Coding Signals

The point of interviews is for interviewers to extract signals from certain candidate behaviors. In coding interviews, the signals can be broadly classified into the following categories: Problem Solving, Technical Competency, Testing, and Communication.

When interviewers take down interview feedback, these are likely what is on their feedback sheet.

Problem solving

Understanding the problem

• 👍 Understood the key aspects of the problem quickly
• 👎 Had difficulty in understanding the key aspects of the problem

Solution/approach

• 👍 Approached the problem in a systematic and logical manner
• 👎 Did not demonstrate a logical thought process for approaching the problem

Improving the solution

• 👍 Suggested a more efficient solution when prompted, or proactively coming up with a better solution
• 👎 Had difficulty in coming up with a more efficient solution even after being prompted

Trade-offs analysis

• 👍 Explained the trade-offs of different approaches clearly and correctly
• 👎 Failed to describe trade-offs of different approaches

Hinting

• 👍 Did not require any major hints
• 👎 Needed plenty of hints

Technical competency

Speed

• 👍 Quickly implemented a working solution
• 👎 Was not able to complete the solution

Correctness/Accuracy

• 👍 Implemented the solution correctly (e.g., working solution, minimal bugs)
• 👎 Unable to correctly implement a solution (e.g., non-working solution, incorrect logic, and/or serious bugs)

Complexity analysis

• 👍 Able to determine the algorithmic time and space complexity
• 👎 Was not able to determine the algorithmic time and space complexity (explain why TC came up with such an answer)

Mastery of chosen programming language

• 👍 Demonstrated mastery of the chosen programming language
• 👎 Does not seem to be familiar with the chosen programming language

Implementation

• 👍 Implementation was clean and straightforward
• 👎 Implementation was unnecessarily complex and/or messy

Coding style

• 👍 Coding style was neat (proper indentation, spacing and no bad practices)
• 👎 Coding style was messy (inconsistent indentation, weird spacings, etc)

Testing

Common cases

• 👍 Tested their code against various typical cases
• 👎 Failed to test the code against typical cases

Corner cases

• 👍 Found and handled corner/edge cases
• 👎 Failed to consider corner/edge cases

Self-correction

• 👍 Identified and corrected bugs in the code (where applicable)
• 👎 Was not able to discover and fix bugs even after being prompted

Communication

Clarify problem

• 👍 Appropriately asked good, clarifying questions about the problem
• 👎 Failed to confirm understanding/ask appropriate questions

Communicating approach

• 👍 Able to explain overall approach, technical terms and acronyms (where applicable)
• 👎 Failed to effectively explain overall approach, technical terms and acronyms (where applicable)

Explains while coding

• 👍 Explains what the code is doing while coding, especially for parts which aren't obvious
• 👎 Keeps silent during coding, or just reading out the code without much explanation