ChallengeGenerate matching shard id

time to read 1 min | 118 words

Here is something that came up that I liked as task to handle in a job interview. We have the following function, generating a shard id from a document key:

There is a need to create a new document that must reside on the same shard as another document. The task is to write a function that would generate that id.

For example:

  • Key to match: users/71
  • Document id to modify: orders/654

The result can be: orders/654-22261 or orders/654-vaueaa

In other words, both orders/654-vaueaa and users/71 will have the same shard.

I like this because it is very easy to explain and has simple coding requirements. But it allows to go deep into several different fields of knowledge to understand the candidate’s solution.

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