Security testing by people who actually break things.
Zentinel was built around a simple observation: software changes faster than traditional security testing.
Most teams buy a penetration test once a year, usually because a customer or an auditor asked for one. The report describes an application as it was during a two-week window. By the time the fixes ship, the product has moved on: new endpoints, new roles, a new integration, a new region. The test is accurate and already out of date.
Zentinel exists to keep security testing in step with how startups ship. Automated monitoring keeps track of what an attacker can see from outside. Human security engineers test the application on a regular cadence and whenever something significant ships, prove what breaks, and replay the attack after you fix it.
Across 28 startups we have identified 200+ security findings, with 0 false positives shipped through our audit process. The same classes come up again and again in fast-moving products: broken access control, trust placed in the client, forgotten infrastructure. They are rarely exotic. They are simply untested.
Alvin leads Zentinel's offensive testing and the methodology behind it. Every engagement has a named engineer you can talk to directly, from scoping through the last retest.
How we work
Written authorization before anything starts. Testing inside the agreed scope only. Non-destructive by default. Evidence kept to the minimum that proves impact. The details are on the trust page and the method.
Contact
Questions about scope, a security review, or something you found on this site: hello@zentinel.dev
Your application keeps changing.
Your security should keep testing.
Put your application into the Zentinel loop.
Authorized testing only. All testing occurs within agreed scope and rules of engagement.