Sigma Computing

Sigma Computing, a B2B SaaS analytics startup, utilizes a practical, collaborative first-round interview rather than standard algorithmic puzzles. The challenge involves implementing a backend for a spreadsheet tool similar to Google Sheets, characterized by a finite number of columns but infinite rows. Part 1: Basic Functionality The implementation requires the following core methods: * get_cell(row, col): Retrieves the value at specific coordinates. * set_cell(row, col, value): Updates a cell at specific coordinates. * print_firstn_rows(n): Outputs the top N rows of the dataset. Part 2: Formula Logic The system must support formula cells similar to standard spreadsheet functions. The implementation focuses specifically on an ADD operation (e.g., =ADD(C7, D4)). A critical component of this section is demonstrating robust testing for edge cases, specifically the detection and handling of circular dependencies (formula cycles). Part 3: Schema Modifications and Optimization Follow-up discussions focus on extending the system and code quality: * Designing logic for add_column() and delete_column() to modify the schema dynamically. * Refactoring for code cleanliness and removing redundant logic. Success in this interview relies on strong foundational coding skills and proficiency in a familiar programming language.