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Stripe·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
Jun 2026

Summary

Stripe coding screen for a software engineer role. The problem was a weighted field-matching exercise, find all users whose similarity score against a target user exceeds some threshold by summing weights for matching fields.

Questions Asked (1)

Q1

You have a list of user records where each field has an associated weight. Given a target user ID and a threshold, return all user IDs whose total weight of matching fields with the target user exceeds that threshold.

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

Took me a minute to realize they literally just wanted a flat field-by-field comparison, no fuzzy matching, no recursion, just iterate users, compare each field, accumulate weight if it matches, check against threshold.

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AI HintsAI Generated

Suggested Approach

Clarify the problem constraints and assumptions first, then propose an efficient algorithm that computes weighted similarity between the target user and all others, filtering by the threshold. Discuss trade-offs between time and space complexity, and consider optimizations like indexing or early termination.

Pro tip: Mention that in a real system like Stripe, you'd likely precompute or index weighted similarities for scalability, and discuss how to handle dynamic weight updates or large user bases.

1. Clarify requirements and constraints

Ask about the size of the user list, number of fields, weight distribution, threshold range, and whether weights are static or dynamic. Confirm the definition of 'matching fields' (e.g., exact match, similarity).

2. Define the similarity metric

Explain that for each user, you compute the sum of weights of fields that match the target user's corresponding fields. This yields a weighted similarity score.

3. Propose a baseline algorithm

Iterate through all users, compute the weighted sum by comparing fields, and collect those exceeding the threshold. Analyze time complexity: O(N * F) where N is number of users and F is number of fields.

4. Discuss optimizations and trade-offs

Consider indexing fields or using inverted indices to quickly find users sharing fields with the target. Discuss space-time trade-offs, early termination if partial sum exceeds threshold, and parallelization for large datasets.

5. Handle edge cases and scalability

Address cases like no matches, threshold zero, missing fields, and dynamic updates. For scalability, mention precomputation, caching, or approximate methods if exact results are not required.

Key Points to Mention

  • Time and space complexity analysis of the proposed solution
  • Trade-offs between exact and approximate matching, and between precomputation and on-the-fly computation
  • Use of appropriate data structures (e.g., hash maps, inverted indices) to optimize field comparisons
  • Handling of dynamic weights or user data updates
  • Scalability considerations for large user bases (e.g., distributed processing, indexing)
  • Edge cases such as empty lists, zero threshold, and missing fields

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