AlgoFoxGet AlgoFox App

CoursesSystem Design Foundations

Scale and Performance

The cache and its hit rate, the edge and what belongs on it, read replicas and the lag they carry, and the partition key that spreads the load or concentrates it.

Lessons
6
Exercises
35
Minutes
37

Start Cache What Repeats

  1. 1

    Cache What Repeats

    After this lesson you can turn a hit rate into origin load, decide what is worth caching, choose between a TTL and invalidation, and spot the cache key that serves the wrong answer.

    DebugMultiple choiceShort answer
    5 exercises
    5 min
  2. 2

    The Edge and the CDN

    After this lesson you can say what belongs on a content delivery network, why distance is latency, and how to split a page so the shared part is served from the edge and the personal part is not.

    Fill blankMultiple choiceShort answerTap
    5 exercises
    5 min
  3. 3

    Read Replicas and Their Lag

    After this lesson you can size replicas for a read load, say what replication lag does to a user who just wrote, and route the reads that must see the write.

    DebugMultiple choiceShort answerTrace
    5 exercises
    6 min
  4. 4

    Partitions and the Hot Key

    After this lesson you can split a table across machines by a key that spreads the load, predict where a bad key concentrates it, and handle the one key that is hot no matter what.

    DebugMultiple choiceShort answerTap
    5 exercises
    6 min
  5. 5

    Checkpoint: Scale and PerformanceCheckpoint

    Caches, the edge, replicas and partitions for a system you have not seen before.

    DebugMultiple choiceShort answerTap
    7 exercises
    6 min
  6. 6

    Boss: The Content FeedBoss

    One design carried from the ask to the incident: the question, the estimate, the feed contract, where the reads go, a viral post, the post that vanished from its own author's feed, the revised read path, and the tradeoff you have to defend.

    Code orderMultiple choiceShort answerTapTrace
    8 exercises
    9 min