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.
IRIS provides integrated software across accountancy, finance, HR, payroll, education and business operations. Our approved company material confirms that IRIS supports more than 100,000 customers across 135 countries.
As an L3 Software Engineer, you'll help develop the applications and data platforms behind that technology. You'll take ownership of small to medium-sized features through their complete lifecycle, delivering scalable, maintainable solutions and contributing to technical decisions within your feature scope.
It's a hands-on role with meaningful ownership, backed by experienced colleagues when you're tackling broader or more complex engineering challenges.
You'll work within an Agile, cross-functional environment, collaborating with Product Owners, QA, Design and fellow engineers to refine user stories and turn requirements into robust production software.
Your contribution won't stop at writing code. You'll take part in code reviews, pair programming and knowledge sharing, mentor junior colleagues and contribute to technical and architectural discussions.
You'll:
Deliver full-stack features from analysis through to production.
Build backend services using C#, .NET Core, ASP.NET Core Web APIs and REST.
Develop with modern frontend frameworks such as Angular, React or Vue.js, alongside TypeScript.
Design and work with SQL Server and potentially CosmosDB or DynamoDB.
Build and maintain microservices and robust APIs.
Deploy containerised applications with Docker and Kubernetes using Azure or AWS.
Extend CI/CD pipelines using Azure DevOps Pipelines or GitHub Actions.
Apply automated testing and TDD/BDD practices, plus security and quality controls.
Use observability tools such as DataDog, Application Insights or Amazon CloudWatch.
Use AI-assisted engineering tools critically and responsibly across design, development, testing and debugging.
Mentor junior engineers and contribute to effective Agile delivery.
You'll bring 2–4 years of professional software development experience and a track record of delivering software using Agile methodologies.
You'll need strong .NET/C# backend development skills, SQL Server experience and knowledge of scalable web applications and cloud deployments. We're also looking for experience or working knowledge across CI/CD, containerisation, Infrastructure as Code, automated testing, observability and clean architecture/SOLID principles.
Frontend experience with Angular, React or Vue.js is valuable, although a backend specialist with working frontend knowledge can also fit the role.
You'll be comfortable owning routine work independently, working with guidance on more complex features and providing technical support or mentoring to junior colleagues.
Experience with regulated or complex domains, event-driven architectures, GraphQL, real-time technologies, NoSQL databases or modern UI architecture patterns would be advantageous rather than essential.
This role offers the combination of hands-on engineering ownership and continued development. You'll broaden your skills across full-stack development, cloud infrastructure, modern DevOps and AI-assisted engineering while developing leadership skills through mentoring and architectural contribution.
You'll be contributing to IRIS's broader cloud transformation with technology used across accountancy, payroll, HR and education, while being supported by an experienced engineering community.
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:
Application review — we assess your experience and potential
Initial call — a short conversation to learn about you and share more about the role
Skills assessment — tailored to the position, e.g. case study, coding challenge or portfolio review
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.
Develop and support full-stack features for a cloud-native retail platform, building.NET microservices, Angular interfaces, and API integrations while maintaining Azure services and resolving production issues.
Improve product security and privacy by writing software, auditing features for weaknesses, and guiding engineering decisions with threat modeling and practical security analysis.
Build and harden Mecatl, a cloud-native agent harness, delivering features across its engine, Kubernetes runtime, client SDKs, and security layers to make production AI agents reliable and safe.
Build and maintain high-quality software for sports trading and pricing, partnering with quantitative analysts to implement price models and improve platforms across the software delivery lifecycle.
Design, build, and operate production systems that evaluate AI agent behavior, detect risk, and support safe actions, translating alignment research into reliable capabilities across agent experiences.
