Bastion Talent is retained by a specialist cybersecurity firm working in critical infrastructure to fill this role. Our client works with large organisations — operators, governments and enterprises — to find and fix serious security weaknesses. The client’s identity is shared with shortlisted candidates under NDA.
Engagement & location
This position is fully remote within Europe (CET overlap preferred). Unless otherwise stated, it can be structured either as a freelance / contract engagement or as full-time employment — whichever suits you.
Rate
Indicative budget: €200–300 per man-day (for freelance / contract engagements).
About the client
Our client is a specialist cybersecurity firm and a recognised leader in offensive security for critical infrastructure. They help large organisations — operators, governments and major enterprises — find and fix serious weaknesses in the systems that keep essential services running, pairing hands-on security assessment with their own detection and analysis tooling. The team is small, highly technical and fully distributed across Europe.
The role
Senior IMS / SIP telecom engineer with security experience (or a strong security interest). You will stand up EPC / IMS and RAN test beds, then assess and harden IMS and VoLTE infrastructure for the client’s customers.
Key responsibilities
- Set up EPC / IMS and RAN test beds and lab networks for research.
- Run security assessments, audits and red-team penetration tests on telecom infrastructure, preferably remotely on customer premises.
- Find vulnerabilities across operation & maintenance, signalling and user-plane interfaces.
- Build proofs of concept to demonstrate findings.
- Propose, develop and implement mitigations; present reports to customers.
- Feed field experience back into product improvement; collaborate on secure system design.
What we’re looking for
- Deep understanding of IMS / SIP and its security weaknesses (SS7, SIGTRAN, Diameter, LTE, GTP-C a strong plus).
- Degree in Telecommunications, Computer Science or a related field.
- Experience with telecom core-network security and intrusion detection.
- Proficiency in C/C++, Python or Java.
- Familiarity with vulnerability-assessment tools and methodology.
- Excellent analytical and problem-solving skills.
- Fluent English (mandatory); French optional.
Hiring process
- Intro call (10–20 min)
- Manager call (30 min)
- Capability exercise
- Leadership call (30 min)