Principal Software Engineer

develop; Peterborough; Hybrid; GBP 90,000 - 110,000; Full time

Benefits offered by this job

5% annual bonus

Car salary sacrifice scheme

25 days holiday

Job summary

develop is seeking a Principal Software Engineer to lead architecture and deliver AI-driven, cloud-native services. This senior, hands-on role focuses on distributed systems, security, observability and scalable APIs, with a bias toward independent technical decision-making.

Based in Peterborough with hybrid working, you will mentor a small team of engineers across .NET and Python, drive technical standards, and influence product direction while delivering enterprise-scale production systems.

Qualifications

• Senior, hands-on role focused on architecture and AI integration.
• Designs cloud-native services and distributed systems.
• Defines architecture standards and ensures security and observability.
• Collaborates with product, UX and AI specialists to solve customer problems.
• Provides technical leadership and mentoring within a small team.

Responsibilities

• Design cloud-native services and distributed systems.
• Develop LLM integrations and AI workflows.
• Build scalable REST and GraphQL APIs.
• Define architecture and engineering standards.
• Improve security, observability and resilience across services.
• Collaborate with product, UX and AI specialists to solve real customer problems.
• Provide technical leadership and mentoring within a small, highly experienced team.

Skills

Architectural leadership

Independent executor

Strong communication

Tools

C# / .NET

Python

REST APIs

GraphQL

LLM APIs

Job description

Principal Software Engineer | Up to £100,000 + bonus | Hybrid in Peterborough

I’m working with a global enterprise software organisation that is investing heavily in its AI and cloud engineering capability. Their specialist innovation team is growing and they’re looking for a Principal Software Engineer to help take AI-driven products from concept through to enterprise-scale production.

This is a senior, hands-on engineering role focused on architecture, distributed systems, cloud services and AI integration. It’s ideal for someone who enjoys solving complex technical problems and influencing engineering direction, rather than managing large teams.

Package:

• Competitive salary DOE
• 5% annual bonus
• Car salary sacrifice scheme
• 25 days holiday

What you’ll be doing:

• Designing and building cloud-native services and distributed systems
• Developing LLM integrations and agentic AI workflows
• Building scalable REST and GraphQL APIs
• Defining architecture and engineering standards
• Improving security, observability and resilience across services
• Collaborating with product, UX and AI specialists to solve real customer problems
• Providing technical leadership and mentoring within a small, highly experienced team
• C# / .NET
• Python
• REST APIs & GraphQL
• LLM APIs and AI-assisted development tooling

The team works across both .NET and Python, so strong experience in both would be ideal.

What they’re looking for:

• Previous experience as a Principal Engineer, Lead Engineer or Software Architect
• Strong architectural judgement and systems design skills
• Deep understanding of distributed systems and cloud architecture
• Ability to work independently and drive technical decisions
• Strong communication and technical leadership skills

Why this role stands out:

You’ll be joining a small R&D-style engineering team (currently 5 engineers) with plans to double in size over the next few months. The environment offers:

• High autonomy
• Minimal bureaucracy
• Exposure to modern AI technologies
• Real influence over technical direction
• The opportunity to build features that will be rolled out across a large global software platform

The interview process is typically completed within 2–3 weeks, and the team is happy to wait for the right person if you’re serving a notice period.