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const { name } = user You've seen it in every React file. It just pulls name out of user into its own variable ✂️ Curly braces grab by name, square brackets grab by position. Defaults and renames 👇

GROUP BY in one picture 📊 Many rows in, one row per group out. Then COUNT and SUM tell you something about each group. Five orders become three customers. Learn it with a real database 👇

Answer: it logs "0102030" 🧩 The scores are strings. total starts as 0, then 0 + "10" turns into "010", and every pass after that sticks another string on the end. Turn each one into a number first and you get 60. Fix in the reply 👇

Find the bug 👀 You'd expect 60. What does this log, and why? Answer on Saturday. Drop your guess in the replies.

3/ Components run on the server by default, so you can fetch right inside them. Make it async, await the data and render it. No useEffect, no loading juggling for the first render.

2/ A new route is a new folder. app/about/page.tsx shows up at /about. The folder name is the URL.

1/ A page is just a file. Make app/page.tsx, export a component, and that's your home page at /. No router config.

One API that creates, reads, updates and deletes data, split into routers and saved to a JSON file so it keeps the data after a restart.

A POST route that checks what it's sent. Pydantic validates the request body, and you send a status code that matches what happened.

A route that returns JSON. A client asks for /books, your function runs, and FastAPI sends the list back.

What does the <T> in a TypeScript function actually do? It's a placeholder for a type. Pass in numbers, get a number back. Pass in strings, get a string. One function, and TypeScript still checks every call. Practice it in TypeScript Fundamentals 👇

Junior vs senior: the same function, written two ways. Both work on a normal cart. The difference isn't cleverness. The senior version plans for an empty cart and a missing qty. Which one would you rather debug? 🤔

How does a button know you clicked it? Short answer: addEventListener. You tell the browser which event to listen for, and which function to run when it happens. The full explainer, with code you can run 👇