We are looking for a research-minded Senior Security Penetration Tester who sits at the intersection of three disciplines: operational technology (OT/ICS) security, exploit development and zero-day discovery, and offensive testing of AI and agentic systems. This is not a scanner-driven role. You will break real industrial environments safely, write working exploits for vulnerabilities you find yourself, and attack LLM applications and autonomous agents the way a capable adversary would. You will deliver client engagements end-to-end, contribute original research to the client's zero-day program, and help build the AI-driven tooling that scales our offensive capability. The role suits someone who enjoys going deep on hard targets and can explain what they found to both engineers and executives. Responsibilities Plan and execute safety-first penetration tests of OT/ICS environments (water and wastewater, energy, manufacturing, building systems), including passive asset discovery, Purdue-model segmentation testing and IT-to-OT pivot analysis Assess PLCs, RTUs, HMIs, SCADA servers, historians and engineering workstations across major vendors (e.g., Rockwell/Allen-Bradley, Siemens, Schneider Electric) and SCADA platforms (e.g., VTScada, Ignition, AVEVA/Wonderware) Test industrial protocols such as Modbus/TCP, DNP3, EtherNet/IP/CIP, S7comm, OPC UA, BACnet and IEC 60870-5-104/61850 for authentication, integrity and logic-manipulation weaknesses Build and use lab or digital-twin replicas to validate attack paths before touching production; operate strictly within client-approved rules of engagement, change windows and safety constraints Map findings to ISA/IEC 62443, NIST SP 800-82 and MITRE ATT&CK for ICS, with remediation guidance that is realistic for plant operations Conduct vulnerability research on binaries, firmware, embedded/IoT devices, web applications and enterprise software using reverse engineering, source code review and fuzzing (coverage-guided, protocol-aware and grammar-based) Write reliable proof-of-concept and weaponized exploits for memory corruption (stack/heap overflows, use-after-free, type confusion), logic flaws and authentication bypass Attack LLM applications and agentic AI systems, assessing how models, retrieval, tools and permissions combine to create attack surface Contribute original research to the client's zero-day program and help build AI-driven tooling that scales offensive capability Deliver client engagements end to end and communicate findings clearly to both engineers and executives Requirements Bachelor's degree in Computer Science, Information Security, Electrical/Control Engineering or a related field, or equivalent practical experience 5+ years of hands-on penetration testing and offensive security experience, including significant depth in at least two of: OT/ICS security, exploit development/vulnerability research, and AI/LLM security Background in OT/ICS penetration testing on real industrial environments or high-fidelity labs, with a strong grasp of safety-first testing practices Showcase of exploit-writing ability, evidenced by original vulnerability research such as CVE credits, published advisories or exploits, conference talks, or high-level bug bounty/CTF results Hands-on experience testing LLM applications or agentic AI systems, with an understanding of how models, retrieval, tools and permissions combine to create attack surface Strong programming skills in Python and C/C++, with working knowledge of x86/x64 and ARM assembly; Bash/PowerShell required Proficiency with reverse engineering and debugging tools such as IDA Pro, Ghidra and Binary Ninja, alongside WinDbg and GDB with pwndbg/GEF Competency in fuzzers (AFL++, libFuzzer, boofuzz) and offensive tooling (Burp Suite, Metasploit, Nmap), as well as Wireshark with ICS dissectors and C2 frameworks such as Cobalt Strike or Sliver Familiarity with industry standards and frameworks, including OWASP Top 10, CVE/CWE and OSSTMM, along with NIST, MITRE ATT&CK, ISA/IEC 62443 and MITRE ATLAS Excellent written and spoken English; able to convey complex technical concepts to technical and non-technical audiences Based in Europe and eligible to work through EPAM; able to overlap with US business hours for client meetings, and available for occasional travel (e.g., on-site OT assessments) when required Nice to have Knowledge of Rust or Go Relevant offensive security certifications (considered a plus, not a substitute for demonstrated skill)
