Product Engineer (AI Agents for Growth) at Lago

Lago is the leading open-source billing platform for usage-based pricing, powering billing for companies like PayPal, CoreWeave, Mistral AI, and Synthesia (YC S21).

The role involves transforming working AI prototypes into a production-grade multi-agent platform for go-to-market operations. These agents run on Claude Code, connect to CRM, Slack, and email, and have been iteratively refined with real production data over several months.

Key Responsibilities:

Decompose monolithic AI skills into composable agents with clear inputs, outputs, and failure modes — built on Claude Code and Claude Agent SDK

Make the system multi-user with differentiated permissions, views, and triggers with shared state layer

Implement automated feedback loops where system corrections inform agent calibration

Extend to additional workflows (deal automation, risk scoring, competitive monitoring)

Ship production systems with instrumentation and continuous improvement

Required Skills:

Production systems experience with APIs, databases, async workflows, CI/CD

Hands-on LLM development (Python or TypeScript)

Understanding of agent architectures (chains, routers, autonomous agents)

Experience with tool-use APIs, structured outputs, and AI reliability engineering

Product thinking focused on workflows

Nice-to-Have: HubSpot or CRM familiarity, Slack/Gmail API integration, webhook-driven architecture, evaluation/benchmarking frameworks

Salary: EUR 60,000 - 80,000

Location: Remote (France, Spain, Germany, Italy, UK)

Success Metrics:

3 months: First system decomposed, 2+ team members using autonomously

6 months: Self-improvement live, new workflow in production

12 months: Platform core to GTM operations