How I Verify Azure Pricing Accuracy Against Real Invoices (And Why I Had To)

From "AI garbage" accusations to a trusted calculator — the technical journey of validating every price on AzureCalc.uk I built an Azure cost calculator https://www.azure-calc.co.uk/ as a weekend project. The first piece of feedback I got was: “this looks AI-generated.” They weren't entirely wrong. Ouch.. fair as I had hardcoded pricing constants, generic guide content, and no methodology transparency. The antidote to "AI garbage" is showing your working. This article explains exactly how I did that. Layer 1: The Data Pipeline — Azure Retail Prices API to Cloudflare D1 The foundation is the Azure Retail Prices API ( prices.azure.com ). Unlike scraping or manual spreadsheets, this is Microsoft's official price feed. But it's 50,000+ rows for UK South alone, updated monthly. You can't query this in real-time for every calculator request. The Worker filters to UK South, GBP-only, then inserts into a database table. This gives us: Layer 2: The Verification Trap — Hardcoded Constants vs. Li