Calendar integrations are hard. Here is the cheat sheet.
Google, Outlook and iCloud all lie to you in different ways. The map we wish we had when we started building scheduling features.
Every project we ship has the same five-line CI step at the end of the design phase: a perf budget, a JS bundle ceiling, an LCP target on a throttled 3G connection, an a11y axe pass, and a 200 ms TTFB cap on the marketing pages. Miss any one of them and the build fails. Designers see it. Engineers see it. Clients see it.
Stop calling it a target.
A target is something a team aims for at the end of the quarter. A budget is something the system enforces on the way there. The difference between the two is who pays the bill when a stakeholder asks for "just one more script."
We treat performance the way we treat a database migration: write it down, version it, and let a tool gate the deploy. Below is a copy-paste version of the budget we keep on every project.
“Any budget that doesn't fail the build is a wishlist.”
The five rules
- Total JS on landing < 90 KB gzipped.
- LCP < 1.8 s on a Moto G4 throttled to slow 3G.
- CLS < 0.02 on every route under test.
- Zero axe-core serious or critical issues.
- TTFB < 200 ms from edge cache (HTML + Next/Image).
None of this is fancy. The trick is making it boring enough that nobody argues with it on day 90.