Developer Debugging Guides
Step-by-step fixes for Next.js, Supabase, Cursor AI, shadcn/ui, Tailwind, and Vercel errors. Real error messages, real solutions.
How to Check Your Node.js Version (All Methods)
Learn how to check your Node.js version with node --version, nvm, and inside any project. Covers all methods to check node version across every OS.
Coding Errors: 8 Types and How to Fix Each One
Learn to identify and fix the most common coding errors — syntax, runtime, and logic errors — with a practical debugging workflow and real code examples.
Docker Compose Volumes: Mount, Persist & Share Data
Master docker compose volumes with working syntax, named volumes, bind mounts, and fixes for the most common data-loss and permission errors.
How to Stop a Docker Container (3 Ways)
Learn how to stop a Docker container cleanly with docker stop, force-quit with docker kill, and freeze with docker pause — with real commands and output.
Git Fetch vs Pull: What's the Difference?
Git fetch vs pull explained clearly: what each command does, when to use each, and why fetch-then-merge beats a blind git pull in team workflows.
How to Hire a Startup Developer (Without Regrets)
Need to hire a developer for your startup? Learn the real costs, interview questions, red flags, and when on-demand senior dev help beats a full hire.
What Is Pair Programming? (And Why It Works)
Pair programming unblocks stuck developers fast. Learn the driver-navigator model, real benefits, remote setups, and when on-demand pairing beats AI tools.
Run Postgres in Docker: The Complete Setup Guide
Learn how to run Postgres in Docker with docker run and Docker Compose. Covers env vars, volumes, ports, and common postgres docker errors.
What Is a Pull Request? A Developer's Guide
A pull request (PR) is how developers propose code changes for review before merging. Learn how to create one, write great descriptions, and pass code review.
React Hook Form Not Working? 5 Fixes (2026)
Struggling with react hook form errors? This guide fixes validation not triggering, TypeScript issues, Controller bugs, and broken resets in v7.
Rubber Duck Debugging: Does It Actually Work?
Rubber duck debugging is a real, research-backed technique. Learn how to do it, when it works, and when you need a human senior dev instead of a duck.
TypeScript Enums: When to Use Them (and When Not To)
A practical guide to typescript enum patterns — numeric, string, and const enums — plus when to replace them with union types. With working code examples.
TypeScript vs JavaScript: Which Should You Use?
TypeScript vs JavaScript: understand the real differences, performance tradeoffs, and when to use each — so you can make the right call for your project.
Fix: supabase_internal_image_registry Error — Use Docker Hub When ECR Is Blocked
Getting 'supabase_internal_image_registry' errors when ECR is blocked? Set SUPABASE_INTERNAL_IMAGE_REGISTRY=docker.io to pull from Docker Hub. Works in terminal, docker-compose, and CI/CD.
Fix 'ReferenceError: window is not defined' in Next.js App Router (2026)
Getting 'window is not defined' in Next.js? It means browser code is running on the server. Fix it in 2 minutes with useEffect, typeof window guard, or dynamic import with ssr:false.
Cursor context window full — how to clear it without losing your chat
Cursor saying context is full? Here's how to prune files, use Clear Context, and avoid losing your conversation history. Takes 30 seconds.
.cursorrules is deprecated — switch to .cursor/rules (.mdc) instead
Cursor now uses .cursor/rules/*.mdc instead of .cursorrules. Here's how to migrate your existing rules file in under 5 minutes, with examples.
Fix Cursor Shadow Workspace 100% CPU Usage (2026)
Cursor Shadow Workspace pegging your CPU at 100%? Disable it in Settings in 30 seconds. Here's exactly where the toggle is and why it happens.
How to Use 'use client' Correctly Without Breaking Next.js SEO
Is 'use client' hurting your SEO? Learn the 'Leaf Component' strategy to keep your Next.js pages static and high-ranking while still adding interactivity.
Fixing Radix UI Dependency Conflicts in Shadcn (2026)
Conflicting Radix UI versions breaking your Shadcn components? Learn how to use npm overrides, clean your lockfile, and fix peer dependency errors in your UI library.
Shadcn components/ui/select.tsx dropdown hidden — fixed in 2 lines (2026)
Shadcn Select dropdown hidden behind other elements? Add SelectPortal to components/ui/select.tsx — 2-line fix that bypasses z-index and overflow:hidden parent containers.
supabase_internal_image_registry: use Docker Hub when public.ecr.aws is blocked
supabase start failing because public.ecr.aws is blocked? Set SUPABASE_INTERNAL_IMAGE_REGISTRY=docker.io to pull from Docker Hub instead. Exact command included.
Fix Supabase Unique Constraint Errors (2026)
Getting 'duplicate key value violates unique constraint' in Supabase? Fix it fast with .upsert() and onConflict — covers composite keys and multiple columns.
Stop Cursor AI from Writing Python in Your JavaScript (2025 Guide)
Is Cursor AI hallucinating the wrong programming language? Learn how to stop 'Language Drift' and keep your AI focused on the correct syntax for your project.
How to Fix Cursor Composer 'Connection Failed' (2025 Guide)
Cursor Composer connection failed? This guide covers API rate limits, network interference, session timeouts, and the 10-minute fix for AI editor connectivity issues.
Stop "Lazy AI" Comments and Placeholders in Cursor
Tired of the AI returning '// ... rest of code' instead of the full file? Learn how to fix 'Lazy AI' in Cursor using specific prompts, .cursorrules, and scoped edits.
What to Do When Cursor AI is Stuck on "Thinking..."
Fix the 'Thinking...' loop in Cursor AI. Learn how to debug model timeouts, clear oversized context, and reset your AI flow when the spinner never stops.
Fix: params are undefined in Next.js App Router Server Component
params undefined in your Next.js server component? Learn how to handle the async breaking change in Next.js 15 and properly await your dynamic route data.
Fix: 'NextRouter was not mounted' in Next.js App Directory
Getting the 'NextRouter was not mounted' error? Learn why next/router fails in the App Router and how to correctly use next/navigation for Next.js 14 and 15.
How to Pass Data from Server to Client in Next.js
Master the data bridge in Next.js App Router. Learn how to pass data from Server Components to Client Components using props and composition without hydration errors.
Fix "You Are Importing a Component That Needs 'use client'" in Next.js
Resolve the Next.js boundary error. Learn how to fix 'You are importing a component that needs use client' by understanding the Server vs. Client component model.
Fix Supabase 'Auth Session Missing' on Page Refresh (Next.js)
Supabase signing you out on refresh? Learn how to fix 'Auth session missing' by properly configuring Middleware and cookie-based persistence in Next.js App Router.
Fix: Supabase Realtime Subscription Not Receiving Updates
Supabase Realtime not working? Learn how to fix 'no updates received' by enabling replication, auditing RLS, and debugging your WebSocket connection.
Fix: 'RLS policy violates row security' in Supabase (2025)
Supabase RLS error? Learn how to fix 'RLS policy violates row security' by solving infinite recursion and properly using auth.uid() in your Postgres policies.
Tailwind classes not applying in Shadcn? Add the component path to tailwind.config.js
bg-red-500 in your className but the button ignores it? 90% of the time it's a missing content path in tailwind.config.js. Before/after config shown.
Fix: Tailwind @layers Not Working in Next.js globals.css (2025)
Tailwind @layer base or utilities not applying? Learn how to fix CSS layer mismatches by auditing your import order and Next.js CSS injection points.
Vercel 403 Forbidden on images — add remotePatterns to next.config.js
Images loading locally but returning 403 on Vercel? Missing remotePatterns is the fix. Works for Google, S3, Cloudinary, and any custom domain.
Fixing 504 Gateway Timeout on Vercel Serverless Functions
Vercel 504 error? Learn how to fix 'Gateway Timeout' by optimizing slow database queries, handling external API latency, and managing Vercel's execution limits.
Fix: Environment Variable 'Undefined' on Vercel (Next.js Guide)
Vercel environment variables not working? Learn the difference between build-time and runtime vars, the NEXT_PUBLIC prefix, and how to fix undefined variables in production.
Shadcn UI 'Component Not Found' After Installation - Fixed (2025 Guide)
Shadcn component not found after install? This guide covers path alias fixes, components.json configuration, TypeScript mapping errors, and when to escalate beyond DIY debugging.
Fix Next.js Hydration Errors — React 19 & Next.js 15 Complete Guide (2026)
Next.js hydration failed? Updated for React 19 and Next.js 15. Covers the new 'cannot read property of undefined' hydration crash, async params mismatch, 8 root causes, 5 quick fixes, and a systematic debugging workflow.
How Cursor's Apply button works (and why it rewrites the whole file)
Cursor's Apply button not doing what you expect? Here's exactly how it diffs and patches your file — and when it falls back to a full rewrite.
Vercel build failed "command failed with exit code 1" — how to read the logs and fix it
Exit code 1 just means "look at the logs." Here's how to find the actual error — TypeScript, ESLint, missing env vars, and dependency issues all covered.
Prevent Cursor From Deleting Your Entire File When Updating Code
Stop Cursor AI from replacing your whole file with 'Rest of code here...' placeholders. Learn the correct way to scope your AI edits using selections.
Fix "Prop className did not match" Error in Next.js & Tailwind
Resolve the 'Prop className did not match' warning in Next.js. Understand how CSS-in-JS and conditional classes cause server/client mismatches and how to fix them.
Fix "Text Content Does Not Match Server-Rendered HTML" in Next.js
Solve the dreaded hydration mismatch error in Next.js. Learn why server HTML differs from client renders and how to fix it with useEffect, suppressHydrationWarning, and proper nesting.
Fix "npm install" Peer Dependency Conflicts (ERESOLVE Error)
Solve the 'ERESOLVE unable to resolve dependency tree' error in npm. Learn when to use --legacy-peer-deps and how to fix version conflicts safely.
Handling Supabase "JWT Expired" Errors in Next.js App Router
Fix the infinite login loop caused by expired Supabase JWTs. Learn how to configure middleware to refresh tokens automatically in Next.js App Router.
How to Center a Div in Tailwind CSS (The Definitive Guide)
Stop guessing with Flexbox. Learn the 3 foolproof ways to center a div in Tailwind CSS: Flex, Grid, and Absolute positioning. Copy-paste solutions included.
How to Ignore TypeScript Errors During Vercel Build
Deploy your Next.js app to Vercel even with TypeScript errors. Learn how to configure next.config.js to ignore build failures when you need to ship fast.