Staff Engineer - AI Tooling & Platform (SF)

Lightsage, Inc.; San Francisco (CA); On-site; USD 180,000 - 240,000; Full time

Job summary

Lightsage, Inc. in San Francisco invites an early engineering hire to join the founding team.

You will own systems end to end across frontend, backend, infrastructure and data, and work directly with customers to turn their problems into shipped features. You will work on improving recommendation quality, design experiments and benchmarks, build agents that write and re-test documentation, and scale eval and data pipelines for enterprise customers.

Qualifications

• Track record of turning a loosely defined customer or product problem into a shipped solution with minimal direction.
• Strong backend experience building reliable systems that handle production load.
• Hands-on experience shipping quickly with AI coding tools such as Claude Code or Codex.
• Clear thinking about technical trade-offs and written communication.
• Experience with research or running rigorous experiments (LLM evals, benchmarks, or A/B tests) is a plus.
• Experience with Next.js, FastAPI, Supabase or Microsoft Azure is a plus.

Responsibilities

• Own systems end to end across frontend, backend, infrastructure and data.
• Work directly with customers to turn their problems into shipped features.
• Design experiments and benchmarks to measure impact of changes.
• Scale eval and data pipelines for enterprise customers.
• Review all code before it ships.

Skills

Backend development

AI coding tools

Communication

Experimentation

Tools

Next.js

FastAPI

Supabase

Azure

Job description

Lightsage, Inc. in San Francisco invites an early engineering hire to join the founding team.

You will own systems end to end across frontend, backend, infrastructure and data, and work directly with customers to turn their problems into shipped features. You will work on improving recommendation quality, design experiments and benchmarks, build agents that write and re-test documentation, and scale eval and data pipelines for enterprise customers.