Cristian-Gheorghe Cretan

Work Experience

Software Engineer, CrowdStrike — BucharestMarch 2024 – Present

• Co-designed a multi-bucket re-architecture of the malware-sample storage platform (~30 PB across 3 clouds, ~600 TB/month ingest); owned the detailed technical design, cost/retention research, and full implementation in Go, Cassandra, and S3.
• Designed retention and deduplication levers worth ~$1–1.3M/year against a ~$2.8M/year storage baseline; built the storage-location registry, per-bucket TTL retention, and priority-ordered multi-read with zero-downtime legacy fallback.
• Cut latency ~80% in a production service by reworking its concurrency model and optimizing execution paths under sustained load.
• Cut the Cassandra cluster 60% on a ~2–3M req/s lookup service with a Bloom filter in Redis, since ~80% of lookups were misses.
• Saved ~$230K/year in infrastructure cost by right-sizing a service's resource usage through dynamic scaling and hot-path optimization.

Threat Researcher, CrowdStrike — BucharestSeptember 2022 – March 2024

• Initiated and built a Go service automating ingestion and analysis of file hashes, producing probabilistic true/false-positive assessments.
• Developed adversarial-emulation tooling in C++, C#, and Python for detection testing.

Threat Analyst Intern, CrowdStrike — BucharestJuly – September 2022

• Built a Python parser for Invoke-Obfuscation variants and tested each against Falcon to validate detection coverage.

Software Engineer Intern, Keysight Technologies — BucharestJune – September 2021

• Built a client-server PoC in C over the H2O library to exercise HTTP/3 performance and reliability.

Undergraduate Teaching Assistant, Politehnica University of Bucharest2019 – 2023

• Taught labs and built study materials for Operating Systems and Computer Architecture / Assembly Language.

Projects

GPU Parallel Hash Table (CUDA)

• Built a GPU-accelerated hash table with dynamic resizing tuned for VRAM utilization; documented a performance analysis on large datasets.

On-demand ELF Loader (C)

• Implemented an on-demand ELF loader that maps program segments lazily and services page faults through a custom SIGSEGV handler over UNIX system calls.

Education

B.Sc. in Computer Science and Engineering2018 – 2022

Faculty of Automatic Control and Computer Science, Politehnica University of Bucharest. GPA 3.64 / 4.

Relevant coursework: Parallel and Distributed Algorithms, Local Networks, Operating Systems, Numerical Methods, Data Structures, Assembly Language, Object-Oriented Programming, Algorithm Design, Programming Paradigms, Communication Protocols.

Achievements

• Qualified for the preliminary Romanian National Team for ECSC (European Cybersecurity Challenge), 2020.