// npm init -y && npm install express
const express = require("express");
const app = express();

app.get("/", (req, res) => {
  res.send("Hello from Express");
});

app.listen(3000, () => console.log("http://localhost:3000"));

# pip install flask
from flask import Flask

app = Flask(__name__)

@app.get("/")
def home():
    return "Hello from Flask"

if __name__ == "__main__":
    app.run(debug=True, port=5000)

const express = require("express");
const app = express();
app.use(express.json());

const tasks = [{ id: 1, title: "Pick a backend" }];

app.get("/tasks", (req, res) => res.json(tasks));

app.get("/tasks/:id", (req, res) => {
  const task = tasks.find((t) => t.id === Number(req.params.id));
  if (!task) return res.status(404).json({ error: "not found" });
  res.json(task);
});

app.post("/tasks", (req, res) => {
  const title = (req.body.title || "").trim();
  if (!title) return res.status(400).json({ error: "title is required" });
  const task = { id: tasks.length + 1, title };
  tasks.push(task);
  res.status(201).json(task);
});

app.listen(3000);

from flask import Flask, request

app = Flask(__name__)
tasks = [{"id": 1, "title": "Pick a backend"}]

@app.get("/tasks")
def list_tasks():
    return tasks

@app.get("/tasks/<int:task_id>")
def get_task(task_id):
    task = next((t for t in tasks if t["id"] == task_id), None)
    if task is None:
        return {"error": "not found"}, 404
    return task

@app.post("/tasks")
def add_task():
    title = ((request.get_json(silent=True) or {}).get("title") or "").strip()
    if not title:
        return {"error": "title is required"}, 400
    task = {"id": len(tasks) + 1, "title": title}
    tasks.append(task)
    return task, 201

if __name__ == "__main__":
    app.run(debug=True)

const fs = require("fs/promises");

async function readConfig() {
  try {
    const text = await fs.readFile("config.json", "utf8");
    return JSON.parse(text);
  } catch (err) {
    console.error("Could not read config:", err.message);
    return {};
  }
}

readConfig().then((cfg) => console.log("Loaded", cfg));
console.log("This line runs before the file finishes loading");

# pip install flask scikit-learn joblib
from flask import Flask, request
import joblib

app = Flask(__name__)
model = joblib.load("model.joblib")   # a trained scikit-learn model

@app.post("/predict")
def predict():
    data = request.get_json(silent=True) or {}
    features = data.get("features")
    if not isinstance(features, list):
        return {"error": "features must be a list"}, 400
    return {"prediction": float(model.predict([features])[0])}

Do I already know JavaScript well?         Y → Node.js + Express
Do I already know Python well?             Y → Flask
Do I want React full stack roles?          Y → Node.js
Do I want data, ML or automation roles?    Y → Flask
I know neither?                            → Flask (gentler start), add JS later

Week 1: Language refresh (JS or Python), HTTP basics, JSON
Week 2: Routes, request bodies, status codes, validation
Week 3: Connect a database (SQLite/PostgreSQL), CRUD endpoints
Week 4: Error handling, simple tests, deploy, README

☐ GET list and GET by id
☐ POST with validation and 201 status
☐ PUT/PATCH and DELETE
☐ 400 and 404 errors return JSON messages
☐ Data stored in a real database
☐ README with example requests (curl)