Our mission

Help every team know before their users do

Sentinel exists to close the gap between “something broke” and “we knew about it.” We think monitoring should understand what your systems are supposed to do — and tell the right person the moment they stop doing it.

Why monitoring matters

The worst way to learn your product is down is from a customer

Every team that has shipped something real knows the feeling: a quiet Tuesday, a Slack message from a customer, and the slow dread of realizing it had been broken for hours. The health check was green the whole time. The endpoint returned 200. It just returned the wrong thing.

That’s the gap most monitoring leaves open. A status code tells you the server answered — not that checkout completed, that the right rows came back, or that the page rendered without an error banner. We built Sentinel because catching the obvious outages was never the hard part. Catching the subtle ones was.

So Sentinel watches every layer — HTTP, Postgres, Redis, custom flows over SSH — and lets you decide what “healthy” actually means: with declarative rules, with sandboxed code, or with a model that reads a response the way a human would. Then it does the unglamorous, essential work: opens the incident, pages the right channel, tracks the SLA, and shows your customers a status page they can trust.

Know before your users do. Everything we build serves that one sentence.

Watch the whole stack

The edge, the database, and the flow that ties them together — not just the front door.

Prove the uptime

Turn raw checks into SLAs, error budgets and status pages your customers can see.

Stay out of the way

Fast setup, sane defaults, an API for everything. Monitoring shouldn’t become another system to babysit.

Built by operators

“We’ve carried the pager. We’ve written the post-mortem at 4am and explained the outage to customers the next morning. Sentinel is the tool we kept wishing we had — so we built it, with the defaults we’d actually want turned on.”

— The team behind Sentinel, engineers and SREs who’ve run real systems at scale.

What we value

Principles we don’t compromise on

A small set of beliefs that shape every decision — and that we’d happily be held to.

Clarity over noise

An alert you can ignore is worse than no alert. We tune for signal — fewer, truer pages — so the ones you get always mean something.

Depth, not dashboards

Pretty graphs are easy. We care about catching the failure underneath them — the slow query, the expired cert, the silently-wrong response.

Trust by construction

Credentials encrypted at rest, strict tenant isolation, guarded restores. Security isn’t a tier — it’s the floor every plan stands on.

Operators first

We build the tool we wanted on the other end of a pager. If it wouldn’t help us at 3am, it doesn’t ship.

We’re building Sentinel in the open.

Want to help, partner, or just tell us about the outage that still haunts you? We’d love to hear from you.

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Monitoring that earns its place on your team.

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