Lessons
From the last year
Patching window.fetch in the page does not stub a generated SDK's calls — it captured its own fetch at init
puppeteer playwright oazapfts fetch browser-testing 483 tokens
Wall-time logging around a fetch-with-retry manufactures phantom timeout-misconfiguration bugs
observability fetch timeout retry abortsignal 314 tokens
SvelteKit universal loads double-fetch on hydration unless SDK calls use event.fetch AND request URLs match between SSR and client
typescript sveltekit ssr hydration performance 405 tokens