Uber - Frontend Engineer - Technical Phone Screen

Level: Frontend Engineer II

Education: Masters

Years of Experience (YOE): 7

Questions Asked:
Spreadsheet Cell Evaluation Problem:

Implement a simple Excel-like system that supports the following:

  • setCell(cellId, value)
  • readCell(cellId)

Where:

  • value can be either a number or a formula like “=A1 + B2”.
  • readCell(cellId) returns the computed value, including evaluating formulas that reference other cells.

Key Skills Tested:
• JavaScript classes and object modeling
• Expression parsing and dynamic evaluation
• Dependency tracking and formula recomputation
• Time and space complexity discussion

Was the Spreadsheet cell evaluation problem a OOP (javascript) or was it react UI?