Bastion Talent is retained by a specialist telecom and mobile-network security firm to fill this role. Our client works with mobile operators, governments and large enterprises to secure critical network infrastructure. 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.
About the client
Our client is an independent, research-led telecom and mobile-network security specialist. For over a decade they have helped mobile operators, regulators, governments and cellular-powered enterprises secure critical network infrastructure across the full protocol stack — from legacy 2G/3G SS7 and SIGTRAN through 4G Diameter and GTP to IMS/VoLTE and 5G core, RAN and NFV. Their work spans offensive security (audits, penetration testing, red teaming) and defensive products (intrusion detection, attack-surface management and vulnerability intelligence), and their researchers contribute to international standards and industry groups. The team is lean, senior and fully distributed.
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)