Founding Full Stack Engineer (Onsite SF)

Founding Software Engineer

Location : San Francisco (In-Person Preferred)

Type : Full-Time | Founding Team

Stage : YC W25 | $4.1M Seed Raised

Valuation : $35M

Equity : Significant Early-Stage Ownership

About ZeroEntropy

At ZeroEntropy , we're building the world's most accurate search engine for unstructured data - the retrieval layer powering AI agents and LLM applications. In the era of RAG (retrieval-augmented generation), search is no longer a nice-to-have - it's the backbone of next-gen intelligence .

Our platform connects massive, complex knowledge bases to LLMs through purpose-built retrieval infrastructure. Think : vector DB + re-ranker + agent orchestration , engineered from first principles. We're not just chaining APIs - we're rebuilding how AI systems find and reason over information.

What We're Building

• A RAG-native retrieval engine with sub-second latency and high-precision recall.
• Custom-trained AI models tailored for semantic retrieval over unstructured enterprise data.
• Re-ranking algorithms tuned for multi-domain relevance and enterprise-scale accuracy.
• Real-time orchestration layers for AI agents, with low-latency, high-availability guarantees.
• Full-stack pipelines blending infra, AI research, and developer tools.

This is a chance to define a category and ship frontier systems from the ground up.

Why Join ZeroEntropy?

Ideal Background

We're looking for a highly capable and product-oriented engineer who's excited to build foundational systems for AI. You might be a fit if you have :

Must-Haves :

Bonus Points :

Where We Work

We're based in San Francisco and deeply value in-person collaboration . You'll work directly with the founders and sit across the table from other obsessive builders solving hard technical problems with speed and purpose.