USA | CoreWeave | Technical Phone Screen

Location
USA
Posted
17 Jan 2026
379 reads

Summary

I completed a technical phone screen for CoreWeave (formerly Weights and Biases) in USA, where I was tasked with designing a data filtering system based on complex search queries, including support for conditional expressions and equality comparisons.

How it went

Completed a technical phone screen for Weights and Biases (now part of CoreWeave).

Question

You're given data like this at Weights and Biases and a common operation is filtering for data you want based on your search query. For example:

data = [
  {'a': 2, 'duration': 20, 'val_acc': 0.9},
  {'b': 5, 'loss': 30, 'duration': 25}
]

condition = (duration > 22) AND (a > 1 OR b < 3)

Part 1: Basic filtering

Assume that a row of data is a set of key/value pairs where value is float
Support < and > comparisons

You don't have to worry about string parsing the condition as you can define the representation yourself

Part 2: Choice of

Pick one of:

  • Print the stringified condition expression based on your part 1 design
  • Suppport equality condition for strings, booleans, etc

I went with part 2 of adding equality condition, but also updated the < or > condition to attempt to convert both the data value and threshold value to float and if we fail, return false

Reflection

  • Chill interviewer
  • Interviewer didn't really engage in the "collaboration part of the design". Rather they gave me free reign over the design and just watched
  • Asking good clarifying questions to button up the scope helped me get a good handle on the problem

Questions asked (1)

  1. 01

    Data Filtering with Search Queries

    Data Structures & Algorithms

    You're given data like this at Weights and Biases and a common operation is filtering for data you want based on your search query. For example:

    data = [
      {'a': 2, 'duration': 20, 'val_acc': 0.9},
      {'b': 5, 'loss': 30, 'duration': 25}
    ]
    

    condition = (duration > 22) AND (a > 1 OR b < 3)

    Part 1: Basic filtering

    Assume that a row of data is a set of key/value pairs where value is float
    Support < and > comparisons

    You don't have to worry about string parsing the condition as you can define the representation yourself

    Part 2: Choice of

    Pick one of:

    • Print the stringified condition expression based on your part 1 design
    • Suppport equality condition for strings, booleans, etc

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