A national law enforcement technical interception unit provides real-time telecommunications interception and technical support for judicial investigations, developing and operating specialised telecom solutions used in sensitive cases. This Senior Telecom Engineer role exists to provide Level 3 telecom expertise across mobile and VoIP systems, working on core network elements (EPC, 5GC), IMS/VoLTE and SIP-based voice services.
The mission
The team operates and enhances interception and monitoring platforms used by technical investigators, maintaining reliable handling of signalling and media across 2G/3G/4G/5G and VoIP environments. Your work supports lawful interception workflows, operator interfaces and the validation of new telecom features; the technical landscape includes core network elements (EPC, 5GC), IMS, SIP, VoLTE, routing and security controls.
On a day-to-day basis you will act as the escalated technical owner for complex incidents and deployments, combining on-call Level 3 support with testing and deploying new interception capabilities. You will collaborate with network operators, software teams and investigators to validate solutions, contribute test plans and documentation, and help mature support processes for the broader technical interception capability, which is operationally deployable across the country and in Europe when needed.
Your responsibilities
- Lead resolution of escalated incidents to restore critical telecom services and reduce mean time to repair, using packet-level debugging and signalling analysis.
- Validate, test and deploy telecom features and interception integrations, ensuring changes meet legal and operational requirements.
- Design and improve monitoring, alerting and proactive checks for SIP, IMS, EPC and 5GC components to increase system availability.
- Collaborate with network operators and internal software teams to troubleshoot roaming, interconnect and routing issues affecting capture and decoding.
- Produce and maintain clear technical documentation, test plans and runbooks so support colleagues can follow validated procedures.
- Mentor junior engineers and contribute to continuous improvement of support workflows and ticketing practices.
Your profile
Essential skills
- Proven experience as a telecom engineer with 7+ years in mobile network or operator environments.
- Deep knowledge of mobile network architecture: 2G/3G/4G/5G, Core Network (EPC, 5GC), IMS and VoLTE.
- Strong practical experience with VoIP and SIP signalling, RTP media handling and related routing.
- Experience with roaming, interconnect, lawful interception concepts and security considerations.
- Skilled in troubleshooting at packet and signalling level, familiar with capture and analysis tools.
- Comfortable working in sensitive environments, able to maintain discretion and professional conduct.
Languages
- French, C1 or Dutch, C1 (fluency in one national language required).
- The other national language (French or Dutch), at least B2.
- English, B2 for technical documentation and cross-team communication.
Education
- Degree in Telecommunications, Computer Science, Network Engineering or Cybersecurity, or equivalent experience.
A TOP SECRET security clearance is required for this position and must be obtainable according to national legislation.