Principal Software Engineer

Instil; Belfast City District; Hybrid; GBP 90,000 - 125,000; Full time

Benefits offered by this job

Flexible hybrid working

Belfast office access

Job summary

Instil is seeking a Principal Software Engineer to design, build, and guide the delivery of scalable software solutions across Java, Python, C#/.NET and TypeScript. You will lead architecture, mentor engineers, and drive AI-enabled development in production environments.

You’ll own technical direction, collaborate with platform teams, design cloud-native apps on AWS/Azure/GCP, and shape standards while delivering production-ready software in a hybrid Belfast-based role.

Qualifications

• Extensive experience building production systems using Java, Python, C#/.NET or TypeScript.
• Experience with cloud platforms AWS, Azure or GCP.
• Strong system design and distributed systems knowledge.
• Experience building/consuming REST and event-driven APIs.
• Ability to make architectural decisions and guide complex projects.
• Experience across the full software delivery lifecycle.
• Strong fundamentals and best practices in software engineering.
• Ownership mindset to drive solutions end-to-end.
• Excellent communication with stakeholders.
• Mentoring engineers and supporting team development.
• Interest in AI-enabled engineering and continuous improvement.

Responsibilities

• Design, build, and guide delivery of software using Java, Python, C#/.NET and TypeScript.
• Develop cloud-native apps across AWS, Azure, GCP.
• Provide technical leadership on complex projects and programmes of work.
• Contribute to system architecture and make key technical decisions.
• Work with distributed systems, APIs, and event-driven architectures.
• Collaborate with platform teams to ensure reliable, scalable deployments.
• Contribute to CI/CD pipelines and improve engineering workflows.
• Leverage AI-assisted development tools and agentic workflows to improve productivity and software quality.
• Identify opportunities to automate engineering tasks through intelligent tooling and AI.
• Mentor engineers and support technical growth across teams.
• Work closely with cross-functional teams to deliver production-ready software.
• Help establish and promote engineering standards, best practices, and ways of working.

Skills

Java

Python

C#/.NET

TypeScript

AWS

Azure

GCP

System design

Distributed systems

REST APIs

Event-driven

Technical leadership

SDLC

Best practices

Ownership

Communication

Mentoring

AI in engineering

Tools

React

Angular

Vue

Terraform

CloudFormation

Docker

Kubernetes

GitHub Actions

GitLab CI

Azure DevOps

Serverless

AI services

LLMs

Agent-based systems

Job description

The Role

We’re looking for experienced Principal Software Engineers who enjoy solving complex technical challenges, building scalable systems, and helping engineering teams deliver high-quality software in production environments.

This role sits at the intersection of software engineering, architecture, and cloud/platform engineering. You’ll be designing, building, and guiding the delivery of modern software solutions using technologies such as Java, Python, C#/.NET and TypeScript, while working closely with engineering teams to ensure solutions are scalable, secure, and maintainable.

It’s a strong fit for someone who enjoys taking ownership of technical direction, mentoring engineers, and helping shape how systems are designed, built, and operated. We're also looking for engineers who embrace modern engineering practices, including AI-assisted development and agentic ways of working, to help teams work more effectively and deliver greater value.

What You’ll Be Doing

• Design, build, and guide the delivery of software solutions using Java, Python, C#/.NET and/or TypeScript
• Develop cloud-native applications across AWS, Azure, or GCP
• Provide technical leadership on complex projects and programmes of work
• Contribute to system architecture and make key technical decisions
• Work with distributed systems, APIs, and event-driven architectures
• Collaborate with platform teams to ensure reliable, scalable deployments
• Contribute to CI/CD pipelines and improve engineering workflows
• Leverage AI-assisted development tools and agentic workflows to improve productivity and software quality
• Identify opportunities to automate engineering tasks through intelligent tooling and AI
• Mentor engineers and support technical growth across teams
• Work closely with cross-functional teams to deliver production-ready software
• Help establish and promote engineering standards, best practices, and ways of working

Required

• Extensive experience building production systems using Java, Python, C#/.NET or TypeScript
• Significant experience working with cloud platforms (AWS preferred, Azure or GCP also considered)
• Strong understanding of system design, distributed systems, and scalable architectures
• Experience building and consuming APIs (REST and event-based systems)
• Experience making architectural decisions and providing technical guidance on complex projects
• Comfortable working across the full software delivery lifecycle (build, deploy, operate)
• Strong understanding of software engineering fundamentals and best practices
• Ability to take ownership and drive technical solutions from concept through to delivery
• Excellent communication and stakeholder engagement skills
• Experience mentoring engineers and supporting team development
• Interest in modern AI-enabled engineering practices and continuous improvement

Nice to Have

• Experience with React, Angular, or Vue
• Experience with infrastructure-as-code tools such as Terraform or CloudFormation
• Exposure to containerisation and orchestration technologies such as Docker and Kubernetes
• Familiarity with CI/CD tooling such as GitHub Actions, GitLab CI, or Azure DevOps
• Experience with serverless architectures
• Experience integrating AI services, LLMs, or agent-based systems into software products
• Experience working across multiple teams, projects, or customer engagements
• Interest in improving engineering standards, tooling, and ways of working through automation and AI-assisted development

Please note: We offer flexible hybrid working, but candidates should be based in Northern Ireland and able to attend our Belfast office when required.

Why Join Instil?

At Instil, we believe great work starts with happy, motivated people. That’s why we’ve built a benefits package that supports your wellbeing, growth, and life outside of work, because when you thrive, so do we.

• 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.

And that’s just the start, drop us a note to find out more.

Company Description

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.