bblog

Today I Learned

Daily reflections on work and learning—what I did and what I learned.

Alla11yanimationarchitecturebabelbrowserbrowser-compatbrowser-extensionbundlebundlingcachingcanvasci-cdclscollaborationcompound-componentcssdebuggingdrag-and-dropeditoreslintetaghydrationimagesimeimmutabilityindexeddbinfinite-scrollisrlanding-pagelcpmeasurementmessage-passingmigrationmobilemodalmonorepomotionmutation-testingnavigationnetworknextjsobject-urlofflinepage-transitionpaginationperformanceplaywrightpointer-eventspolyfillproxyreactreact-hooksreact-queryredirectreliabilityrpcscrollsearchsecurityselectionseoserverlessservice-workershellssrstorytellingstructured-datatanstack-querytddtelemetrytest-oracletestingtext-anchoringthemingtype-safetytypescriptundousesyncexternalstorevariancevirtualizationwebpackwebsocketworkflow
Search starts automatically 350ms after you stop typing.

2 entries · #cls

2026년 8월

2026-08-07

What a middle layer passes through and what it guesses — proxies, input commit, image ratios

An infinite redirect caused by a rewrite passing an upstream 3xx straight through, Korean input committed before composition ended, and image ratios that were being guessed as 16:9 — what I learned auditing what middle layers pass through and what they assume

  • A rewrite is a proxy, not a redirect, so it hands the upstream's 3xx straight to the browser
  • Treat a Korean input bug as a commit-boundary problem first, not a value-normalization problem

2026년 7월

2026-07-03

Perf Is a 3× Median; Prefetch Comes as a Set with Skeletons

Sorting out lab-trace outliers, SSR prefetch query-key alignment, CLS skeleton reservation, and server-injected JSON-LD in one day

  • A single dev-server Performance trace often has outliers, so before/after must be compared with the median of N reloads.
  • SSR prefetch is a cache miss if the query key differs from the client by even one character, and it must be treated as a set with skeleton-height reservation, or CLS results.