Principal Engineer

IRIS Software Group is one of the UK's largest privately held software companies, trusted by 100,000+ businesses, schools and accountancy firms to keep their operations running. Our software pays 1 in 6 UK employees, supports over 12,000 schools, and is relied on by 91 of the top 100 UK accountancy firms.

We're a Great Place to Work® certified employer, recognised for our commitment to well-being, inclusion and development - and we're growing fast.

As a Principal Engineer, you will be a senior technical leader responsible for shaping the architecture, engineering standards, and technical direction of our products. This is a highly hands-on role where you will lead from the front, working closely with engineering teams to deliver new features, integrations, platform enhancements, technical debt reduction initiatives, and high-quality customer outcomes.

You will collaborate with Product, Architecture, DevOps, Support, and other stakeholders across the business to ensure solutions are scalable, secure, and maintainable. Alongside driving technical excellence, you will mentor engineers, champion modern software development practices, and help teams continuously improve how they build and deliver software.

Working across a range of technologies and product domains, you will play a key role in modernising legacy platforms, solving complex technical challenges, and building cloud-native solutions that support our growing customer base.

Technical Leadership & Delivery

• Provide hands-on technical leadership across software development teams.

• Lead the design, development, and delivery of scalable, secure, and high-performing software solutions.

• Drive architectural decisions and ensure alignment with engineering best practices and business objectives.

• Contribute to estimation, planning, and technical decision-making for new initiatives and product enhancements.

• Work closely with cross-functional teams to support successful product releases and operational excellence.

• Ensure teams understand priorities, milestones, and delivery commitments.

Engineering Excellence

• Remain actively involved in software development, code reviews, troubleshooting, and resolving complex technical issues.

• Champion modern engineering practices, including CI/CD, DevOps, automation, testing, and observability.

• Promote high standards of code quality, maintainability, security, and performance.

• Drive continuous improvement initiatives across development processes, tooling, and ways of working.

• Support the evolution and modernisation of existing platforms and systems.

People Leadership & Mentoring

• Coach, mentor, and develop engineers at all levels, creating a culture of learning and technical excellence.

• Provide line management support where applicable, including performance management, career development, and objective setting.

• Foster collaboration, knowledge sharing, and effective communication across teams.

• Help build high-performing engineering teams by promoting engagement, accountability, and continuous growth.

• Significant experience in software engineering, including leadership of complex technical initiatives and distributed teams.

• Strong expertise within the Microsoft technology ecosystem, including C#, .NET, SQL Server, Azure, and related technologies.

• Experience designing and delivering scalable, cloud-native applications and services.

• Strong understanding of microservices, distributed systems, and modern software architecture principles.

• Ability to write, review, and guide the development of high-quality, well-tested, production-grade code.

• Experience working across multiple programming languages and technology stacks, demonstrating adaptability and a broad technical perspective.

• Deep understanding of software engineering best practices, development lifecycles, and agile delivery methodologies.

• Excellent problem-solving, communication, and stakeholder management skills.

• Cloud platform certifications (Azure, AWS, or GCP).

• Experience with observability, monitoring, and performance optimisation practices.

• Experience modernising legacy applications and driving large-scale technical transformations.

• Technical Leadership & Architecture

• Software Engineering Excellence

• Coaching & Mentorship

• Collaboration & Stakeholder Management

• Ownership & Accountability

• Strategic Decision Making

• Problem Solving & Innovation

• Continuous Improvement Mindset

• Impact: Your work will influence millions globally.

• Growth: Continuous learning and career development opportunities.

• Belonging: A culture that celebrates diversity and empowers every individual.
  

Click Apply - we’re excited to learn about your unique perspective and experience. If you need adjustments during the process, let us know. We’re committed to making this opportunity accessible to everyone.

Our process is designed to be fair, transparent and straightforward. Stages vary depending on the role — more senior positions may involve additional steps, and some areas include role-specific assessments such as a technical test or case study — but typically you can expect:

1. Application review — we assess your experience and potential

2. Initial call — a short conversation to learn about you and share more about the role

3. Skills assessment — tailored to the position, e.g. case study, coding challenge or portfolio review

4. Final interview — meet the team and explore how you'll make an IMPACT at IRIS

We'll always walk you through the specific stages at the start of the process so you can prepare with confidence.

If you need any adjustments or accommodations during the process, let us know, we’re committed to making this experience accessible for everyone.