Principal Software Developer

ONYX Insight; Nottingham; On-site; GBP 60,000 - 100,000; Full time

Job summary

An innovative technology organization in the renewable energy sector is seeking a Principal Software Developer. This role combines technical expertise with leadership, focusing on building high-quality software solutions using modern C# .NET and React. You'll be responsible for driving technical excellence, mentoring teams, and shaping the future of technology. Join a forward-thinking company that values collaboration and innovation, and play a key role in delivering impactful software that optimizes energy production worldwide. This is a unique opportunity to contribute to a sustainable future while advancing your career in a dynamic environment.

Qualifications

• 5+ years of experience in commercial software development using modern C# .NET.
• At least 2 years of hands-on experience with React and frontend development.
• Strong understanding of scalable, secure application design and micro-services architecture.

Responsibilities

• Lead the design, development, and deployment of features across backend and frontend systems.
• Provide technical guidance and mentorship to developers, encouraging best practices.
• Influence system architecture and contribute to long-term technology strategy.

Skills

C# .NET

React

Microservices Architecture

Cloud Platforms (AWS)

Agile Methodologies

Database Management (PostgreSQL)

CI/CD Pipelines

Technical Leadership

Collaboration Skills

Job description

The Role

We’re looking for a Principal Software Developer who is passionate about building high-quality, scalable software and driving technical excellence across teams. This is a hands-on role that combines deep technical expertise with architectural leadership. You'll work across the full stack—primarily with modern C# .NET and React—delivering robust solutions that underpin our core platforms and products.

In this role, you’ll take ownership of critical systems, guide technical decisions, and help shape the future of our technology landscape. You'll collaborate closely with engineers, product managers, and stakeholders to deliver impactful software that meets real-world needs.

Key Responsibilities:

• Architect and Develop: Lead the design, development, and deployment of features across backend and frontend systems.

• Mentor and Collaborate: Provide technical guidance and mentorship to developers, encouraging best practices and knowledge sharing.
• Drive Innovation: Work cross-functionally to design and deliver intuitive, high-performance solutions.
• Shape Technical Direction: Influence system architecture and contribute to long-term technology strategy.
• Ensure Code Quality: Write clean, scalable, and maintainable code using modern C# .NET (6–9) and React.
• Champion DevOps: Support CI/CD pipelines and infrastructure automation in partnership with platform engineers.

Ideally, you’ll have/be:

• 5+ years of experience in commercial software development using modern C# .NET.
• At least 2 years of hands-on experience with React and frontend development.
• A proven track record in leading technical initiatives or owning system architecture.
• Strong understanding of scalable, secure application design and micro-services architecture.
• Experience working with cloud platforms (preferably AWS).
• Proficiency with relational databases, ideally PostgreSQL.
• Familiarity with Agile methodologies and modern software delivery practices.
• Strong collaboration and communication skills.
• A proactive, solution-oriented mindset and a focus on delivering value.

About ONYX

ONYX Insight is a growing technology and engineering organisation in the renewable energy sector. Our vision is to build a more efficient future by becoming the world’s most innovative provider of predictive technology solutions. Our advanced sensing, software and analytics combined with our engineering experience are deployed on wind turbines around the world to maximise production and make turbines more reliable for longer, optimising energy production.

ONYX Insight is part of the Macquarie Group. Macquarie is a global financial services group operating in 34 markets in asset management, leasing and asset financing, market access, commodity trading, renewables development, specialist advisory services, capital raising and principal investment. The diversity of the Macquarie Group operations combined with a strong capital position and robust risk management framework has contributed to a 54 year-record of unbroken profitability.

For any further information, or to understand our products and services better, please feel free to look through our website: https://onyxinsight.com/

ONYX Insight are an equal opportunity employer and value diversity at our company. We do not discriminate based on race, religion, colour, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.