Software Engineer ($180K - $220K + Equity) at YC-backed AI Data Infrastructure Startup

About the job

Job Title: Software Engineer

Salary: $180K – $220K + competitive equity

Company Description: YC W25 AI data infrastructure startup, SF, 8-figure revenue, just announced Series A

Job Description: Join a 20-person YC company that is pushing the frontier of LLMs and AI agents through novel datasets and infrastructure. They work with all 5 leading AI labs and are becoming the go-to data infrastructure partner across the AI ecosystem. As a Software Engineer here, you will have end-to-end ownership over projects that are genuinely hard and non-commodity. One week you might prototype a new RL environment from a research paper, the next you are deploying distributed experiments on Kubernetes, and the week after you are improving the reliability of a Next.js dashboard or building a Kafka pipeline for annotator analytics. Sharp hockey-stick revenue growth, a talent-dense founding team, and a just-announced Series A mean this is one of the most exciting early bets in AI infrastructure right now.

Why this role is remarkable:

• Work on frontier AI data infrastructure used by every major AI lab in the world, on problems that are hard by design and critical to how next-generation models are built
• Join at the Series A with a founding team that has built high-bar teams before, coming from Citadel Securities, Goldman Sachs, and top PE firms
• Own your work end-to-end from day one at a company growing faster than almost anything else in AI right now



What you will do:

• Build and ship fullstack systems across a modern stack including Next.js, React, Python, Kubernetes, Kafka, and Redis with real end-to-end ownership
• Work directly with AI lab researchers as a client-facing engineer on the infrastructure that powers frontier model training and evaluation
• Break down ambiguous, hard problems and deliver production-grade solutions in a fast-moving, high-trust environment

The ideal candidate:

• 1 to 3 years of fullstack engineering experience from a high-growth VC-backed startup, a top quantitative trading firm, or a company in the human data and AI annotation space, with a degree from a top-30 school
• Strong fullstack ability with a bias toward ownership, clear signals of excellence in background and work, and the kind of curiosity that makes hard infrastructure problems exciting rather than overwhelming
• Based in SF or ready to relocate, willing to work 5 days a week, and excited about being close to the hardest problems in AI

Next steps

1. Apply via this LinkedIn job post
2. We’ll review and reach out if there’s a strong match
3. If aligned, we’ll introduce you directly to the team

If this role isn’t the right fit, we may suggest and make introductions to other high-signal startup roles we’re recruiting for – always with your permission.

A quick note on authenticity

This is a real, active role we’re supporting in partnership with the hiring team. We don’t post speculative roles and work closely with teams on their actual hiring needs.