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Semble

13 open roles

Founding AI Engineer

$150k to $250k

San Francisco, CA, USFull-time1+ yearsPosted Nov 14, 2025

Against the San Francisco typical range

Job description

We're building AI agents that design building-systems (fire, HVAC, plumbing, security) instantly and code-compliantly.

The $600B building-system integration industry still runs on spreadsheets and manual drawings, even as building codes rapidly evolve and become more localized. It’s a massive blind spot for the tech world.

We are transforming building-system design from a months-long, error-prone process into an instant, automated workflow. Semble AI is becoming the industry standard for top quality commercial building design.

What you’ll work on

As a founding engineer, you’ll work directly with the founders to own and build systems such as:

  • Vision pipelines that segment rooms, walls, and architectural elements from noisy PDFs/CAD files
  • LLM + RAG workflows that interpret building codes and produce compliant designs
  • Full-stack features across our React/Node/Postgres platform

You’ll have massive ownership and help set the technical direction of a company in a market that’s about to undergo a once-in-a-generation transition.

Our tech

  • Typescript / React / Node / Express / PostgreSQL
  • Python (PyTorch, NumPy, etc.)
  • Vision models: object detection, instance + semantic segmentation
  • AI Agents: multi-agent reasoning, workflow orchestration, MCP
  • RAG pipelines: vector DBs, embeddings, chunking strategies

You might be a great fit if you

  • Have strong experience in ML (vision AND LLMs), backend, building AI agents, and full-stack engineering
  • Thrive in fast-moving environments and love shipping end-to-end
  • Care about building reliable, production-grade AI systems
  • Want to be early at a YC startup where your work directly defines the company’s trajectory

Why join us

  • You’ll work directly with the founding team (YC F25)
  • Ship real AI systems into production for companies across the U.S.
  • Own major pieces of the product and architecture
  • Help shape the engineering culture from day zero
  • Build something that will become the industry standard for top quality commercial building design

Description copied from Semble's careers page. Read the full posting before you apply.

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