For students

How Apps Really Work

Auth, databases, storage, schedules, security, and the limits behind them. Each idea, then the real thing.

9 lessons102 minInsight Project · Backend Project

  1. 01·Concept

    What happens when you click

    DNS, TLS, servers, and the round trip behind every page.

  2. 02·Concept

    Sessions and tokens

    How an app remembers who you are between clicks, and what can go wrong.

  3. 03·Hands-on

    Social login with OAuth

    What happens when someone clicks "Continue with Google", then turn it on for real.

  4. 04·Concept

    Databases and row-level security

    Tables, keys, and rules that decide who sees which row.

  5. 05·Concept

    Files, storage, and CDNs

    Why files live apart from data, and signed URLs.

  6. 06·Concept

    Schedules and background jobs

    Cron, retries, and work that should not block a click.

  7. 07·Concept

    Attacks and defenses

    Injection, bots, brute force, and what a WAF blocks.

  8. 08·Concept

    Why limits exist

    Rate limits, quotas, and what they protect.

  9. 09·Capstone

    Capstone: a secured app

    Social login, a database change, and a private file, verified in one project.

  10. Final exam

    20 questions · 30 min · 80% to pass

    Finish every lesson first