Production Bugs

Why is my Python multiprocessing code slower than single-thread execution?

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# Why is my Python multiprocessing code slower than single-thread execution? ## Summary Multiprocessing implementations in Python can run slower than single-threaded versions when: – High inter-process communication (IPC) overhead exists – The computational payload per process is insufficiently large – System resource constraints limit parallel scaling The provided example exhibits these characteristics due to … Read more

Why does setState() not update UI immediately in Flutter?

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# Why setState() Does Not Update UI Immediately in Flutter? ## Summary In Flutter, `setState()` triggers a widget rebuild but doesn’t update the UI synchronously. Instead, it schedules a rebuild request scheduled for the next frame cycle, causing a perceived delay before UI changes appear. This behavior stems from Flutter’s batched rendering approach for performance … Read more

Best architecture for conditional file visibility (Public vs. Friends-Only) using Supabase RLS and JSONB?

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# Postmortem: Performance Degradation and Access Flaws in User Gallery Visibility System ## Summary An RLS policy implementation for conditional file visibility caused severe performance degradation during peak traffic and allowed unauthorized access to private galleries. The policy relied on real-time JSONB settings parsing and complex friend-check subqueries. ## Root Cause – The RLS policy … Read more

Missing required parameter for [Route: password.reset] [URI: password/reset/{token}] [Missing parameter: token]

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# Production Incident Report: Route Parameter Missing After Framework Upgrade ## Summary A Laravel 11 to 12 upgrade caused login failures due to a missing route parameter in the password reset link generation. The application generated `Missing required parameter for [Route: password.reset]` errors when users attempted to load the login page, preventing authentication workflows. ## … Read more

Flowbite Inline Datepicker — Unable to customize styles (borders, colors, selected date, other month days)

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# Flowbite Inline Datepicker — Unable to Customize Styles Postmortem ## Summary Customization attempts for the Flowbite inline datepicker (borders, colors, selected date) failed because: – Tailwind CDN doesn’t support complex arbitrary variants dynamically – Flowbite’s dynamically injected DOM elements bypass initial Tailwind processing – Component styles require specific data attributes/CSS variables for overrides ## … Read more

Slick arrow color and border color

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# Postmortem: Styling Customization Failure in Slick Slider Implementation ## Summary A developer attempted to customize Slick slider arrow colors and border styles but could only find documentation for modifying arrow background colors. This resulted in delayed feature implementation and required CSS detective work to resolve. The root issue was insufficient understanding of Slick’s DOM … Read more

How to intercept browser back button / trackpad swipe in React and redirect to a specific route instead of history back

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# Intercepting Browser Back Navigation in React: Pitfalls and Solutions ## Summary Attempts to forcibly redirect users to a fixed route (e.g., `/settings`) when pressing the back button or using trackpad swipes break expected browser navigation behavior. Using `popstate` to override history entries instead of leveraging React Router’s capabilities causes navigation conflicts. ## Root Cause … Read more

Error thrown when I try to console log a ZodError

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# Postmortem: Error Thrown When Logging ZodError in TypeScript ## Summary An attempt to log Zod validation errors using `console.log(error)` unexpectedly throws an error instead of printing diagnostic information. This occurs because `ZodError` contains circular references via its `.issues` array, causing JSON serialization to fail during console output. ## Root Cause – **Circular references in … Read more

Xcode Memory Graph shows leaks in brand new Kotlin Multiplatform + SwiftUI app (__NSArrayI, __NSCFString, MTLAttributeInternal)

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# Xcode Memory Graph Shows Leaks in Kotlin Multiplatform + SwiftUI App ## Summary – Xcode Memory Graph reported immediate leaks (`__NSArrayI`, `__NSCFString`, `MTLAttributeInternal`) in a brand-new Kotlin Multiplatform (KMP) + SwiftUI app – Leaks occur in the default Compose Multiplatform template without custom code – Memory usage stabilizes over time with no actual growth … Read more

PHP form data not saving in MySQL database using mysqli

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# Postmortem: Failed Data Insertion in PHP/MySQL Form Handler ## Summary Form submissions weren’t persisting in MySQL despite valid database connections and table structure verification. The key failure was inadequate error handling masking underlying SQL processing failures, compounded by SQL injection vulnerabilities. ## Root Cause – **Absence of runtime error reporting** silenced critical MySQL constraint … Read more