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Aeonea·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
Jul 2026

Summary

Had a technical screen at Aeonea for a software engineer role. It was basically one meaty coding question about tennis scoring, which sounds simple but has enough edge cases to trip you up if you're not careful.

Questions Asked (1)

Q1

Design and implement a tennis game scoring function. Given a stream of points won by player A or B, output the current score after each point in standard tennis notation, handling the full 0/15/30/40 progression, Deuce, Advantage, and Game win with the correct two-point lead rule. Walk through your data structures and update logic, then trace through a specific example sequence.

Algorithms & Data StructuresSystem Design
Author's notes

I thought I had this nailed in the first two minutes and then completely fumbled the Deuce/Advantage transitions.

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AI HintsAI Generated

Suggested Approach

Start by clarifying requirements and edge cases, then propose a clean state-based solution using two counters and a score mapping, and finally walk through the logic with a concrete example. Emphasize the two-point lead rule at deuce and how to detect game win.

Pro tip: Mention that you would write unit tests for critical sequences like deuce, advantage, and win-by-two, and discuss how the solution could be extended to tiebreaks or sets.

1. Clarify Requirements

Confirm input format (stream of 'A' or 'B'), output format (score after each point), and rules: standard scoring, deuce, advantage, win by two. Ask about tiebreak or set integration if relevant.

2. Design Data Structures

Use two integer counters for points won by each player. Maintain a mapping from 0,1,2,3 to '0','15','30','40'. For deuce/advantage, track the difference in points.

3. Define Update Logic

After each point, increment the winner's counter. If both >=3, handle deuce/advantage: if scores equal, 'Deuce'; if one leads by 1, 'Advantage <player>'; if leads by 2, game won. Otherwise, output mapped scores.

4. Trace Example

Walk through a sample sequence (e.g., A, A, B, A, B, B, A, A) showing scores after each point, including deuce and advantage transitions.

5. Discuss Edge Cases and Testing

Mention handling of invalid inputs, game already won, and how to test with unit tests covering deuce, advantage, and win-by-two scenarios.

Key Points to Mention

  • Mapping of points to tennis terms: 0, 15, 30, 40
  • Deuce condition: both players have at least 3 points and scores are equal
  • Advantage condition: one player leads by 1 after deuce
  • Game win condition: lead by at least 2 points when both have >=3 points, or when a player has 4 points and the other has <=2
  • Time and space complexity: O(n) time, O(1) space
  • Potential extensions: tiebreak scoring, sets, and match play

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.