Principal Software Engineer in Belfast

We’re looking for experienced Principal Software Engineers who enjoy solving complex technical problems, shaping architecture, and leading the design and delivery of high-quality software in production environments. This role is suited to someone who combines strong hands-on engineering capability with technical leadership. You’ll work across backend systems, cloud infrastructure, and distributed architectures, helping teams make sound technical decisions while staying close enough to the code to guide delivery in a practical way. It’s a strong fit for someone who takes ownership, sets a high engineering bar, and enjoys influencing how systems are designed, built, and evolved over time.

What You’ll Be Doing

• Design and deliver robust, scalable software systems using technologies like Java, C#/.Net, TypeScript or Python.
• Lead architectural decisions across services, platforms, and cloud-native systems.
• Build and guide the development of backend services, APIs, and event-driven systems.
• Work across AWS, Azure, or GCP to design reliable and secure cloud-based solutions.
• Apply agentic ways of working, using AI tools to support design, development, testing, and delivery.
• Help teams adopt effective patterns for integrating AI into engineering workflows and systems.
• Provide technical leadership to engineering teams, helping shape direction and unblock delivery.
• Contribute hands-on where needed, particularly in complex or high-impact areas of implementation.
• Drive improvements in engineering practices, system design, deployment processes, and operational maturity.
• Support teams with technical mentoring, design reviews, and problem-solving across the software lifecycle.
• Collaborate with platform, product, and delivery teams to ensure systems are scalable, maintainable, and production-ready.
• Help define technical standards and influence how engineering is done across projects and teams.

Required

• Strong experience designing and delivering production-grade software systems using technologies such as Java, C#/.Net, TypeScript or Python.
• Significant experience working with cloud platforms such as AWS, Azure, or GCP.
• Strong background in system design, architecture, and building scalable distributed systems.
• Experience designing and building APIs, backend platforms, and event-driven services.
• Proven ability to make sound technical decisions and guide teams through complex engineering challenges.
• Comfortable working across the full software delivery lifecycle, from design through to deployment and operation.
• Strong grasp of software engineering fundamentals, patterns, and best practices.
• Experience adopting agentic ways of working, using AI tools to enhance engineering productivity and delivery.
• Ability to balance hands-on delivery with technical leadership and strategic thinking.
• Strong communication skills and the ability to work effectively with engineers, stakeholders, and cross-functional teams.

Nice to Have

• Experience with frontend technologies such as React, Angular, or Vue.
• Familiarity with infrastructure-as-code tools such as Terraform or CloudFormation.
• Experience with containerisation and orchestration using Docker and Kubernetes.
• Exposure to CI/CD tooling such as GitHub Actions, GitLab CI, or similar.
• Experience building or integrating AI-driven features or systems.
• Experience working in consulting, product, or cross-functional delivery environments.
• Interest in improving engineering standards, mentoring others, and shaping technical culture.
• Experience working across multiple teams or projects in a senior technical leadership capacity.

Why Join Instil?

• Recognition That Matters: A discretionary annual performance bonus that rewards your impact and contribution to our success.
• Flexibility Built In: Flexible working arrangements and summer hours, because life isn’t 9 to 5, and balance matters.
• Financial Security: A highly competitive pension scheme with generous employer contributions, private healthcare, and life assurance for peace of mind.
• Health & Wellbeing: Employee Assistance Programme, mental health support, cycle-to-work scheme, and regular social events to keep our culture vibrant.
• Time to Recharge: 35 days holiday, enhanced maternity pay, and family-first policies so you can focus on what matters most.
• Learning Never Stops: From courses to certifications, we’ll invest in your development so you can keep growing and shaping what’s next.
• Community & Culture: Opportunities to volunteer, give back, and be part of initiatives that make Instil a truly inclusive and connected workplace.

Instil has been delivering world-class software engineering and technology solutions for over 20 years, trusted by global brands to solve complex challenges and drive innovation. From modernising legacy systems to building cutting-edge applications, we help our clients navigate an ever-changing digital landscape with confidence and agility.

We’re proud to be an award-winning employer, reflecting how our people are at the heart of everything we do: Recognised as a Great Place to Work® for three consecutive years, and in 2024 ranked in the Top 20 Best Workplaces in the UK for medium-sized companies. Winner of Company of the Year at the Digital DNA Awards 2022, celebrating excellence in Northern Ireland’s tech sector. Driven by a love for technology and a commitment to excellence, we bring together people who want to make a difference. We’ll support your journey, because your success is part of ours.