MatthewLabhttps://matthewlab.com/AI, software and the decisions behind them.enYour token count isn’t your AI bill.https://matthewlab.com/token-counts-and-ai-bills/https://matthewlab.com/token-counts-and-ai-bills/Thu, 05 Nov 2026 01:17:14 +0000Before comparing AI usage, check what the report counts, where the day begins, and which records are missing.Before debugging the value, check the context.https://matthewlab.com/javascript-context-before-coercion/https://matthewlab.com/javascript-context-before-coercion/Thu, 05 Nov 2026 01:17:14 +0000Why the same JavaScript characters can produce different results—and what to preserve in a useful reproduction.A rollback button is not a recovery plan.https://matthewlab.com/rollback-is-not-data-recovery/https://matthewlab.com/rollback-is-not-data-recovery/Thu, 05 Nov 2026 01:17:14 +0000Application code, database state, and uploaded files can travel back to different points in time. Make the boundary explicit.Twenty characters. According to which counter?https://matthewlab.com/javascript-string-length-graphemes/https://matthewlab.com/javascript-string-length-graphemes/Thu, 05 Nov 2026 02:40:12 +0000A name field needs a definition of character before it needs a validation library. Compare code units, code points, visible clusters and storage bytes.The test was green before the fix, too.https://matthewlab.com/regression-test-passes-before-fix/https://matthewlab.com/regression-test-passes-before-fix/Thu, 05 Nov 2026 02:40:12 +0000A unique database row can hide repeated attempts and repeated side effects. Choose the observation that matches the bug.No value is not one instruction.https://matthewlab.com/api-null-empty-omitted-fields/https://matthewlab.com/api-null-empty-omitted-fields/Thu, 05 Nov 2026 02:40:12 +0000An update request can mean keep, clear or reject. Preserve that distinction through form state, JSON serialization and server validation.After Cancel, the old answer can still arrive.https://matthewlab.com/async-ui-cancel-stale-results/https://matthewlab.com/async-ui-cancel-stale-results/Thu, 05 Nov 2026 02:40:12 +0000Transport cancellation and permission to update the screen are separate. Use request identity to stop a late answer from replacing newer input.Does a still 3D scene need another frame?https://matthewlab.com/on-demand-rendering-static-3d/https://matthewlab.com/on-demand-rendering-static-3d/Thu, 05 Nov 2026 02:40:12 +0000A static product viewer and an animation have different inputs. Name the changes that require a redraw before changing the render loop.The container finished. Where did the file go?https://matthewlab.com/docker-container-output-files/https://matthewlab.com/docker-container-output-files/Thu, 05 Nov 2026 02:40:12 +0000A successful exit does not establish that a report survives outside its container. Trace the output path before cleaning up the run.Average first, convert later? The order changes the answer.https://matthewlab.com/average-before-nonlinear-conversion/https://matthewlab.com/average-before-nonlinear-conversion/Thu, 05 Nov 2026 02:40:12 +0000The average of converted measurements can differ from the conversion of their average. A two-number example makes the choice visible.