Credits and licenses
Where the backend interview course came from, what we changed, and the licenses.
In short
This course used two openly licensed guides as outlines: which topics a backend interview covers and roughly how deep to go.
Every answer, exercise, hint, fact, code sample and diagram in this course is new and written by us. No text from either guide is used.
Both guides are published under the Creative Commons Attribution 4.0 International license (CC BY 4.0), which lets us adapt them as long as we credit them, link the license and say what we changed. That is what this page does.
Every Python sample was run on Python 3.13 and type-checked with mypy in strict mode, and every SQL sample was run on PostgreSQL 17. Samples that need a database ran against a real PostgreSQL 17 server.
The System Design Primer
The System Design Primer by Donne Martin, licensed under CC BY 4.0.
Copyright 2017 Donne Martin
Used for: Outline for the distributed systems, caching, performance and system design topics.
What we changed
- Used the topic list as an outline only and wrote every answer from scratch.
- Added runnable Python and PostgreSQL checks, exercises, hints and visualizers.
- Updated details to current tools (PostgreSQL 17, Redis 7, Kafka 4).
Adapted from "The System Design Primer" by Donne Martin, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Changes: used as a topic outline; all text, code and exercises here are new.
Zalando RESTful API and Event Guidelines
Zalando RESTful API and Event Guidelines by Zalando SE, licensed under CC BY 4.0.
Copyright Zalando SE
Used for: Outline for the API design topic: resources, methods, status codes, compatibility, pagination and events.
What we changed
- Used the guideline headings as an outline only and wrote every answer from scratch.
- Added exercises, hints, runnable code and quick facts.
- Framed rules as interview answers with trade-offs rather than as one company's requirements.
Adapted from the "RESTful API and Event Guidelines" by Zalando SE, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Changes: used as a topic outline; all text, code and exercises here are new.
Further reading
- Back-End Developer Interview Questions by Arialdo Martini (GPL-2.0). Read for topic coverage only; no text used.
- OWASP Cheat Sheet Series by OWASP Foundation (CC BY-SA 4.0). Recommended reading for the security and auth topics; no text used.
- Tech Interview Handbook by Yangshun Tay (MIT). Recommended reading for behavioral interviews; no text used.