Skip to main content
This guide walks you through the fastest way to get value from this knowledge base. Whether you are preparing for a backend engineering interview, deepening your understanding of a specific system, or building a habit of structured technical note-taking, the steps below show you how to orient yourself and start moving.
1

Choose your learning path

Pick the path that matches your current focus. The tabs below give you a recommended reading order for four common engineering profiles. You do not need to read everything — go deep on what matters most right now and return to other areas as you need them.
2

Use the note template

As you work through topics, use the lightweight technical note template to record what you learn. The template structures your understanding into seven sections: background, phenomenon, root cause analysis, solution comparison, practical advice, references, and a one-line summary. Writing notes this way makes the knowledge stick.
3

Go deep on a topic

Each page covers one focused concept. Read the background to understand why the topic matters, study the principle analysis to understand how it works, and check solution comparisons to understand the trade-offs. The practical advice section gives you rules of thumb you can apply immediately.
4

Apply the interview prep

Once you have built depth on a topic, practice explaining it. Review the Interview Guide, the Networking Q&A, and the Database Q&A to see how topics appear in practice. The goal is not just to know the answer, but to explain it clearly and connect it to real experience.

​
Learning Paths

Start with the concepts most likely to come up in interviews and production incidents, then build toward advanced internals.
  1. Redis — Understand cache avalanche, breakdown, and penetration. Learn the five data types and when to use each.
  2. MySQL — Learn how B+ tree indexes work, read EXPLAIN output, and understand MVCC and transaction isolation.
  3. Kafka — Producer delivery guarantees, consumer group offset management, and Kafka vs RabbitMQ tradeoffs.
  4. Elasticsearch — Inverted index internals, query DSL, and when to use ES instead of MySQL.
  5. Distributed Systems — Distributed locks, CAP theorem, and reliability patterns in practice.
  6. Database Interview Q&A — Review common interview questions with structured answers.