Anyone can write SQL now. Knowing which queries survive production is the hard part.
Clusterity is a small PostgreSQL practice. We train engineering teams to tell the safe query from the 3 a.m. page, and we build the products and open-source tools that apply the same judgment every day.
Services
Judgment, taught.
Workshops and an annual program. Built from a decade of production failures, not from documentation.
Tools
Judgment, encoded.
Two products and three open-source tools. Hosted insight over your schema and planner, hands-on labs, and CLIs that run on every commit. Commercial where it earns it, free where it should be.
Half of what we do is teaching. The other half is encoding what we teach. Same judgment, in the room and in the code.
01 · Services
Training first. Everything else hangs off it.
prices ex. VAT, EUR
Annual Training Program
It starts with a diagnostic call to find the problems and a first workshop that sets the foundation. The other three are shaped by what we found and agreed on. At month twelve we re-test, so you get a before-and-after, not a certificate. Four quarterly workshops, labs and office hours, for less than the workshops alone.
- Diagnostic call and a baseline from at least three dryrun snapshots of your schema, planner and workload
- Quarterly workshops. The first is a fixed foundations curriculum for the whole team
- Workshops two to four are defined together after the first, on your gaps
- Full SQL Labs access for the whole team
- Monthly office hours for real review questions
- Re-test and written report at month twelve
+€900 per additional engineerdesign a program →
Workshops
Focused, practical sessions. The supervision format: your AI agent proposed this migration; find the trap, ship the fix.
- Migration safety and lock-aware DDL
- Reading plans before they read you
- Reviewing AI-generated SQL with intent
full-day €4,000your team, up to 8 engineerscheck availability →
02 · Tools
What we teach in a room, these apply every day.
products first, open source below
Hindsight
Hosted snapshot and insight engine. Push schema and planner snapshots from CI or a laptop, get findings the whole team can see, and keep the record of what changed and why.
- Schema and planner drift between snapshots
- Findings the whole team can see and comment on
- A snapshot is DDL, planner statistics and activity counters. No rows, no credentials.
SQL Labs
Realistic sandboxes where you safely break things on production-scale data. The edge cases tutorials can't teach because they've never seen them. Included in the annual program.
- Supervision labs: trust, but verify the agent
- Performance and migration boss fights
- Scored, repeatable, drawn from real incidents
team from €1,990 / yearrequest early access →
dryrun
Full PostgreSQL schema intelligence for AI agents and CI. Production planner behavior, portable, with no database credentials and zero production risk.
RegreSQL
The regression net. Captures expected query output and EXPLAIN costs, then catches the drift before it becomes an incident.
Fixturize
Production-faithful, FK-consistent, PII-masked test data in minutes. The realistic substrate the labs and tools run on.
Open source lives at github.com/boringSQL. Free to use, free to fork, no upsell inside.
03 · Writing
Two places we write. Kept deliberately apart.
boringSQL
impartial · vendor-neutralPostgreSQL internals and production patterns, explained in depth. No vendors, no products, no pitch.
Field notes
vendor-specific · commercialVendor specific, managed offerings, our own tools, and what we saw on engagements. It would compromise boringSQL, so it lives here.
Nothing published yet. The first note is being written.
04 · Who
Small on purpose.
No bench, no juniors, no account managers. The person who writes the article, builds the tool, and runs the workshop is the person you talk to. We take on a handful of teams a year and say no to the rest.
Today that person is Radim. The next hire is an engineer, not a salesperson.
Clusterity s.r.o., Czech Republic. Working globally, remote and on-site possible.
writes boringSQL, builds dryrun
05 · Talk
Start with a free diagnostic call.
Bring the migration you're planning, the incident you had, or the upgrade you keep postponing. We'll point you at the right entry: a workshop, the program, the labs, or just an answer.
Regus, D1 Říčany Obchodní 1623/14
251 01 Říčany u Prahy
Czech Republic billing Clusterity s.r.o.
Slepá 391
251 01 Světice
Czech Republic