cloudpatterns.appClassroomKatasWhiteboardBlog
Interview LineLesson

Data model: from endpoints to keys

Five endpoints are on the board. Turn them into entities and relationships, list the queries they run, pick a store that serves those queries — and name the key behind each hot read before anyone asks about scale.

14 minMediumStation: Data model

Members lesson

Membership isn’t open yet. The free lessons are open — 19 of them.

Start a free lessonSee the path
  1. Back-of-the-envelope estimates
  2. API design
  3. Data model
  4. High-level design
  5. Design it: a URL shortener
Interview Line — where this lesson sits

What you'll be able to do

  1. 1Explain how the API's resources become entities, attributes and relationships (one-to-many, many-to-many), and where each relationship lives as keys.
  2. 2Choose a store — relational, a key-based NoSQL family, object storage for the bytes — from the access patterns and consistency needs, and justify it in one sentence.
  3. 3Predict which key or index serves each hot query, which query would have to ask every shard, and when copying data for a hot read is worth the extra writes.

Inside the lesson

steps
11
questions
15
simulations
0

More on the Interview Line

  1. Interview & rubric: 45 minutes, no answer keyOpen13 min
  2. Requirements: ask what changes the designMembers12 min
  3. Back-of-the-envelope: find the number that mattersMembers12 min
  4. API design: one line per requirementMembers12 min
  5. High-level design: every box answers to the boardMembers14 min