Senior Developer

Title: Senior Developer 
Location: Wrexham 
Hours: 37.5 hours Monday to Friday

What we do:

We’re the leaders in outsourced calls, live chat and more, delivering brilliant conversations on behalf of businesses of all sizes. Fast-forward two decades and what started as a single, dedicated PA (who’s still with us today) looking after calls for a handful of local clients, is now a 1000-strong team working across two continents from our state-of-the-art UK headquarters in Wrexham, and our US office in Atlanta.

The role – Senior Developer – AI Agent Voice Assistant Platform:

Moneypenny’s AI voice agent is live in production, handling thousands of customer calls every day across the UK and US. 

We are seeking an experienced Senior Developer to help us scale faster. In this role, you will develop, maintain, and enhance Chinwag, the AI system that powers our voice agents. Your work will span voice processing, agent orchestration, task scheduling, and integrations with external systems and MCP servers.

This is an exciting opportunity to work on patent-pending technology at production scale, delivering real-world AI solutions that are used daily by our customers.

Responsibilities:

• Lead the design and development of scalable, reliable software that supports complex AI-driven product and business requirements
• Develop, enhance, and maintain Chinwag, our AI voice agent platform, ensuring performance, resilience, and scalability
• Contribute to systems covering voice processing, agent orchestration, task scheduling, and external integrations
• Review code and provide clear, constructive feedback to maintain high engineering standards
• Drive work to successful completion within the immediate team, ensuring quality and timely delivery
• Write and maintain automated tests using test-driven development practices to ensure code quality and coverage
• Integrate software with monitoring, alerting, and support tools
• Ensure applications operate effectively in their target production environments
• Write, review, and take ownership of technical documentation
• Lead troubleshooting and resolution of issues throughout the product lifecycle, including participation in out-of-hours incident support when required
• Participate in and, where appropriate, lead agile planning, estimation, and delivery activities
• Actively contribute to improving development practices, including pairing, code and documentation reviews, and continuous delivery
• Collaborate with product, project, and technical leads to design solutions and create clear, implementable specifications at feature and component levels
• Mentor and coach junior developers, providing technical leadership and guidance
• Stay current with emerging and existing technologies and help introduce them where they add value

Knowledge & Skills:

• Extensive experience building and maintaining large-scale, production-grade software in fast-paced environments with rapid release cycles
• Strong Python development experience, including designing robust, maintainable systems
• Experience working with AI-enabled or distributed systems in production environments
• Solid understanding of modern development and deployment toolchains, including IDEs, CI/CD pipelines, and monitoring solutions
• Strong problem-solving skills and the ability to work effectively across complex, interconnected systems

Tech Stack:

Python 3.11+ • FastAPI • asyncio • OpenAI • Docker • MongoDB • pytest • Git • Twilio • Deepgram • ElevenLabs • LiteLLM • Groq • LangChain • MCP servers • AWS/Azure • DataDog • SendGrid • ActivePieces

What’s included:

As a Senior Developer at our award-winning headquarters in Wrexham, you’ll enjoy welcoming, spacious, state-of-the-art offices, plus communal spaces including a treehouse – we like to do things differently around here! You’ll also benefit from:

• Permanent contract 
• 25 days annual leave plus bank holidays (pro rata)
• Mental health support (through our Employee Assistant Programme) with access to an on-site mental health counsellor
• Access to our wellbeing room to help enhance your physical and mental wellbeing
• Access to a 24/7 doctor line
• Subsidised meals
• Free on-site gym access
• And did we mention our epic parties? We know how to celebrate in style!