https://issackjohn.github.io/ Notes on browser performance, benchmark design, and engineering automations by Issack John. en-us https://issackjohn.github.io/automations/monitoring-the-visa-bulletin-with-chatgpt.html https://issackjohn.github.io/automations/monitoring-the-visa-bulletin-with-chatgpt.html Mon, 24 Aug 2026 00:00:00 GMT A scheduled prompt routine to track U.S. State Department Visa Bulletin movements and priority dates automatically without manual monthly checking. https://issackjohn.github.io/blog/who-actually-uses-js-call-stacks-in-crash-reports.html https://issackjohn.github.io/blog/who-actually-uses-js-call-stacks-in-crash-reports.html Fri, 24 Jul 2026 00:00:00 GMT Fourteen months after Chrome shipped include-js-call-stacks-in-crash-reports, a scan of the Tranco top 5,000 to find out who deployed it — and why a header-based opt-in is its own telemetry. https://issackjohn.github.io/blog/fixing-a-reporting-api-race-in-chromium.html https://issackjohn.github.io/blog/fixing-a-reporting-api-race-in-chromium.html Fri, 24 Jul 2026 00:00:00 GMT A crash report could be dropped because its reporting source was expired before the report finished being added to the cache. Fixing the ordering re-enabled a long-disabled test suite. https://issackjohn.github.io/blog/fixing-intl-datetimeformat-corruption-in-v8.html https://issackjohn.github.io/blog/fixing-intl-datetimeformat-corruption-in-v8.html Thu, 12 Feb 2026 00:00:00 GMT How a standard C++ string move/copy chain caused Intl.DateTimeFormat to fail on Windows x86 official builds, and how replacing it with const char* made it faster and safer. https://issackjohn.github.io/blog/when-two-profilers-share-a-thread.html https://issackjohn.github.io/blog/when-two-profilers-share-a-thread.html Wed, 12 Nov 2025 00:00:00 GMT How concurrent CPU profiling streams from the JS Self-Profiling API and internal tracing could corrupt attribution in DevTools, and how tagging each stream by source fixed it.