Redirect payments and your missing GA4 purchase event
Mollie says it plainly: the customer may not return. Your purchase event lives on the page they never reached.
8 min read
Precisian Blog
Precisian technical blog — AI-powered data integrity
Attributing sales that close inside WhatsApp
The webhook hands you the ad ID, not the campaign. And the person identifier has no equivalent on the web side.
8 min read
Build or buy a data lake: only one side publishes prices
S3 storage is US$ 0.023 per GB-month from a published table. The managed side documents the model and not the rate.
7 min read
Are third-party cookies actually gone? Read the dates
Chrome still enables them by default. Safari and Firefox blocked years ago. The replacement programme was wound down.
7 min read
Answer lineage: auditing what an AI agent actually read
The chat transcript records what was said, not what was true. Lineage links an answer to the definition and data behind it.
6 min read
What breaks in your analytics during peak season
GA4's BigQuery export caps at 1 million events a day, and an exceeded export pauses without reprocessing previous days.
7 min read
Marketplaces return traffic, never its source
Amazon's own schema returns 28 traffic fields per product and zero origin fields. The absence is in the schema, not your integration.
8 min read
Semantic layer vs data warehouse: they don't compete
One stores and computes; the other defines what is being computed. There is no NOT NULL for semantics.
7 min read
Why GA4 and your BigQuery export will never agree
Google lists BigQuery export among features that do not support behavioural modelling. The interface estimates; the export observes.
8 min read
How to tell if your data pipeline broke, or just lied
Airflow documents it in one line: if the run never finishes, the SLA is never checked. That is the easy version.
8 min read
Giving an agency data access without giving everything
GA4 has 5 roles and 2 data restrictions, one hiding revenue. The market default is to grant Administrator anyway.
8 min read
Why your product isn't showing on Google Shopping
Preemptive item disapproval disapproves what Google suspects, not only what it checked. And GTIN is not required; brand is.
8 min read
How long to keep marketing data (GA4 already decided)
GA4 standard allows 2 or 14 months, and large properties get 2. The aggregate report survives; the exploration does not.
8 min read
MCP server vs BI tool: which question is each one for?
A dashboard answers the question already asked; an MCP server answers the one nobody anticipated. Both read the same definition.
7 min read
Why Shopify and GA4 revenue never match
Adobe says it plainly: the two should not match in almost every case. GA4 excludes tax and shipping; Shopify includes both.
8 min read
What is a trusted data layer for AI agents?
Access, definition, freshness and provenance, decided before the question. Connection is solved; trust is what nobody shipped.
7 min read
MCP for e-commerce analytics: expose questions, not tables
The spec makes tools model-controlled and tool annotations untrusted. Your tool surface is the security boundary.
7 min read
Why you can't compute LTV across marketplace and own store
Amazon documents its buyer email as anonymized, and no order carries a traffic source. Cross-channel identity is absent by design.
8 min read
Connecting an AI agent to production data without exposing it
MCP makes authorization optional, and 40.55% of live remote servers expose tools with none. Safety is what you add on top.
8 min read
Is server-side tagging worth it? Read both documents first
Google promises full durability on a subdomain. WebKit caps CNAME-resolved subdomain cookies at seven days. Both are current.
8 min read
Marketing and finance never close the same revenue number
Both numbers are right. The accounting standard recognises revenue on transfer of control; marketing measures at checkout.
8 min read
What is a data contract, and what does it enforce?
A data contract declares shape, guarantees and meaning. On Snowflake, BigQuery and Redshift, a declared primary key is enforced by nobody.
6 min read
Why your reported ROAS exceeds actual revenue, mechanically
Google documents that other platforms take full credit for a conversion with other touchpoints. Nobody deduplicates across vendors.
8 min read
Teaching a data agent to say I don't know, and why that is hard
On a benchmark that prices wrong SQL, abstaining from everything scores 50% and the best real systems score 29.8% to 54.5%.
8 min read
Prompt injection through marketing data: the fields nobody validates
A Google Ads campaign name takes 256 characters with no documented content validation. Meta documents no maximum at all.
8 min read
Agents Schema and MCP: not competing standards, and the difference that matters
Fivetran's own FAQ answers 'Do I need MCP?' with 'No. MCP is one option.' They are layers, not rivals. The real difference is governance.
6 min read
Per-tenant isolation for MCP: giving access without giving away the warehouse
Row-level security fails at the role the agent connects with. Per-tenant isolation moves the boundary out of application code and into architecture.
8 min read
Query cost guardrails: what an AI agent can do to your warehouse bill
An AI agent can scan your whole warehouse without breaking a rule. Adding a LIMIT does not reduce what you are billed on non-clustered tables.
8 min read
What actually goes into a semantic layer, field by field
A semantic layer is where your metric definitions live in a form a machine reads before it computes. Not a tool: a set of written decisions.
7 min read
Metric hallucination: why your AI reports a different number than your dashboard
Metric hallucination is AI computing correctly on a definition nobody wrote down. Supplying the definition raised accuracy from 45.5% to 67.7%.
7 min read
Regional Holdout: The Only Real MMM Validation Test
Regional holdout is the only test that separates an MMM that found real signal from one that memorized noise. Learn to design and run it.
8 min read
Welcome to the Precisian Blog
Our first article explains what to expect from the Precisian blog: technical insights on GA4, data quality, attribution, and analytics engineering.
3 min read