Me postulé en línea. Acudí a una entrevista en Citadel
Entrevista
I didn't make it past the OA. The OA was automatically sent. The OA was very hard. It was only two questions but it was super hard. Apply at your own risk.
Experiencia positiva
Entrevista difícil
Solicitud
Acudí a una entrevista en Citadel (New York, NY) en ene 2026
Entrevista
1. Algorithmic clarity
Can you identify the core pattern quickly?
Think: prefix sums, sliding windows, graph traversal, greedy with proof, DP state design.2. Mathematical reasoning
They love problems where correctness requires a proof or invariant.
Example: why a greedy choice works, why a hash remainder trick detects divisibility.
3. Performance instincts
You’re expected to reason about:
Time complexity under constraints
Memory vs speed tradeoffs
Edge cases at scale (10⁶–10⁹ inputs)
This is finance engineering. Latency is money.
Preguntas de entrevista [1]
Pregunta 1
1. Prefix sum + hashing
Why? O(1) lookups under heavy data flow.
Examples:
Subarray sum divisible by k
Longest equal 0/1 subarray
Detect arbitrage-like patterns
What they care about:
Do you understand why equal remainders imply divisible differences?