing logs, running local instances, and helping move the product forward with real-world use.

Qualifications

• 3+ years of backend experience in infrastructure, billing, or API-heavy products.
• Strong ability to debug production systems from stack traces to SQL queries and logs.
• Experience with REST APIs, authentication flows, webhooks, and asynchronous jobs.

Responsabilités

• Investigate, debug, and resolve technically complex support cases from users running Lago in production
• Reproduce issues locally, inspect logs and database state, and propose or apply code fixes as needed
• Contribute directly to the Lago codebase (Ruby, PostgreSQL, Sidekiq) to resolve bugs and improve reliability
• Write internal tools, diagnostics, or scripts that improve the support workflow and user troubleshooting
• Improve system resiliency based on user feedback and incident patterns
• Maintain and improve support documentation, runbooks, and postmortems
• Collaborate with Product and Engineering on prioritizing bug fixes and technical debt

Connaissances

Backend engineering

Debugging production

REST APIs

Technical documentation

Communication

Outils

Ruby on Rails

PostgreSQL

Sidekiq

Redis

Description du poste

About LagoLago is the open-source platform that helps engineers build better monetization systems. They enable software teams to build customizable and scalable usage metering, subscription management, billing, invoicing, and payment systems. Lago is the leader of their category on Github (5k+ stars), won "Product of the month" on ProductHunt, and is used by leading companies such as Mistral, Together, Swan, Juni, Fintecture, JuliaHub, Regate, Flipside Crypto, Unifonic, Vida.id , Bureau.id, Sortium. Lago's founding team had previously built and scaled the home-grown monetization system of fintech unicorn Qonto from pre-launch to series D.

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

About the roleWe're hiring a Support Engineer to join our Product team. This is a backend engineering role focused on production-grade problem solving for real users. You'll act as the technical first responder for product and infrastructure issues - working with engineers using Lago in complex environments, reproducing and debugging issues at the source code level, and contributing code or fixes where necessary. You'll bridge user success and product reliability: part engineer, part investigator, and part maintainer. This is not a triage role - you'll be writing code, reviewing logs, running local instances, reading database states, and helping move the product forward through real-world use.

Responsibilities

• Investigate, debug, and resolve technically complex support cases from users running Lago in production
• Reproduce issues locally, inspect logs and database state, and propose or apply code fixes as needed
• Contribute directly to the Lago codebase (Ruby, PostgreSQL, Sidekiq) to resolve bugs, close edge cases, or improve reliability
• Write internal tools, diagnostics, or scripts that improve the support workflow and user troubleshooting
• Improve the resiliency of the system based on user feedback and incident patterns
• Maintain and improve support documentation, debug runbooks, and postmortem processes
• Collaborate closely with Product and Engineering on prioritizing bug fixes and technical debt surfaced through support

Requirements

• 3+ years of experience as a backend engineer, ideally in infrastructure, billing, or API-heavy products
• Strong experience with Ruby on Rails , PostgreSQL , Sidekiq , and Redis
• Skilled in debugging production systems - from stack traces to SQL queries to logs
• Comfortable navigating large codebases and contributing meaningful patches
• Understanding of REST APIs, authentication flows, webhooks, and asynchronous jobs
• Excellent written communication and technical documentation skills
• Located in European time zones
• Bonus: experience working with open-source developer tooling or supporting self-hosted deployments

Tech stack

• Ruby
• Payments
• Ruby on Rails