Principal Engineer / Staff .NET Developer
At a Glance
• Principal / Staff-level role with real ownership over technical direction and platform strategy
• Deep .NET / C# stack... modern cloud-native architecture across Azure or AWS
• Hybrid working from a Belfast city centre office
• Salary range available on application, reflecting genuine seniority
• Lead a full-scale platform modernisation programme with long-term, visible impact
About the Company
Our client is a technology organisation on a genuine platform transformation journey, moving away from complex legacy systems toward a modern, cloud-native architecture. Operating at significant scale, they run multiple engineering teams across Belfast and international sites and are investing heavily in raising their engineering capability, both technically and culturally. This is a business where architecture decisions matter and where the right engineering leader will leave a lasting mark on a mission-critical platform.
The Role
This is a senior leadership position combining deep architectural ownership with people leadership. Reporting directly into the CTO or Head of Engineering, you will define the long-term technical direction, guide multiple teams through a significant legacy modernisation programme, and work closely with senior stakeholders to ensure every architecture decision supports both product ambition and future scale. This is not an advisory seat... you will own the outcomes. The right person thrives with genuine autonomy, is energised by leading change rather than recommending it, and has the seniority to earn trust quickly at every level of the organisation.
Key Responsibilities
Architecture and platform modernisation
• Define and own the target architecture, leading the transition from legacy systems to modern, cloud-native platforms
• Drive the decomposition of monolithic systems into modular services, APIs, and event-driven components
• Introduce modern engineering practices and tooling to improve delivery quality, reliability, and developer experience
• Collaborate with front-end and back-end leaders to ensure scalability, performance, and consistency across the platform
Technical leadership
• Provide architectural oversight across multiple teams and applications
• Lead platform evolution initiatives including cloud migration, containerisation, and CI/CD automation
• Champion software craftsmanship, testing strategies, and design patterns across the engineering organisation
• Identify and resolve complex technical and performance issues across distributed systems
Engineering management and culture
• Lead and mentor engineering managers and senior engineers across Belfast and international sites
• Establish and run architecture governance through review boards and technical working groups
• Support team growth, performance, and long-term capability development
• Help scale engineering culture and processes as the organisation continues to grow
Delivery and stakeholder engagement
• Own the delivery of strategic technical initiatives from design through to implementation
• Partner with product, infrastructure, and senior leadership to define architectural roadmaps
• Communicate architectural decisions clearly to both technical and non-technical audiences
• Develop proofs of concept and technical spikes to validate architectural direction
What You’ll Need
Essential:
• 10+ years’ professional software engineering experience
• Strong .NET / C# background across legacy and modern frameworks
• Proven track record leading large-scale platform modernisation programmes
• Experience operating at Principal Engineer, Architect, Engineering Manager, or equivalent level
• Deep understanding of distributed systems, APIs, and event-driven architectures
• Hands-on experience with Azure or AWS and container platforms such as Kubernetes
• Experience leading and mentoring multiple engineering teams
• Ability to communicate complex technical concepts clearly at senior leadership level
• Right to work in the UK
Desirable / Nice to Have:
• Experience with architectural experimentation and prototyping
• Background working across Belfast-based and international engineering teams
• Familiarity with SQL Server, PostgreSQL, and performance optimisation at scale
Why Apply?
• Lead a major platform transformation with long-term, visible impact on a mission-critical system
• Genuine ownership over technical direction... not a seat at the table, the head of it
• Hybrid working with a Belfast city centre office and real flexibility built in
• Clear progression paths across Principal Engineer, Head of Engineering, and Enterprise Architecture
• Supportive engineering culture built on quality, trust, and delivery
• Work alongside experienced engineers and leaders who care about doing things properly
Next Steps
Get in touch with Ryan Quinn at Ocho People for a confidential conversation about this role. Connect on LinkedIn or reach out directly at ryan@ochopeople.com.
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