Build security that ships.
We are a small, senior team building authorization software other engineers trust on their most sensitive paths. If you like hard problems with real stakes — correctness, trust, and the edge case that is the whole job — you will fit right in.
What we value
These shape how we build, review, and ship — and how we treat the engineers who depend on us.
Correctness first
In security, “mostly right” is wrong. We verify, test, and review before we ship — and we would rather be late than be quietly incorrect on an authorization decision.
Adversarial by default
We assume hostile input and design for the failure, not just the happy path. Fail closed, never open. The threat model is part of the design, not an afterthought bolted on at the end.
Ownership end to end
We follow a problem from design through production and stand behind the whole of it — the decision, the code, the docs, and what it does in someone else’s system at 3 a.m.
Clarity is a feature
If a developer cannot understand the secure path in minutes, we have not finished. Clear writing, honest defaults, and documentation are part of the product, not a chore after it.
The B5 engineering standard
Senior, results-driven engineers who take end-to-end ownership of systems that have to be right every time — and stay unyielding about robust, secure, well-documented work.
- Verify everything — never trust the caller
- Make the secure path the easy path
- Fail closed, and make the failure legible
- Think in threat models, not features
- Own the outcome, not just the diff
- Write it down — docs ship with the code
- Sweat the edge case; it is the whole job
- Earn developer trust above all else
Open roles
Don’t see your role? Write to careers@b5secure.com.
Want in?
Tell us what you’d want to build. We read every note.