Privacy is architecture
Not a policy page, not a settings toggle. Identity that cannot persist, storage that does not exist, suppression enforced at query time. If privacy depends on trust, it isn't privacy.
About
Built on one refusal:
privacy or depth? No.
Observer is made by Castomo, the team behind a privacy-first web stack — built in Wrocław, Poland. We watched every analytics platform force the same bad trade: consent banners for depth, shallow reports for privacy. So we built the platform that refuses the trade.
Principles
Four rules we build by.
Claims are tests
Every number on this site is asserted by an automated test — 95 of them, plus a browser privacy suite. If we can't test it, we don't claim it. If we can, you can rerun it.
Honest metrics only
Devices are estimated device-days, never "unique users". Engaged time pauses when the tab hides. Conversion rates show denominators. Badges say exact, estimated, sampled, suppressed.
Your hardware, your data
Self-hosted means self-hosted: no third-party endpoint, no subprocessor, no international transfers. The zero-dependency serving path means no supply chain to audit, either.
Status
v0.1.0 — fully working.
53 of 53 planned capabilities shipped. 95 automated tests passing. Running in production deployments today. The open-source decision is pending; access is onboarded directly.
53/53
capabilities shipped — coverage index 100%
20
capabilities unique across the 15-competitor field
0
npm packages in the serving path
Made by Castomo.
Verified by you.
Wrocław, Polska — the same team that ships privacy-first web infrastructure.