Java Developer; SIP​/VoIP

Java Developer (SIP/VoIP) Contract - Paying up to £367 Per Day, Inside IR35, Based in Ipswich, Hybrid Working, Contract until March 2027, To Start ASAP

Your new role

We're looking for an experienced Voice Services Developer to join a team delivering next generation voice and conversational AI platforms. You'll develop and support SIP-based voice services, manage Free SWITCH/Asterisk environments, and integrate advanced Speech AI technologies across AWS, Azure and GCP.

Key Responsibilities:

• Develop and maintain SIP services using Java, JAIN SLEE and SIP Servlets
• Configure and support Free SWITCH and/or Asterisk platforms
• Integrate STT, TTS and NLP capabilities into live voice solutions
• Deploy and support applications across AWS, Azure and GCP
• Troubleshoot VoIP, call quality and network issues using tools such as Wireshark and sngrep
• Collaborate with architecture and Dev Ops teams to deliver scalable AI-driven voice solutions

What you'll need to succeed

• Strong commercial Java development experience
• Expertise in JAIN SLEE and SIP Servlet frameworks
• Experience with Free SWITCH or Asterisk
• Strong understanding of SIP, RTP/RTCP and SDP
• Experience integrating cloud-based speech services (AWS, Azure or GCP)
• Multi-cloud deployment experience

  Desirable:

• Metaswitch Rhi...