Senior Telephony & SIP Systems Engineer (Remote)

Senior Telephony & SIP Systems Engineer (Remote)
Portalegre
Portalegre, Portalegre District, Portugal

We're looking for a Senior Telephony & SIP Engineer to join a
- impact,
- time freelance project (3 months, fully remote) for a growing tech company building modern, reliable,
- time voice systems.

What You'll Do

• Design and maintain Vo
  IP systems based on SIP/RTP/SRTP.
• Work with Asterisk, Free
  SWITCH, Open
  SIPS or Kamailio.
• Build
  - time media services in Go or Python (Fast
  API).
• Integrate call events and audio streams with Fast
  API backends and Next. js frontends.
• Operate cloud infrastructure on AWS + Kubernetes (EKS) using Terraform.
• Monitor and troubleshoot SIP traffic using Wireshark, sngrep, tcpdump.
• Implement security best practices: TLS/SRTP, fraud prevention, SIP hardening.
• Collaborate with teams on integrations with Twilio, Telnyx, Signal
  Wire, CRMs, IVRs, etc.

Must-Have Requirements

• 5+ years working with Vo
  IP, SIP, RTP, media servers
• Hands-on experience with Asterisk / Free
  SWITCH
• Strong knowledge of networking (VLANs, Qo
  S, VPN, DNS, NAT traversal, STUN/TURN/ICE)
• Experience building
  - time systems in Go or Python (Fast
  API)
• Solid Linux and scripting background (Bash/Python)
• Experience with AWS, Kubernetes (EKS), Terraform
• Proficient using SIP diagnostics tools
• English: full professional proficiency

Nice to Have

• Vo
  IP/SIP certifications, CCNA/CCNP, RHCE
• Web
  RTC and UCaa
  S experience
• High-availability voice architectures
• Docker, Ansible, SBCs

Why This Project

• 3-month,
  - time freelance engagement
• 100% remote
• Modern infrastructure: AWS + EKS + Terraform
• High autonomy and direct production impact
• Technical challenges with
  - time media and
  - latency systems