Java Developer

Salary: £45,000 - 70,000 per year

Requirements:

• Strong commercial Java development experience
• Experience with SIP, VoIP, RTP/RTCP and SDP
• Knowledge of JAIN SLEE and/or SIP Servlet frameworks
• Experience with FreeSWITCH or Asterisk
• Cloud experience across AWS, Azure or GCP
• Strong troubleshooting skills within telecoms or voice environments
• Docker and Kubernetes
• WebRTC
• Telecoms security protocols including TLS and SRTP
• Metaswitch Rhino SLEE or Oracle OCCAS experience

Responsibilities:

• Developing and enhancing SIP-based voice applications using Java
• Working with JAIN SLEE and SIP Servlet frameworks
• Supporting and integrating voice platforms including FreeSWITCH and Asterisk
• Deploying and supporting solutions across AWS, Azure and GCP
• Integrating Speech-to-Text, Text-to-Speech and AI-driven voice services
• Troubleshooting voice quality, call routing and network performance issues

Technologies:

• AI
• AWS
• Asterisk
• Azure
• Cloud
• Docker
• GCP
• Java
• Kubernetes
• Network
• Oracle
• Security

More:

We are a leading telecoms company seeking an experienced Java Developer to join our team delivering next-generation voice and communications platforms. This is a 6 month contract role based in Ipswich with a hybrid working arrangement and is inside IR35. You will work on large-scale telecoms services, cloud technologies and AI-powered voice solutions in a dynamic environment.

last updated 34 week of 2026