Principal Software Engineer

Interact provides enterprise-grade intranet software that connects over three million employees to leading global names like Levi's, Domino’s, Teva Pharmaceuticals, and Technicolor.

Our team of customer-focused problem solvers are passionate about helping organizations to communicate better. We do this together by constantly working to improve every service and product we offer. With offices in Manchester, New York, Dubai, Tulsa, and Warsaw, we operate across North America, EMEA, and Australia.

Click on any of our vacancies and you’ll see one thing in common – they all begin with this message. Why? Because at Interact we treat everyone with the same respect and honesty. Whether you’re a developer fresh out of college or a seasoned salesperson, we live the motto that we uphold for our customers: our people are our most valuable assets.

We are looking for a Principal Software Engineer, who will be a hands‑on engineer responsible for fast development of strategic functionality, AI integrations in the core product, shaping the architecture, driving engineering excellence, and delivering complex features across our platform used by millions of users globally.

A core part of the role is end‑to‑end execution of AI integrations into our existing ecosystem, including architecture, implementation, governance, and enablement across squads.

You will combine deep technical capability with strong leadership influence—mentoring engineers, guiding technical strategy, and personally contributing high‑quality code across our stack (C#, ASP.NET, ReactJS, Node.js, SQL Server, AWS).

• 10+ years of professional engineering experience, including designing and delivering large-scale, distributed systems.
• Proven track record of hands‑on development across back‑end (C#, ASP.NET) and front‑end (ReactJS) environments.
• Extensive experience integrating AI/LLM technologies into production environments.
• Strong competence with SQL Server, T‑SQL, performance tuning, caching (Redis), Elastic Search/Open Search, and distributed systems patterns.
• Experience operating in Agile/Scrum and collaborating closely with Product, Delivery, QA, and Dev Ops.
• Strong Git and CI/CD experience (Bitbucket, Team City, Octopus Deploy).
• Real‑world experience designing secure, scalable, resilient systems on AWS.
• Expert understanding of OOP, SOLID principles, design patterns, data structures, and algorithms.
• Deep knowledge of asynchronous processing, concurrency, distributed architectures, and high‑volume transactional systems.
• Working knowledge of Docker, containerised workloads, and cloud‑native best practices.
• Understanding of modern AI integration patterns: embeddings, vectors, RAG, prompt engineering, evaluation techniques, model safety.
• Strong familiarity with Atlassian tools (Jira, Confluence).
• Hands‑on technical leader with a bias for action and ownership.
• Excellent communicator who can simplify complex systems for technical and non‑technical audiences.
• Pragmatic, user‑centric problem solver with strong attention to detail.
• Curious, innovative, and proactive in driving the organisation forward.
• Collaborative, empathetic team player who uplifts others.
• Strategic thinker who can balance immediate delivery with long‑term architecture needs.

• Design, build, and ship high‑quality, production‑grade software using C#, ASP.NET, ReactJS, Node.js, SQL Server, and AWS services.
• Serve as a hands‑on architect/engineer— writing foundational code, delivering end to end features, validating technical approaches through prototypes and spikes, and leading design discussions.
• Maintain deep familiarity with our codebase and actively contribute to critical, high‑impact features and refactoring initiatives.
• Define and uphold engineering standards across squads, including SOLID, design patterns, secure coding, and observability principles.
• Evaluate technical trade‑offs, performance implications, and long‑term maintainability to steer architectural direction.

• Lead and implement AI‑powered features across Interact’s ecosystem, to fuel value creation (eg. intelligent search,…