TEST & CERTIFICATION ENGINEER - VOIP (HYBRID)

Portuguese company hires for hybrid work

Working Model: Hybrid (60% remote; 40% in person)

Seniority: Mid

Location: Lisbon, Portugal

Language Requirements: Portuguese (minimum C2) / English (C1)

Sector: Telco

Instructions: Please send your CVs in English and make sure to include all skills and experience that match the requirements of the opportunity. This will significantly increase your chances of success.

We are seeking a T&C System Engineer to join a dynamic engineering and technology team based in Lisbon, working in a hybrid model (60% remote, 40% on-site). In this role, you will be responsible for testing, validating, and certifying VoIP solutions in telecom operator environments, ensuring technical compliance, system performance, and service readiness.

Mandatory Requirements

• Proven experience in testing and validating VoIP solutions within telecom operator environments.
• In-depth knowledge of signaling and media protocols such as SIP, RTP, and SDP.
• Familiarity with IMS architectures and softswitch platforms.
• Ability to design and execute functional, regression, and integration test plans.
• Proficiency with traffic analysis and testing tools (e.g., Wireshark, SIPP, tcpdump).
• Solid understanding of IP networking fundamentals, including routing, switching, DNS, NAT, and firewalls.
• Experience in analyzing Call Detail Records (CDRs) and integrating them with billing systems.
• Hands-on experience with vendor certification and homologation processes in telecom operator settings.
• Skilled in creating clear and concise technical documentation in both English and Portuguese.
• Analytical mindset with strong attention to detail and the ability to work independently in troubleshooting scenarios.
  
  

Key Responsibilities

• Conduct certification and acceptance testing of VoIP equipment and solutions (e.g., ATAs, gateways, IP phones, SBCs).
• Ensure compliance with operator technical specifications and interoperability standards.
• Reproduce, analyze, and document defects; collaborate with internal teams and external vendors to drive resolution.
• Participate in technical discussions and coordination meetings with engineering, operations, and support teams.
• Prepare detailed validation reports and deliver technical recommendations for go-live readiness.
• Support testing activities in staging environments and assist with pilot deployments when required.
• Maintain and continuously update testing documentation and repositories.
  
  

Nice to Have

• Experience with test automation tools and frameworks (e.g., Python, Robot Framework, Jenkins).
• Knowledge of mobile voice technologies such as VoLTE and VoWiFi, and their integration with 4G/5G networks.
• Relevant industry certifications (e.g., SIP, networking, VoIP).
• Familiarity with structured software testing methodologies and best practices.
  
  

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