Articles, guides, and developer references

40 React Interview Questions and Answers (2026 Edition)

40 React interview questions covering Hooks, Server Components, Actions, the React Compiler, and React 19.2 features like useEffectEvent and Activity. Updated for 2026.

Sep 6, 202642 min readZeeshan Tofiq

Node.js Dropped --experimental-transform-types: What Breaks and How to Fix It

Node.js 26 (and 24.12+/25.2+) removed --experimental-transform-types. Here's exactly why your TypeScript enums broke and how to fix them.

Aug 22, 202613 min readZeeshan Tofiq

Testing PostgreSQL RLS Policies With Jest (No pgTAP)

Test PostgreSQL row-level security with Jest and node-postgres, no pgTAP required. Catch tenant isolation bugs in CI before a bad grant reaches production.

Aug 21, 202614 min readZeeshan Tofiq

Mongoose and TypeScript: How to Type Your Models Without Writing Everything Twice

How to type Mongoose schemas in TypeScript without duplicating interfaces, using InferSchemaType, HydratedDocument, and the populate() fix nobody explains.

Aug 17, 202615 min readZeeshan Tofiq

Mongoose 9 Migration Guide: What Actually Breaks in a Real MERN App

Upgrading to Mongoose 9? Here's what actually breaks in real MERN apps: pre-save hooks, plugins, TypeScript types, and how to fix each one.

Aug 16, 202612 min readZeeshan Tofiq

Kubernetes Swap Support: Should You Turn It On in 1.35?

Kubernetes swap went stable in 1.35. Here's how it actually works, when it helps, when it hurts, and how to configure LimitedSwap correctly.

Aug 2, 202612 min readZeeshan Tofiq

rust

Rust Async Traits Still Aren't Object-Safe: The Real Fixes

Async fn in traits still isn't dyn-compatible in Rust. Here are the three real workarounds (enum dispatch, async-trait, RPITIT) and when to use each one.

Jul 24, 202614 min readZeeshan Tofiq

Deno Desktop Tutorial: Build a Native App From TypeScript, No Electron or Rust

A hands-on build of a real app with Deno 2.9's deno desktop command: Deno.serve() integration, window.bind() calls, WebView vs CEF, and packaging for macOS, Windows, and Linux.

Jul 24, 202612 min readZeeshan Tofiq

Mercor Frontend Engineer Interview: How to Prepare for AI Model Training Jobs

Getting a Mercor frontend engineer interview? Here's what the React and Next.js coding round actually tests, and how to prepare in a weekend.

Jul 20, 202617 min readZeeshan Tofiq

Go 1.26 Goroutine Leak Detection: A Practical Guide

Go 1.26 ships a real goroutine leak profiler. Here's how to enable it, read the profile output, and catch leaks in production before OOMKilled does it for you.

Jul 18, 202613 min readZeeshan Tofiq

Claude Code Skill Not Triggering? Every Cause and the Fix (2026)

Your Claude Code skill isn't triggering and there's no error. Here's every cause: paths, YAML, descriptions, and the hidden character budget.

Jul 16, 202614 min readZeeshan Tofiq

Docker Compose to Podman Quadlet: A Practical Migration Guide

Convert a docker-compose.yml to Podman Quadlet files step by step, with a full example, rootless setup, and the daemon-reload gotchas that trip people up.

Jul 15, 202632 min readZeeshan Tofiq

Why Your TypeScript 7 Upgrade Broke ESLint, ts-jest, and ts-morph

TypeScript 7's native compiler breaks typescript-eslint, ts-jest, and ts-morph. Here's exactly why, and the side-by-side setup that fixes it.

Jul 14, 202611 min readZeeshan Tofiq

html css

CSS Anchor Positioning: Migrating shadcn/ui Off Radix

How to migrate shadcn/ui Popover and Tooltip from Radix UI to native CSS Anchor Positioning and the Popover API, with real before/after code.

Jul 12, 202619 min readZeeshan Tofiq

MCP Server Disconnected? Here's the Actual Fix (2026)

Your MCP server shows disconnected in Claude Desktop, Claude Code, or Cursor. Here's exactly why, with fixes for stdout pollution, paths, and env vars.

Jul 12, 202616 min readZeeshan Tofiq

programming

Senior Full Stack System Design Interview Questions: How to Architect the Whole System (2026)

How senior full stack developers should answer system design questions: a complete framework covering frontend, API, database, and deployment in one story.

Jul 9, 202618 min readZeeshan Tofiq

npm postinstall Attacks: How They Work in 2026

How npm postinstall hook attacks like Shai-Hulud actually work in 2026, and a practical checklist to protect your projects and CI/CD pipeline.

Jul 7, 202614 min readZeeshan Tofiq

backend

HTTP QUERY Method in Express and Node.js

How to actually implement the new HTTP QUERY method (RFC 10008) in Express and Node.js, with working code for a search endpoint, CORS, and a POST fallback.

Jul 7, 202613 min readZeeshan Tofiq

Claude Fable 5: What It Is and When to Use It

Fable 5 is Anthropic's most capable public model. What it excels at, how the safety fallback works, and when Opus 4.8 is still the better call.

Jul 4, 202613 min readZeeshan Tofiq

Temporal API in Node.js APIs: Storing, Serializing, and Returning Dates Correctly (2026)

How to store, serialize, and return JavaScript Temporal API types correctly in a Node.js REST API with PostgreSQL. Real Express code and examples, 2026.

Jul 2, 202613 min readZeeshan Tofiq

python

Python 3.14 t-Strings: 5 Patterns f-Strings Can't Do Safely

Python 3.14 t-strings return a Template object, not a string. Here are 5 real patterns: safe HTML, structured logging, SQL builders, LLM prompts, and i18n.

Jul 2, 202614 min readZeeshan Tofiq

Next.js middleware.ts to proxy.ts: What Changes

Next.js 16 renamed middleware.ts to proxy.ts, and it's not just a name change. Here's what the runtime switch means and how to migrate a real auth-check file.

Jul 1, 202613 min readZeeshan Tofiq

programming

45 OOP Interview Questions and Answers (2026)

45 OOP interview questions covering the four pillars, SOLID principles, and design patterns with real code in Java, Python, JavaScript, and C#. Updated for 2026

Jun 27, 202645 min readZeeshan Tofiq

programming

50 DSA Interview Questions and Answers (2026)

50 DSA interview questions covering arrays, linked lists, trees, graphs, dynamic programming, and the 8 coding patterns that cover most interview problems. Updated for 2026

Jun 27, 202642 min readZeeshan Tofiq

Git Worktrees for Parallel AI Coding Agents: The Complete 2026 Workflow

How to use Git worktrees to run multiple AI coding agents in parallel. Claude Code's worktree flag, common pitfalls, and a clear decision framework.

Jun 26, 202618 min readZeeshan Tofiq

Bun 1.3's Built-in SQL and Redis Clients: Do You Still Need pg, mysql2, and ioredis?

Bun 1.3 ships built-in Postgres, MySQL, SQLite, and Redis clients. Side-by-side code vs pg, mysql2, and ioredis, plus when migrating actually makes sense.

Jun 26, 202614 min readZeeshan Tofiq

40 Kubernetes Interview Questions and Answers (2026)

40 Kubernetes interview questions covering Pods, Deployments, networking, RBAC, and real troubleshooting scenarios like CrashLoopBackOff and OOMKilled. Updated for 2026.

Jun 26, 202640 min readZeeshan Tofiq

java

Project Valhalla in JDK 28: What Value Classes Actually Change

JEP 401 just landed in OpenJDK mainline. Here is how to try value classes in JDK 28, what scalarization actually does, and the null surprise nobody expects.

Jun 23, 202611 min readZeeshan Tofiq

dotnet

C# Union Types: Migrating from OneOf in .NET 11 (2026 Guide)

C# 15 native union types just shipped in .NET 11 preview. Here is how they compare to the OneOf library, what migration actually looks like, and the boxing tradeoff to know about.

Jun 23, 202626 min readZeeshan Tofiq

pg_durable: Durable Workflows in PostgreSQL vs Temporal and Cron+Queue

Microsoft's pg_durable brings durable workflow execution inside PostgreSQL. Here is the syntax, what it replaces, and an honest comparison against Temporal and cron+queue patterns.

Jun 23, 202629 min readZeeshan Tofiq

WordPress CDN Supply Chain Attack 2026: What Happened and How to Check Your Site

The OptinMonster, TrustPulse, and PushEngage supply chain attack (June 2026) hit 1.2M sites. Here's exactly how it worked, how to check if you were compromised, and how to recover.

Jun 21, 202616 min readZeeshan Tofiq

Migrate Next.js to TanStack Start: Practical Guide with Real Examples

How to migrate a Next.js app to TanStack Start: the two-PR strategy, route migration, replacing next/image, and setting up Nitro, with real production lessons from Railway and Inngest.

Jun 21, 202629 min readZeeshan Tofiq

Bumblebee Tutorial: Scan Your Dev Machine for Supply Chain Risks

How to install and use Bumblebee, Perplexity's open-source scanner for npm, MCP configs, and extensions. Real commands, scan profiles, and incident response setup.

Jun 21, 202624 min readZeeshan Tofiq

Source Maps Are Leaking Your Code: How to Stop It in Your npm Packages

Source maps with sourcesContent can leak your entire codebase. Learn how to disable them per bundler, audit with npm pack, and automate the check in CI.

Jun 21, 202617 min readZeeshan Tofiq

50 Cloud & DevOps Interview Questions and Answers (2026)

50 cloud and DevOps interview questions covering AWS Lambda, Docker, Microservices, API Gateway, S3, serverless, and Azure Entra ID. With code examples.

Jun 15, 202658 min readZeeshan Tofiq

TypeScript 7 Migration Guide: tsgo, Breaking Changes, Build Times

Migrate to TypeScript 7 (tsgo): install the beta, fix the 4 breaking changes, update tsconfig, and decide if upgrading now is worth it.

Jun 15, 202625 min readZeeshan Tofiq

backend

Hono.js Tutorial: REST API with Zod, JWT & Cloudflare Workers

Step-by-step Hono.js tutorial: routing, middleware, Zod validation, JWT auth, and deployment to Cloudflare Workers and Node.js. Working code throughout.

Jun 15, 202614 min readZeeshan Tofiq

40 SQL Interview Questions and Answers (2026)

40 SQL and relational database interview questions covering joins, indexes, ACID, window functions, CTEs, MySQL vs PostgreSQL, and query challenges.

Jun 14, 202647 min readZeeshan Tofiq

Caching Strategies Explained: CDN, Redis & DB Cache

A practical guide to caching strategies: browser cache, CDN, in-process memory, and Redis. Learn which layer to use, cache-aside patterns, and invalidation.

Jun 13, 202615 min readZeeshan Tofiq

GitHub Actions Tutorial: CI/CD from Push to Deploy (2026)

Learn GitHub Actions: write your first workflow, run tests automatically, use secrets safely, deploy via SSH, cache dependencies, and run matrix builds.

Jun 12, 202611 min readZeeshan Tofiq

GitHub Actions Security: 7 Misconfigurations to Avoid

The 7 GitHub Actions misconfigurations behind real supply chain attacks: weak GITHUB_TOKEN scope, pull_request_target, unpinned actions, script injection.

Jun 12, 202611 min readZeeshan Tofiq

42 NoSQL Database Interview Questions and Answers (2026)

42 NoSQL interview questions covering MongoDB, Redis, and DynamoDB: aggregation pipelines, data structures, GSI vs LSI, and CAP theorem. Updated for 2026.

Jun 10, 202651 min readZeeshan Tofiq

30 Next.js Interview Questions and Answers (2026)

30 Next.js interview questions with full answers: App Router, Server Components, use cache, PPR, Turbopack, and auth. Updated for Next.js 15 and 16.

Jun 8, 202638 min readZeeshan Tofiq

30 NestJS Interview Questions and Answers (2026)

30 NestJS interview questions with full answers: modules, DI, guards, pipes, interceptors, JWT auth, microservices, and testing. Updated for 2026.

Jun 8, 202631 min readZeeshan Tofiq

30 Node.js Interview Questions and Answers (2026)

30 Node.js interview questions with full answers: event loop, streams, clustering, worker threads, memory leaks, and security. Updated for 2026.

Jun 8, 202637 min readZeeshan Tofiq

Multi-Agent AI Coding Workflow: Step-by-Step (2026)

Build a 3-agent AI coding workflow with CrewAI and Python. One agent writes, one reviews, one writes tests. Full code included.

Jun 7, 202617 min readZeeshan Tofiq

React Fiber Architecture Explained: How React Renders UI

React Fiber is the engine behind every React render. Learn how it works: render phase, commit phase, Lanes, and double buffering, explained with analogies.

Jun 7, 202618 min readZeeshan Tofiq

Claude Code Cheatsheet: Commands, Hooks & Subagents

The complete Claude Code reference: every slash command, keyboard shortcut, hook, subagent, and CLAUDE.md tip, with real examples for developers.

Jun 6, 202614 min readZeeshan Tofiq

Next.js Dark Mode Without the Flash (Tailwind v4)

Add dark mode to your Next.js App Router app without the white flash. Complete guide covering next-themes, Tailwind CSS v4 setup, and Cloudflare Pages.

Jun 6, 202630 min readZeeshan Tofiq

tools

GitHub Copilot Token Billing: Real Cost by Workflow (2026)

GitHub Copilot switched to AI Credits billing June 1. Code completions stay free. Here's what chat, agent mode, and code review cost per workflow, and when to switch.

Jun 5, 202615 min readZeeshan Tofiq

python

How to Switch to uv: Replace pip, virtualenv, and Poetry in Your Python Project

uv replaces pip, virtualenv, and Poetry with a single fast binary. Step-by-step guide to migrating your existing Python project and setting up GitHub Actions CI.

Jun 4, 202625 min readZeeshan Tofiq

ARIA in React: Stop Using aria-label Wrong

Pages using ARIA average 41% more accessibility errors. Learn the correct ARIA patterns for React: icon buttons, modals, toasts, spinners, and tab panels.

Jun 1, 202614 min readZeeshan Tofiq

npm Scripts You're Probably Not Using (But Should Be)

pre/post hooks, cross-env, npm-run-all, argument passing, and built-in variables: the npm script patterns developers Google one at a time, in one place.

Jun 1, 202626 min readZeeshan Tofiq

How to Use Environment Variables in Next.js (Without Leaking Them to the Browser)

Learn how to use .env files in Next.js correctly. Understand NEXT_PUBLIC_, avoid common mistakes, and set variables in Vercel and Cloudflare.

May 30, 202615 min readZeeshan Tofiq

Husky + Prettier + lint-staged Setup for Next.js

Set up Husky v9, Prettier, and lint-staged in your Next.js project. Step-by-step guide covering pre-commit hooks with the correct 2026 config.

May 30, 202620 min readZeeshan Tofiq

How to Audit Your VS Code Extensions for Security

The GitHub breach happened through a VS Code extension. Here's how to check what you have installed and reduce your exposure in 10 minutes.

May 30, 202616 min readZeeshan Tofiq

TypeScript 7 (Project Corsa): What Next.js Devs Need to Know

TypeScript 7 rewrites the compiler in Go for 10x faster builds. Here's what it means for your Next.js project and what to do right now.

May 30, 202616 min readZeeshan Tofiq

html css

8 CSS :has() Patterns You'll Actually Use (2026)

CSS :has() is production-ready in every browser. Here are 8 real-world patterns: form states, sibling dimming, modal scroll-lock, and more.

May 30, 202615 min readZeeshan Tofiq

5 async/await Mistakes That Slow Your JavaScript Code

Sequential awaits, await in forEach, missing Promise.all: these 5 async/await mistakes silently slow your JavaScript. Here's how to spot and fix each one.

May 30, 202620 min readZeeshan Tofiq