Senior Software developer

Guildford
5 days ago
Create job alert

Senior / Experienced Software Developer
Location: Guildford (Hybrid – must be UK-based and within a two-hour commute)
Contract: Full-time, Permanent
Salary: £55,000 – £65,000 (depending on experience)
The Opportunity
An established UK technology company is expanding its Software Development Team and is looking for an experienced Senior Software Developer to help evolve a large-scale, enterprise-grade SIP platform and its associated REST APIs.
This is an excellent opportunity to work on complex, real-world systems in a collaborative, technically strong environment. You’ll contribute to the ongoing development of a mission-critical communications platform, build value-added services, and work with modern AI-driven integrations.
The organisation is known for its strong engineering culture, long-term customer partnerships, and commitment to professional development. You’ll be joining a supportive, innovation-led environment where your ideas and expertise will have a real impact.
Role Summary

  • Designing, developing, and enhancing an existing enterprise SIP platform and supporting services
  • Building new value-added services and capabilities around the core platform
  • Developing integrations with third-party systems, including AI-based voice recognition, transcription, and sentiment analysis services
  • Ensuring secure software design and development at both application and network levels
  • Analysing, troubleshooting, and resolving SIP/RTP and platform-level issues
  • Contributing to secure development processes, policies, and compliance with standards such as ISO 27001 and PCI-DSS
  • Collaborating closely with other developers and stakeholders to deliver high-quality, scalable solutions
    Essential Skills & Experience
  • SIP / VoIP and related protocols (SDP, RTP, RFC2833 / RFC4733, etc.)
  • Python or another object-oriented language (5+ years)
  • Object-oriented design principles
  • HTTP / RESTful APIs
  • Flask or Django, including Jinja, Pytest, SQLAlchemy, and Marshmallow
  • Secure systems design and development (software and network level)
  • SIP/RTP troubleshooting using tools such as Wireshark
  • Git / GitHub (or similar version control systems)
  • Docker containerisation
  • Linux (Ubuntu-based) environments
  • Full drviing licence with car due to the client's location
    Desirable Skills
  • FreeSWITCH (configuration and, ideally, source code)
  • C / C++ (for open-source troubleshooting or minor code changes)
  • Kamailio
  • Auth0 / OAuth 2.0
  • MongoDB and/or MySQL
  • CI/CD pipelines (e.g. GitHub Actions)
  • Kubernetes / ArgoCD
  • WebRTC
    Benefits
  • 24 days’ annual leave plus bank holidays
  • Pension, Life insurance, Private medical insurance
  • Birthday and volunteering day off
  • High street discount vouchers
    Thank you for taking the time to apply to OPR Resourcing Specialists. If your application is successful you will be contacted within 7 days. We apologise but due to the high volume of applications we receive we are unable to provide feedback on individual CV's.
    Regrettably, we are unable to offer Right to Work Sponsorship.
    If you do not currently have the Right to Work in the UK or will need additional support to extend your current Right to Work status, your application cannot be considered.
    Please note that by applying for the above job it will be understood that you accept our Terms of Business and Privacy Policy which can be found on our website on the page "Find A Job

Related Jobs

View all jobs

Senior Software Developer

Senior Software Developer

Senior Software Developer

Senior Software Engineer (SC Cleared)

Senior Software Engineer

Senior Developer

Subscribe to Future Tech Insights for the latest jobs & insights, direct to your inbox.

By subscribing, you agree to our privacy policy and terms of service.

Industry Insights

Discover insightful articles, industry insights, expert tips, and curated resources.

Maths for Cloud Jobs: The Only Topics You Actually Need (& How to Learn Them)

If you are applying for cloud computing jobs in the UK you might have noticed something frustrating: job descriptions rarely ask for “maths” directly yet interviews often drift into capacity, performance, reliability, cost or security trade-offs that are maths in practice. The good news is you do not need degree-level theory to be job-ready. For most roles like Cloud Engineer, DevOps Engineer, Platform Engineer, SRE, Cloud Architect, FinOps Analyst or Cloud Security Engineer you keep coming back to a small set of practical skills: Units, rates & back-of-the-envelope estimation (requests per second, throughput, latency, storage growth) Statistics for reliability & observability (percentiles, error rates, SLOs, error budgets) Capacity planning & queueing intuition (utilisation, saturation, Little’s Law) Cost modelling & optimisation (right-sizing, break-even thinking, cost per transaction) Trade-off reasoning under constraints (performance vs cost vs reliability) This guide explains exactly what to learn plus a 6-week plan & portfolio projects you can publish to prove it.

Neurodiversity in Cloud Computing Careers: Turning Different Thinking into a Superpower

Cloud computing sits at the heart of modern tech. Almost every digital product runs on someone’s cloud platform – from banking apps & streaming services to AI tools & online shops. Behind those platforms are teams of cloud engineers, architects, SREs, security specialists & more. These roles demand problem-solvers who can think in systems, spot patterns, stay calm under pressure & imagine better ways to build & run infrastructure. That makes cloud computing a natural fit for many neurodivergent people – including those with ADHD, autism & dyslexia. If you are neurodivergent & considering a cloud career, you might have heard messages like “you’re too distracted for engineering”, “too literal for stakeholder work” or “too disorganised for operations”. In reality, many traits that come with ADHD, autism & dyslexia are exactly what cloud teams need. This guide is written for cloud computing job seekers in the UK. We will cover: What neurodiversity means in a cloud context How ADHD, autism & dyslexia strengths map to cloud roles Practical workplace adjustments you can ask for under UK law How to talk about neurodivergence in applications & interviews By the end, you should have a clearer sense of where you might thrive in cloud computing – & how to turn “different thinking” into a professional superpower.

Cloud Computing Hiring Trends 2026: What to Watch Out For (For Job Seekers & Recruiters)

As we move into 2026, the cloud computing jobs market in the UK is shifting again. The era of “lift & shift everything to the cloud” is giving way to a more mature, cost-conscious & security-focused phase. Many organisations are tightening budgets, some are rationalising cloud spend, yet demand for strong cloud talent remains high – especially around multi-cloud, FinOps, cloud security, data platforms & AI on cloud. Vendors are racing to integrate generative AI into their offerings, enterprises are modernising legacy estates, & regulators are asking tougher questions about resilience, sovereignty & risk. At the same time, some roles are being automated or commoditised, & the bar for cloud roles keeps rising. Whether you are a cloud job seeker planning your next move, or a recruiter building cloud teams, understanding the key cloud computing hiring trends for 2026 will help you stay ahead.