Have you had experience working with user authentication systems?

Yes, experience with user authentication systems often includes implementing mechanisms such as:

• Login and registration using a password
• Using tokens (e.g., JWT) for sessions
• OAuth 2.0 for authorization via third-party services (Google, Facebook)
• Two-factor authentication

In Python, libraries and frameworks like Django with its built-in authentication system or Flask with extensions like Flask-Login are commonly used.

An example of simple authentication with Flask-Login:

from flask import Flask, request, redirect, url_for
from flask_login import LoginManager, UserMixin, login_user, login_required, logout_user

app = Flask(__name__)
app.secret_key = 'secret'
login_manager = LoginManager()
login_manager.init_app(app)

class User(UserMixin):
    def __init__(self, id):
        self.id = id

users = {'user1': {'password': 'pass1'}}

@login_manager.user_loader
def load_user(user_id):
    return User(user_id)

@app.route('/login', methods=['POST'])
def login():
    username = request.form['username']
    password = request.form['password']
    if username in users and users[username]['password'] == password:
        user = User(username)
        login_user(user)
        return redirect(url_for('protected'))
    return 'Invalid credentials', 401

@app.route('/protected')
@login_required
def protected():
    return 'Logged in successfully'

@app.route('/logout')
@login_required
def logout():
    logout_user()
    return 'Logged out'

if __name__ == '__main__':
    app.run()