Beginner guides.
No background assumed. What a database, a domain or an environment variable actually is, and how to get an app you built with AI online and keep it there.
131 posts · page 4 of 5
Merge Conflicts Explained: What They Are and How to Fix Them
CONFLICT (content): Merge conflict in app.js looks alarming, but it's Git asking you a simple question. Why conflicts happen, how to read the <<<<<<< and >>>>>>> markers, how to resolve one in VS Code or with an AI tool, how to back out safely, and how to avoid most of them.
Linters and Formatters Explained: ESLint, Prettier, Biome, and Ruff
A formatter makes code look consistent; a linter catches likely bugs. What each does, the common tools for JavaScript and Python, how to run them automatically on save and before every commit, and why they matter even more when an AI is writing the code.
I Leaked an API Key. What Now? A Step-by-Step Response
You pushed a .env file to GitHub, pasted a key in a screenshot, or found your secret key in your app's frontend code. What to do in the next ten minutes, the next hour, and the next day — revoke, rotate, check for abuse, clean up — and how to stop it happening again.
How to Launch Your First App: A Beginner's Launch Checklist
Your app works. Now what? A practical launch plan for first-time builders: the pre-launch checks, where to find your first users, how to launch on Product Hunt, Reddit, and Hacker News without getting ignored or banned, and what to watch in the first week.
How to Know When Your App Is Down (Before Your Users Tell You)
Most small apps find out about outages from an annoyed email. Three cheap layers — an uptime check, error tracking, and logs you can search — mean you hear first, and usually know why. What each one does, how to set it up in an afternoon, and how to avoid alerts you'll learn to ignore.
How to Install Claude Code on Mac, Windows, and Linux
A step-by-step guide to installing Claude Code: the recommended native installer, Homebrew, WinGet, and npm; which account you need; signing in; checking it works with claude doctor; updating; and fixing the install problems beginners hit most often.
HTTP Status Codes Explained: 200, 301, 404, 500 and the Rest
Every response from a server starts with a three-digit number that says how it went. What the 2xx, 3xx, 4xx, and 5xx families mean, the dozen codes you'll actually meet, what each one tells you about where a bug lives, and which ones your own API should return.
HTML, CSS, and JavaScript: What Each One Does
Every web page is built from three languages with three different jobs: HTML for structure, CSS for looks, JavaScript for behaviour. What each one is, how they fit together, what they look like, and how much of each you need to understand to steer an AI tool.
How to Read an Error Message (and Fix Things Faster)
Error messages look like walls of gibberish, but they usually tell you exactly what went wrong and where. How to find the one line that matters, what common errors actually mean, where to look when there's no error at all, and what to give an AI so it can fix it first time.
How to Read a Diff: Reviewing What Your AI Tool Changed
A diff shows exactly what changed in your code: red lines removed, green lines added. How to read unified and side-by-side diffs, what the @@ lines mean, where to look them up in Git, VS Code, and GitHub, and a quick review routine for AI-generated changes.
How to Write Good Prompts for AI Coding Tools
The difference between an AI tool that builds what you want and one that goes in circles is usually the prompt. A simple structure for asking — goal, context, constraints, and how you'll know it's done — with before-and-after examples you can copy.
How Much Does It Cost to Run an App? A Realistic Monthly Budget
Hosting, database, domain, email, AI usage, storage, and the tools around them. What each costs for a small app, what's free, where surprise bills come from, and three example budgets — from a side project to a small business with paying customers.
How to Keep API Keys Out of an AI-Built App
AI-generated code hardcodes API keys all the time — and 'put it in an environment variable' isn't enough if the variable ends up in the browser. Which keys are safe to expose, which never are, and how to fix a key that's already leaked.
How to Hand Off an AI-Built App to a Client
Freelancers and agencies are shipping client apps faster than ever with AI. The handoff is where projects go wrong: accounts in the wrong name, no documentation, and an open-ended support expectation. A checklist for handing over cleanly — and keeping the relationship profitable.
GraphQL vs REST: What's the Difference?
REST gives you many endpoints that each return a fixed shape; GraphQL gives you one endpoint where the client asks for exactly the fields it wants. How each works, over-fetching and under-fetching, the costs GraphQL adds, and why most small apps should start with REST.
What Is .gitignore? Keeping Secrets and Junk Out of Git
A .gitignore file tells Git which files never to save — your .env secrets, node_modules, build output, and OS clutter. How it works, the pattern syntax, a starter file for JavaScript projects, and what to do if you already committed something you shouldn't have.
How Much Does GitHub Codespaces Actually Cost?
Codespaces bills by the hour for compute and by the GB-month for storage, with a free allowance on personal accounts. How the meter works, three worked examples from occasional to full-time use, and the settings that stop the bill surprising you.
Git Branches Explained for Beginners
A branch is a safe parallel copy of your project where you can try something without touching the working version. What branches are, the commands to create, switch, and merge them, a simple workflow for solo builders, and why branches matter when an AI agent is editing your code.
Git and GitHub for Beginners: The Undo Button for Your Whole Project
If you build with AI, git is the single most useful thing you can learn — it lets you save your project at good moments and go back when the AI breaks something. What git and GitHub are, the six commands you need, and a simple routine to follow.
GDPR Basics for App Builders: What a Small App Actually Needs
If anyone in the EU or UK uses your app, GDPR probably applies. What personal data is, the principles in plain English, lawful bases, the rights users have (access, deletion), what to do about third-party services and data breaches, and a practical checklist for a small app. Not legal advice.
Frontend vs Backend: What's the Difference?
Every app has a part that runs in your browser and a part that runs on a server. Knowing which is which explains why secret keys leak, why some apps need a server and others don't, and what your AI tool actually built. A plain-English guide with a restaurant analogy that actually holds up.
Form Validation Explained: Client-Side, Server-Side, and Why You Need Both
Validation checks that what users type makes sense before you save it. The difference between browser-side and server-side validation, why only the server's counts for security, built-in HTML validation, sharing rules with a schema, and writing error messages people understand.
File Paths Explained: Absolute, Relative, and Why 'File Not Found' Happens
Cannot find module './components/Button'? ENOENT: no such file or directory? Most of the time it's a path problem. How file paths work on Mac, Linux, and Windows, absolute vs relative paths, ./ and ../, the working directory, case sensitivity, and import aliases like @/.
What Is an Environment Variable? .env Files Explained
Environment variables are how an app gets its settings and secrets — database passwords, API keys, the site's URL — without writing them into the code. What they are, how .env files work, why they must never reach GitHub, and the prefix that quietly makes a 'secret' public.