Principal Engineer - Full Stack

About this role

Our Why Datacom works with organisations and communities across Australia and New Zealand to make a difference in people’s lives and help organisations use the power of tech to innovate and grow. About the Role (your why) We know Payroll and have been processing payroll accurately and compliantly for over 50 years. The Principal Full Stack Engineer plays a critical role in shaping the software that powers Datapay – our SaaS Payroll platform used by organisations across the region. This role is about delivering real business outcomes: helping customers run payroll accurately, meet regulatory obligations on time, and scale with confidence as their needs change. As a technical leader you will work hands-on across the full stack – from architecture and technical design through to implementation and customer engagement. You will collaborate closely with Product and Design teams, Tech Leads, and Architects to ensure value flows consistently to customers. You will mentor engineers, set engineering standards, and make architectural decisions that allow teams to move fast without creating risk. While the technology selection below is broad, we will expect expert-level capability in some areas and working knowledge in others – we look forward to discussing that with you at interview. What you’ll do Lead development teams through influence – shaping technical direction, creating clarity, and enabling teams to deliver consistently and with confidence. Architect and champion hexagonal (ports-and-adapters) architecture across the platform – separating core business logic from infrastructure concerns so the domain stays clean, testable, and adaptable as the business evolves. Lead the evolution of an existing monolithic architecture toward a modern, composable platform – incrementally decomposing tightly coupled capabilities into well-defined services, reducing coupling at the right pace, and laying the foundations that allow AI-assisted development to accelerate delivery without compounding technical debt. You will make pragmatic strangler-fig decisions, knowing when to extract, when to refactor in place, and how to keep the business running throughout. Define and govern integration contracts between services – designing stable APIs, lightweight messaging patterns, and clear service boundaries that allow teams to build and deploy independently without introducing hidden coupling. Solve real distributed systems challenges – fault tolerance, eventual consistency, idempotency, and cross-service failure recovery – grounded in the specific demands of payroll accuracy and compliance. Champion system-level thinking in an AI-accelerated Software Development Lifecycle (A-SDLC) where code output is significantly increased. Ensure architecture fitness tests, contract tests, and deployment safeguards are in place so services can be deployed to production independently and with confidence. Collaborate with Product and Design teams to translate business requirements into well-scoped engineering solutions – balancing short-term delivery with long-term platform health. Make informed tech stack choices and capture architectural knowledge continuously, building shared understanding across the team. Mentor developers in both technical and delivery skills, raising the capability of the team around you. Lead communication and collaboration across Development, Design, and Product teams to ensure alignment and create successful outcomes for customers. What you’ll bring 10+ years in Software Development, with at least 4 years in a large IT organisation in a senior or principal-level engineering role. Expert-level proficiency in C#/.NET and .NET Core – you can lead, design, and mentor in the primary language of our platform. Proficiency in Python – whether for backend services, scripting, data pipelines, or tooling, Python sits comfortably in your toolkit alongside C#. Proven experience designing systems using hexagonal or clean architecture principles – you understand how to protect the domain from infrastructure concerns and why it matters at scale. Hands-on experience evolving or decomposing monolithic systems – you have navigated the real challenges of incremental migration, maintaining live systems during transition, and making pragmatic trade-offs between ideal architecture and delivery reality. Strong distributed systems experience: you have dealt with the real challenges of service-to-service communication, fault tolerance, eventual consistency, and cross-service debugging – not just studied the theory. Experience with message brokers and async communication patterns in microservices environments (e.g. Azure Service Bus, RabbitMQ, or similar). Knowledge of web front-end technologies including HTML, JavaScript, TypeScript, CSS, and React (or a comparable framework). Experience with spec-first development using OpenAPI/Swagger, and a strong testing mindset spanning unit, regression, E2E, contract testing (e.g. Pact), and architecture fitness tests. Experience leveraging AI-assisted development workflows to accelerate delivery, with a focus on maintaining architectural integrity, code quality, and system coherence as development velocity increases. Experience with cloud platforms (Azure preferred), containerisation, CI/CD pipelines, and infrastructure-as-code – you understand how architecture decisions affect deployability and operability. Effective presentation and communication skills – you can convey technical decisions clearly to both engineering teams and non-technical stakeholders. Why join us here at Datacom? Datacom is one of Australia and New Zealand’s largest suppliers of Information Technology professional services. We have managed to maintain a dynamic, agile, small business feel that is often diluted in larger organisations of our size. It’s our people that give Datacom its unique culture and energy that you can feel from the moment you meet with us. We care about our people and provide a range of perks such