BlackRock : QE Role Interview Questions

1. Write search_list to find a target in a linked list (nodes as dicts with value/next). Handle empty lists.

Twist: Optimize for cycle detection or recursive reversal.

2. Sum all digits in a floating-point string (e.g., "123.45" → 1+2+3+4+5=15).

Follow-up: Process streaming data with memory limits.

3. Given two rectangles (8 coordinates), write rectangle_overlap returning True/False.

Edge Case: Partially overlapping edges or nested rectangles.

4. Find users with <3 orders or <$500 total spend using JOINs and aggregates.

Testing perspective: Validate query results against corrupted test data.

5. Mirror a binary tree.

6. Implement in-order iterator with next()/hasNext().

7. Design tests for a payment API with OAuth2. Include idempotency checks and rate-limiting.

Expectation: RestAssured/Postman examples + boundary cases (e.g., expired tokens).

8. How would you reduce flakiness in UI tests for a trading platform with dynamic data?

Answer: Dockerized test envs, explicit waits, and AI anomaly detection.

9. Build a Jenkins pipeline for nightly regression tests. Include failure alerts and retry mechanisms.

10. How would you handle a dispute with developers over bug severity before a release?

11. Your team has 48 hours before a major release. What do you automate vs. manually test?