Founding Engineer, Full-Stack

About Orthogonal

Orthogonal (YC W26) is building the infrastructure layer for AI agents to discover, access, and pay for APIs. We're starting with go-to-market, the APIs that power outbound, enrichment, and growth. We're two technical cofounders in San Francisco.

The Role

This is a founding role, not a maintain-the-codebase role. You'll ship end-to-end across our whole stack — Next.js frontend, TypeScript/Postgres backend, and the SDK/CLI/MCP tooling — owning features from idea to production and helping set our engineering direction. You'll work directly with both founders.

What you'll do

• Own features end-to-end across the frontend (Next.js) and backend
• Build API integrations, developer tooling (SDK, CLI, MCP server), and core platform features
• Move fluidly between frontend polish and backend systems as the work demands
• Ship to production constantly; use AI tools heavily to build, debug, and iterate
• Help shape architecture and engineering culture as one of our first hires

Who you are

• Strong generalist with a track record of shipping full-stack products
• Fluent across Next.js/React, TypeScript, and Postgres
• Bias to action, you ship and iterate rather than over-plan
• Comfortable owning ambiguous problems on a small team
• Genuinely excited about AI agents, APIs, and developer tools

Nice to have

• Built and shipped your own products or startups
• Experience with developer tooling or API design
• Familiarity with AI agents, MCP, or LLM tooling
• Open source contributions

Details