Subimage (YC W25) | Founding Engineer

About

Hihi, I'm Alex, co-founder and CEO. Subimage maps infrastructure the way an attacker does so security teams at scale-ups and enterprises can find and fix problems. We're built on Cartography (https://cartography.dev), the open source infra mapping tool we helped create at Lyft and donated to the CNCF. It runs at over 70 companies, including 7 in the Fortune 100.

We're a tiny seed-stage team and our customers are companies your parents have heard of. We have more demand than we can build for, which is why this post exists. This is a chance to get in on the ground floor of something big (or to find out quickly that it won't work; just being upfront about it).

Problems You'd Be Working On

Vulnerability triage with real context: is the asset internet-facing, through which services, is the vulnerable function actually reachable in code, are there compensating controls, and what sensitive data does it reach once exploited, across how many hops.
Proving that the security fixes our agent proposes won't break anything.
A near-real-time, self-updating map of an environment so you can see an attack as it happens, plus "time travel" in the graph so you can replay it afterward.
Teaching an agent to answer questions about a large graph quickly, with only the context it needs and without making mistakes.
Determining who owns a given resource from messy signals like tags, actions, logs, and files.

Stack

Cartography for ingestion
Neo4j for the graph
Python/FastAPI backend
Svelte frontend with a homegrown WebGL graph renderer
An MCP server that exposes all of it to agents
Terraform for IaC

Who We're Looking For

3+ years at high-growth companies
Strong distributed systems and cloud experience
A real sense of ownership
First-principles thinking
A willingness to implement gnarly business logic (elegantly, ideally) if it makes a jaded security engineer's life easier
Kubernetes and security knowledge are nice to have, not required
You're in the Bay Area and want to be in the office five days a week

Process

Technical screen, call with the founders, a paid day working with the team, then offer.

Health/vision/dental, 401k match, gym, team lunches, unlimited PTO.

Apply here and mention HN: Apply here