All posts.
Every EasySpawn article, newest first — deploying AI-built apps, Claude Code, databases, security, and the infrastructure underneath.
422 posts · page 8 of 18
How KVM Virtualization Works: The Isolation Behind Cloud Servers
Most cloud VMs run on KVM. How hardware-assisted virtualization works — VT-x/AMD-V, the VMM, virtio, two-level page tables — what a VM boundary protects against compared with containers, the remaining risks (side channels, noisy neighbours, steal time), and what shared vs dedicated vCPUs mean.
"JavaScript Heap Out of Memory": Why It Happens and How to Fix It
FATAL ERROR: Reached heap limit — JavaScript heap out of memory. What Node's heap limit is, why builds and servers hit it, how to raise it safely with --max-old-space-size, when the real problem is a memory leak, and the difference from exit code 137.
What Is IDOR? The Security Bug Where Users Can See Each Other's Data
IDOR (insecure direct object reference) is when changing an ID in a URL shows you someone else's data. How it happens, why it's the most common serious bug in AI-built apps, how to test for it in five minutes, and the one-line habit that prevents it.
Idempotency Keys: Making POST Requests Safe to Retry
A timeout on "create payment" — did it go through or not? Idempotency keys let clients retry safely without double-charging. How the Idempotency-Key header works, a Postgres-backed implementation, handling concurrent duplicates, fingerprint mismatches, expiry, and what to store.
Horizontal vs Vertical Scaling: How Apps Handle More Users
Vertical scaling means a bigger server; horizontal scaling means more servers. How each works, what load balancers do, why databases are the hard part, what has to change in your app to scale out, and why most small apps should scale up first.
Health Check Endpoints: What /health Should (and Shouldn't) Check
A health check endpoint tells load balancers, orchestrators and monitors whether your app can serve traffic. Liveness vs readiness, what to check and what not to, response formats, timeouts, security, and examples for Express, Next.js and Docker.
Graceful Shutdown in Node.js: Handling SIGTERM Without Dropping Requests
Every deploy and restart sends your Node.js app SIGTERM. How to shut down gracefully: stop accepting traffic, fail readiness, finish in-flight requests, close keep-alive connections, drain workers, close database pools — plus the Docker PID 1 and npm start signal traps.
Git Stash Explained: Save Unfinished Work Without Committing
git stash puts your uncommitted changes aside so you can switch branches or pull, then brings them back later. How stash, pop, apply and list work, stashing untracked files, naming stashes, recovering a dropped stash, and when a quick commit is better.
Git Rebase vs Merge: What's the Difference and When to Use Each
Merge and rebase both bring changes from one branch into another, but they shape history differently. How each works, fast-forward and squash merges, interactive rebase, the golden rule of rebasing, resolving conflicts during a rebase, and a sensible team policy.
How to Get Your Website on Google: A Beginner's Step-by-Step Guide
Your new site doesn't show up on Google. How to check whether it's indexed, set up Google Search Console, verify your domain, submit a sitemap, request indexing, fix the common blockers, and what to realistically expect in the first weeks.
Error Monitoring for Beginners: Find Out About Bugs Before Your Users Tell You
Error monitoring tools catch crashes in your app — frontend and backend — and alert you with the stack trace and context. What error tracking is, how tools like Sentry work, what to set up first, source maps, privacy, and avoiding alert fatigue.
ERR_TOO_MANY_REDIRECTS: What Causes It and How to Fix It (Including Cloudflare)
"This page isn't working — redirected you too many times." The usual causes of a redirect loop — Cloudflare's Flexible SSL mode, conflicting www rules, an app that doesn't know it's behind a proxy, and login loops — and how to find and fix each.
Encryption at Rest vs in Transit: What's the Difference?
Encryption in transit protects data moving across a network; encryption at rest protects data stored on disk. What each one protects against, what it doesn't, how HTTPS, disk encryption and field-level encryption fit together, and what a small app actually needs.
Do You Need Kubernetes? (Probably Not Yet — Here's How to Tell)
Kubernetes runs containers across many machines and is everywhere in job ads. What it actually does, what it costs to operate, the signs you might need it, and the simpler options that serve almost every small app and startup better.
DNS Propagation Explained: Why Domain Changes Take Time (and How to Speed Them Up)
You changed a DNS record and your site still points to the old place. What "DNS propagation" really is (caching, not spreading), how TTL controls the wait, why nameserver changes take longest, how to check from different places, and how to flush your own cache.
Database Seeding Explained: Test Data That Makes Development Easier
Seeding fills your database with starter data so the app is usable the moment you run it. What seed data is, the difference between reference data and sample data, how to write an idempotent seed script, using Faker, and how to keep seeds away from production.
How to Add Dark Mode to Your Website (CSS, Tailwind, and a Toggle)
Add dark mode the right way: follow the system setting with prefers-color-scheme, organise colours with CSS variables, use Tailwind's dark: variant, add a toggle that remembers the choice, and avoid the white flash on page load.
Cron Expressions Explained: What "*/5 * * * *" Means (With Examples)
A beginner's guide to cron syntax: the five fields, special characters, a cheat sheet of common schedules (every 5 minutes, daily at 9am, weekdays), the time zone and overlap gotchas, and where cron expressions show up — crontab, GitHub Actions, and app schedulers.
Core Web Vitals Explained: LCP, INP, and CLS for Beginners
Google's Core Web Vitals measure how fast, responsive and stable your pages feel. What LCP, INP and CLS mean, the thresholds for "good", how to check your scores, the difference between lab and field data, and the usual fixes.
Context Engineering for Coding Agents: Beyond Prompt Engineering
Context engineering is designing everything an agent sees — instructions, tools, files, history — not just the prompt. Why context is a finite budget, context rot, just-in-time retrieval, progressive disclosure with skills, note-taking and compaction, subagents, and how to apply it to Claude Code.
How to Add a Contact Form to Your Website (With or Without a Backend)
Four ways to make a contact form actually deliver messages — form services, your host's built-in forms, Google Forms, and your own backend route — plus how to stop spam and why you should never put an email API key in frontend code.
Codespaces vs Coder vs Ona: Cloud Development Environments Compared (2026)
An honest comparison of the main cloud development environments in 2026 — GitHub Codespaces, Coder, Ona (formerly Gitpod) and DevPod-style tools — by who runs them, pricing model, environment definition, persistence, and what each is actually for.
Claude Code on the Web, Desktop, or Terminal: Which One Should You Use?
Claude Code runs in a terminal, a desktop app, VS Code, and in the cloud at claude.ai/code. Where each version runs, what happens when you close your laptop, how --cloud and --teleport move work between them, and the limits of cloud sessions.
Claude Code in VS Code: Extension vs Terminal, Explained
Claude Code has a VS Code extension with a chat panel, inline diffs and @-mentions, and a terminal CLI with every command. How to install the extension, what each one can do, the PATH gotcha, and when to use which.