Senior Python Developer
Location: Guildford
Hybrid Working (one day per month required onsite)
Contract: Full-time, Permanent
Salary: £55,000 - £65,000 (DOE)

About the Company

My client is an award-winning, privately-owned value-added reseller and systems integrator based in Guildford, Surrey. Established in 1984, they work with leading vendors such as 8x8, BT, Calabrio, Five9, Fortinet, Microsoft, Mitel, and Zoom to deliver innovative, connected solutions.

More than just a reseller, my client develops in-house software and offers professional services, focusing on business communications, contact centres, unified communications, networking, AI, automation, and systems integration. They are committed to delivering value, mitigating risks, and building trusted relationships with their customers.

My client fosters a supportive, innovative, and customer-focused culture, offering extensive learning and career development opportunities. Joining them means being part of a team dedicated to professional growth and technical excellence.

The Role

My client is seeking a Senior Python Developer to join their software development team. You will work on expanding and improving their enterprise-level SIP platform and associated REST APIs.

Key responsibilities include:

• Designing, developing, and enhancing their SIP platform and associated services using Python

• Building value-added services and integrations, including AI-based voice recognition, transcription, and sentiment analysis

• Ensuring secure software design and development at all levels

• Troubleshooting and resolving SIP/RTP and platform-related issues

• Contributing to secure development processes and policies, ensuring compliance with standards such as ISO27001 and PCI-DSS

Essential Skills & Experience

• 5+ years of Python or other object-oriented programming experience

• Strong understanding of OO design and software development principles

• Experience with HTTP/REST APIs

• Familiarity with Flask or Django, Jinja, Pytest, SQLAlchemy, Marshmallow

• Secure software and systems design (software & network level)

• Understanding of SIP/VoIP protocols (SDP, RTP, RFC2833/4733) is highly desirable

• Experience with Wireshark for SIP/RTP troubleshooting

• Git/GitHub or equivalent version control

• Docker containerisation experience

• Linux (Ubuntu) systems experience

• Excellent written and verbal communication skills for both technical and non-technical audiences

Desirable/Bonus Skills

• FreeSWITCH configuration and/or source code knowledge

• C/C++ for open-source troubleshooting

• Kamailio configuration experience

• Auth0/OAuth 2.0

• MongoDB or MySQL

• GitHub Actions CI/CD or similar

• ArgoCD/Kubernetes

• WebRTC

Benefits

• 24 days' holiday plus bank holidays

• Pension and life insurance

• Private Medical Insurance

• Birthday and volunteering day off

• Cycle to Work Scheme

• High street discounts

Due to the volume of applications received for positions, it will not be possible to respond to all applications and only applicants who are considered suitable for interview will be contacted.

Proactive Appointments Limited operates as an employment agency and employment business and is an equal opportunities organisation

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