Engineering Fundamentals for Coding Interviews

Testing, system design, REST APIs, databases and complexity: short theory, quick checks, then a timed test.

21 short lessons, each with one check question and an instant explanation. Then a 15-question test in 20 minutes, in the format of a real online assessment.

• Testing

  Types of tests, Test doubles: stub, mock, fake, spy, The test pyramid and TDD, Flaky tests and coverage

  4 lessons

• System design fundamentals

  Vertical vs horizontal scaling, Load balancing, Caching, CDNs, Replication and sharding, CAP and consistency, Message queues, Rate limiting

  8 lessons

• REST APIs and microservices

  HTTP methods and idempotency, Status codes, Pagination, Retries, backoff and circuit breakers, Microservices basics

  5 lessons

• Databases

  Indexes, Transactions and ACID, SQL vs NoSQL

  3 lessons

• Data structures and complexity

  Big-O of common operations

  1 lesson