How CrowdStrike Interviews in 2026: Process, Questions & What They Score

1. 01

   Encode and Decode Strings

   Length-prefix or escaping scheme to serialize a list of strings so delimiters inside strings still decode correctly.

2. 02

   Number of Islands

   Grid DFS or BFS flood fill (or union-find) to count connected components.

3. 03

   Time Based Key-Value Store

   Per-key timestamped history with binary search for the latest value at or before a given timestamp.

4. 04

   String Compression

   In-place array rewrite with two pointers, run-length encoding consecutive repeated characters.

5. 05

   Network Delay Time

   Shortest paths on a weighted directed graph using Dijkstra with a priority queue.

6. 06

   Is Subsequence

   Two-pointer scan checking characters appear in order, in linear time and constant space.

7. 07

   Number of Dice Rolls With Target Sum

   Dynamic programming over dice count and running sum, with modulo arithmetic on large counts.

8. 08

   Implement templated string replacement

   String parsing: find placeholders and substitute values from a map, handling missing keys.

9. 09

   Maximize the minimum value along a grid path

   Bottleneck path on a grid via max-heap Dijkstra, or binary search with BFS or union-find.

10. 10

    Implement a custom queue data structure with thread-safe operations to prevent race conditions during concurrent access.

    Concurrency: locks and condition variables for a blocking queue that avoids races and deadlock.

11. 11

    Implement a Risk-Score Priority DetectionStore With Put and GetNext in C++

    Data structure design: a heap-backed priority store with put and getNext operations, in C++.

12. 12

    Group log records by machine and return the busiest few, then handle the same input as an endless stream with limited memory.

    Hash-map counting and top-k with a heap, then a streaming variant under bounded memory.

13. 13

    Given a list of file paths and their associated threat scores, identify the top K most dangerous directories by aggregating scores from all files within them.

    Aggregate file scores up each directory prefix with a hash map or trie, then pick top K with a heap.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   Design a Log Parser

   Low-level design of a parser: class structure, pluggable log formats and handling of malformed lines.

2. 02

   Design a Rate Limiter

   Rate limiting design: token bucket or sliding window, per-client limits and shared counters at scale.

3. 03

   Design a log monitoring and alerting system

   Design of log ingestion, rule evaluation and notification, with alert latency and delivery as trade-offs.

4. 04

   Design a file upload and scanning report system

   Upload pipeline design: object storage, asynchronous scan workers, and storing and serving scan reports.

5. 05

   Design scalable worker pool for template jobs

   Job queue and worker pool design: scheduling, concurrency limits, retries and backpressure.

6. 06

   Design a system that ingests a very large stream of endpoint events and raises alerts within seconds.

   Streaming ingestion design: partitioning, event ordering, deduplication and backpressure with low alert latency.

7. 07

   Design a log aggregation service for 10,000 endpoints reporting 100,000 events per second.

   Throughput sizing for 100,000 events per second: batching, partitioning, storage and retention.

8. 08

   What would change if data volume increased 100x?

   Scalability reasoning: find the first bottleneck at 100x and respond with sharding, partitioning or tiering.

9. 09

   How would you test this in production?

   Safe rollout and observability: canaries, feature flags, metrics and rollback in production.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   Explain how EDR differs from traditional antivirus solutions.

   Security concepts: behavior and telemetry based detection and response versus signature based scanning.

2. 02

   How would you investigate a suspected breach? Walk me through your methodology.

   Incident response method: scoping, containment, evidence collection, timeline reconstruction and eradication.

3. 03

   Describe the MITRE ATT&CK framework and how you've used it.

   Threat modeling vocabulary: mapping adversary tactics and techniques to detections and hunts.

4. 04

   How would you detect lateral movement within a compromised network?

   Detection engineering: spotting abnormal logons, remote execution and credential use across hosts.

5. 05

   How would you prioritize alerts in a high-volume SOC environment?

   Triage reasoning: weighing severity, asset criticality, confidence and alert volume in a SOC.

Reported problems, listed so you know what to expect. Practice them in your own editor or on the platform you prefer; SupaCV's practice mode coaches how you talk through them.

1. 01

   Tell me about a time you handled a major production incident.

2. 02

   How did you convince a team to adopt a new technical direction?

3. 03

   Describe mentoring a junior engineer remotely.

4. 04

   Explain a difficult project and a colleague conflict.

5. 05

   How have you managed a dependency on another team when their timeline did not align with yours?

6. 06

   Tell me about a time you got something wrong.

7. 07

   How did you convince leadership to prioritize a security initiative?

8. 08

   Tell me about a time you asked for help early and avoided an outage.

9. 09

   How do you approach problems you've never seen before?

10. 10

    Why CrowdStrike specifically? What attracts you to our mission of stopping breaches?

11. 11

    Tell me about a time you worked under pressure to respond to a security incident.