Event Contract Lab
Flagship. Draft, freeze, and test a tracking contract against live payloads.
Open the syllabusBlackcraig · measurement studio
We prove the event landed — and that it meant what you named it.
Query Layerbase is a training desk for Analytics QA and Event Validation. You leave with a written contract, a replay checklist, and the habit of failing a release when checkout_started arrives without a currency.
“The duplicate
purchasecatch in module four paid for the seat. We had been celebrating a conversion rate that was counting retries.”Helen P., analytics lead, grocery retail — Glasgow
“Useful, though the warehouse replay week assumes you already have BigQuery access. I spent two evenings waiting on a ticket.”
Client in travel technology — Event Contract Lab, autumn cohort
Programmes
Four desks, one shared stubbornness about names
Tag Plan Reconciliation
Map GTM containers to tickets so orphan tags stop shipping on Friday evenings.
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Consent-Aware Measurement
Check that denied consent actually withholds identifiers, not just the banner copy.
See all programmesWhat we actually inspect
QA that looks at payloads, not slide decks
Most tracking “reviews” stop at a screenshot of GTM Preview. We treat Analytics QA and Event Validation as a product test: expected name, required properties, identity, consent state, and a warehouse row that can be joined without folklore.
- Name and version pinned in a contract, not a Slack thread.
- Required properties typed — string vs number vs missing.
- Duplicate event IDs and retry storms after payment redirects.
- SPA route changes that fire a second
page_viewwith a stale title. - Consent mode mismatches between the CMP and the tag.
A week in the lab
Monday freeze, Thursday replay, Friday gate
Freeze
The cohort locks a slice of the dictionary. If engineering cannot implement it, we cut scope rather than invent a “temporary” name.
Replay
You push a known journey through staging, export the hit stream, and diff it against the contract. Failures are tickets, not vibes.
Gate
We write a release note that says which events are certified. Anything uncertified stays out of the board pack.