Notelogs

XSS is still one of the most common web vulnerabilities. This guide explains how XSS works, where React's default protections end, and what you must do explicitly to keep your Next.js app safe.

Decouple deployment from release using feature flags. Learn how to implement gradual rollouts, kill switches, and environment-specific flags in a Next.js application without a third-party service.

Metadata, sitemaps, structured data, crawlability, and Core Web Vitals—every technical SEO lever available to a Next.js developer.

Logs, metrics, distributed traces, and error tracking—a practical guide to knowing what your web application is doing in production.

Multi-stage Dockerfiles, standalone output mode, and production-ready image patterns for Next.js applications running in containers.

Set up lint, type-check, test, and deploy pipelines with GitHub Actions that catch regressions before they reach production.

Tree shaking, dynamic imports, and bundle analysis techniques that cut kilobytes and improve Time to Interactive in Next.js applications.

A practical walkthrough of next/image, modern formats, responsive sizing, and the changes that directly move your LCP score.

A practical reference to TypeScript's built-in utility types—Partial, Pick, Omit, Record, and more—with real examples drawn from API and component work.

Sharing types between your Next.js server and React client eliminates a whole class of integration bugs. Here is the pattern: one schema, one type, zero casting.

TypeScript types disappear at runtime. Zod bridges the gap by validating data at the boundary and inferring static types from schemas — one source of truth for both compile time and runtime.

Discriminated unions let you model state safely and make impossible states unrepresentable. Learn the pattern, exhaustive checking, and where it beats classes and enums.

Generics from first principles: what the type parameter T actually means, how constraints work, and practical patterns you will reach for every week.

Serverless functions can exhaust your database connection limit faster than you expect. This guide explains why it happens, how to cache connections across warm invocations, and how to configure pool size correctly for MongoDB and Postgres.

MongoDB multi-document transactions offer ACID guarantees but come with real overhead. This guide explains when transactions are necessary, how to use them correctly in Node.js, and when to reach for simpler alternatives.

Google ranks on real-user experience, and Core Web Vitals are how it measures that. Here is a practical, framework-aware breakdown of LCP, INP and CLS — what each one means, the usual culprits, and how to fix them in a Next.js app.

The N+1 query problem silently destroys API performance. This guide shows how to spot it in Node.js applications backed by MongoDB or SQL, and how to fix it with batching, projection, and proper joins.

The aggregation pipeline is MongoDB's answer to SQL GROUP BY, JOIN, and window functions. This guide walks through the most useful stages — $match, $group, $lookup, $project, $unwind — with real reporting examples.