Founding Product Engineer (Full-stack) at Relixir (X25)
$250K - $300K  •  0.25% - 1.00%
GEO-Native CMS
San Francisco, CA, US
Full-time
US citizen/visa only
1+ years
About Relixir

Relixir is the content DB for AI search, helping 40+ B2B companies create and serve content for LLMs. We're Berkeley alums and one of the fastest growing companies from YC X25 batch.

About the role
Skills: Next.js, Python, TypeScript

Role: Founding Product Engineer (Full-stack)

Location: In-person, SF

Stack: Next.js, TypeScript, FastAPI, PostgreSQL, AWS (ECS, Fargate), LLM APIs

What You’ll Work On

Frontend Platform:

  • Architect and ship core product surfaces with Next.js + Typescript
  • Design and implement high quality user experiences for complex state / data patterns
  • Deliver fast and clear data visualizations for millions of data points from various sources

 

Backend Infrastructure:

  • Building features in Python (FastAPI) with PostgreSQL as our primary database.
  • Managing AWS infrastructure — primarily ECS/Fargate, Lambda, S3, and related services.
  • Designing APIs for the frontend (TypeScript) and partner integrations.
  • Working on AI (LLM-powered) features end-to-end

The ROLE

You are not just an employee – you are a builder of the company.

You’ll be at the core of shaping Relixir’s product, technology, and trajectory – from hands-on full-stack development, to collaborating on the big decisions that define our future.

  • Strategic Impact – Work directly with the founders to influence technical and product direction, deciding how we scale our platform and what bets we make in AI search automation.
  • End-to-End Ownership – Take ideas from rough concepts to production-ready systems – UI/UX, frontend components, APIs, LLM usage, and everything in between. You’ll own critical features and ensure they’re fast, reliable, and a joy to use.
  • Customer-Driven Development – Talk to customers, dig into their needs, and turn feedback into technical solutions that directly impact their growth.

About You

  • Deeply Curious — You actively seek to understand complex systems, customer problems, and the latest technical possibilities. Curiosity drives your best work.
  • Relentlessly Driven — You thrive in early-stage chaos. You move quickly, test bold ideas, and turn uncertainty into working solutions.
  • True Owner — You don’t just “complete tickets.” You take full responsibility for delivering outcomes — finding a path forward even with incomplete information.
  • Collaborative & Humble — You share ideas openly, listen actively, and care more about the best solution than being right. You’re confident in your skills but always learning.

Must-Haves

  • In-person SF
  • High-agency
  • 1-3+ years of experience building frontend & backend software for VC-backed startups
  • Leveraged LLMs for building critical product features
  • Strong proficiency in Next.js, Typescript, and Python
  • Have completed at least one 0 -> 1 journey of a functional product

Nice-to-haves:

  • Entrepreneurial Mindset: Ex-founder or future founder
  • AWS Infrastructure Management 
  • Timescaledb or any OLAP experience
  • Qdrant/RAG, LangChain/LLM tooling, prompt/eval experience.

Why This Role is Special

  • You’ll be part of the founding team — shaping the product, culture, and technical foundation of a YC-backed startup already working with 50+ enterprise customers.
  • You’ll have ownership — own UI/UX quality, API/DB design, and performance end-to-end. Shipping features that surface insights and actions from millions of AI-search data points each week.

Technology

Python, Typescript, Docker, FastAPI, PostgreSQL, AWS, OpenAI

Interview Process
  1. Intro call with founders (15-30 min)
  2. Technical interview with CTO
  3. Recieve offer

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