Founding Engineer

Lightsage builds infrastructure for the emerging agent economy, helping organizations track, benchmark, and improve how coding agents discover and use their APIs, CLIs, and MCP integrations. The platform is used by enterprises and high-growth startups to become the default tools recommended by software agents. Lightsage focuses on agent experience and measurable impact on developer and product adoption, with more information available at lightsage.com. The team also created DevToolArena.com, a public benchmark that ranks developer tools across areas like authentication, inference, and voice using Claude Code and Codex. Joining Lightsage offers the opportunity to shape how agent-led growth and developer tooling evolve in a rapidly changing ecosystem.

About the role

As a Founding Engineer at Lightsage, you will design, build, and scale core infrastructure and products that power agent-led growth for developer tools and platforms. You will work closely with the founders to define technical architecture, implement new features, and create benchmarks and analytics that measure how agents interact with APIs, CLIs, and MCPs. Your day-to-day will include writing high-quality production code, building data pipelines and dashboards, integrating with third-party tools, and experimenting with agent frameworks and AI coding systems. You will collaborate directly with customers to understand their needs, refine product requirements, and ship end-to-end solutions from prototype to production.

Responsibilities

• Design, build, and scale core infrastructure and products
• Define technical architecture with founders
• Implement new features
• Create benchmarks and analytics for agent interactions
• Write high-quality production code
• Build data pipelines and dashboards
• Integrate with third-party tools
• Experiment with agent frameworks and AI coding systems
• Collaborate with customers to understand needs and refine requirements
• Ship end-to-end solutions from prototype to production

Requirements

• Able to take a loosely defined customer or product problem and drive it to a working shipped solution
• Prior founder or early-stage startup operator experience is a plus
• Strong written communication and ability to explain technical decisions clearly
• Experience working with Next.js, FastAPI, Supabase, Microsoft Azure

Skills

• Next.js
• FastAPI
• Supabase
• Microsoft Azure
• Agent frameworks and AI coding systems (experimentation)
• Data pipeline and dashboard development
• Customer collaboration and requirement refinement

Pay

Compensation Range: $120K - $200K

Schedule

Full-time, on-site role based in San Francisco, CA