Use WebP/AVIF for 30-50% smaller files. Lazy load images below the fold. Serve responsive images with srcset. Use a CDN for fast delivery. Compress before upload. Modern formats + lazy loading = 70% faster loads.
N+1 queries happen when you fetch records in a loop - 1 query becomes 1000. Detect with query logging and APM tools. Fix with eager loading, joins, or batching. 100x performance improvement is common.
Use structured logging with levels. Log requests, errors, and key events - not sensitive data or debug spam. JSON format for aggregation. Keep performance impact under 5%. Fix log leaks before they become breaches.
Never commit secrets to Git. Use .env files locally, environment variables in production. Validate config on startup. Use dotenv for Node.js, never hardcode credentials.
Use proper HTTP status codes. Return consistent error format with code, message, and details. Log errors server-side. Never expose stack traces to clients.
URL versioning (/v1/users) is simplest and most discoverable. Header versioning is cleaner but harder to use. Start with URL versioning, only use headers if you have a strong reason.
Offset pagination is simple but slow on large datasets. Cursor pagination is fast and consistent. Use offset for small datasets, cursor for anything over 100k rows.
Sessions are simpler and more secure for traditional web apps. JWTs work better for APIs and microservices. Sessions require server state, JWTs don't. Pick based on your architecture, not hype.
Never block API responses with slow operations. Use job queues for emails, image processing, reports. Bull with Redis is simple and reliable. Process jobs in workers, not request handlers.
Caching makes apps fast. Use in-memory for single servers, Redis for distributed systems, CDN for static assets. Implement cache-aside for most use cases, write-through for consistency.
Rate limiting prevents API abuse. Token bucket is most flexible, fixed window is simplest, sliding window is most accurate. Implement in-memory for single servers, Redis for distributed systems.
Git worktree creates multiple working directories from one repository. Check out different branches side-by-side without stashing. Faster than multiple clones, cleaner than branch switching.
Indexes make queries fast by avoiding full table scans. But too many indexes slow down writes. Use EXPLAIN to identify slow queries, add indexes on WHERE/JOIN columns, and avoid indexing everything.
SQLite can handle 100k+ requests/second and terabytes of data. For read-heavy apps, single-server deployments, and edge computing, it's simpler and faster than Postgres. Know when to use it.
Every few years, a new database paradigm claims it will kill SQL and relational databases. But they always end up adding SQL interfaces and relational features. History keeps repeating itself.
SSE is simpler than WebSockets for one-way server-to-client updates. Built into browsers, works over HTTP, automatic reconnection. Use WebSockets only when you need bidirectional communication.
Microservices add operational complexity that small teams can't afford. Monoliths are faster to build, easier to debug, and simpler to deploy. Split services when you have a reason, not because it's trendy.
ORMs hide complexity that eventually bites you. Raw SQL is explicit, performant, and easier to debug. Use ORMs for CRUD, write SQL for anything complex.
Build a complete URL shortener in 30 lines of Go using only stdlib. Generates short codes, handles redirects, stores in memory - perfect learning project.
Unix philosophy teaches us that simple, focused tools that do one thing well often outlast complex alternatives. Modern examples like grep, git, and curl prove this approach still works.
UUID v7 puts timestamps at the beginning, making database indexes happy. I saw 3x better insert performance and 50% smaller indexes after migrating. Here's how and when to switch.
CORS errors are never quite the same. Here's every fix I've used in production, why each error happens, and actual code you can copy-paste for your specific situation.
Frameworks solve real problems but add complexity. Use them when they solve problems you actually have, not because they're trendy. Sometimes vanilla code is faster to write and maintain.
WebAssembly lets you run compiled languages like C, Rust, and Go in browsers at near-native speed. Perfect for performance-critical apps, games, and computational tasks.
Master these 15 Linux command combinations to handle logs, find files, process data, and monitor systems like a pro. Copy-paste ready with explanations.
0x is the universal prefix for hexadecimal numbers — a compact, human-friendly way to represent binary values used in code, memory addresses, crypto wallets, and even CSS color codes.