Principal Software Engineer (C#, Azure, Event Driven)

Armymkt; St Albans; Hybrid; GBP 90,000; Full time

Job summary

A leading technology company in St Albans is seeking a Principal Software Engineer to lead a major digital transformation project. This role involves designing scalable distributed systems, guiding technical decisions, and mentoring engineers. Candidates must have strong experience with event-driven architectures and distributed systems. The position offers a competitive salary of £90,000 plus bonuses and shares, with a hybrid work model.

Qualifications

• Proven experience building and running distributed systems at scale.
• Deep fluency in modern programming languages and frameworks.
• Experience delivering secure, high-availability software into production.

Responsibilities

• Design and build scalable, distributed systems that support critical environments.
• Lead technical decision-making and resolve engineering challenges across domains.
• Own the delivery of complex features, ensuring performance, resilience, and maintainability.

Skills

Distributed systems design

C#

Azure

Event-Driven Architecture

Mentorship

Job description

Principal Software Engineer (C#, Azure, Event Driven)

Join to apply for the Principal Software Engineer (C#, Azure, Event Driven) role at Army Marketing

£90,000 + Bonus + Shares | St Albans (Hybrid)

Method is partnering with a technology company that's about to launch a major digital transformation and rebuild their architecture from the ground up. The company has been in business for nearly 30 years, and after a very successful period, they have acquired several competitors. After a period of consolidation, they are now looking to unify all their systems into a single source of truth.

They are also looking to scale massively over the next 5 years as they enter new markets, and as a result, are looking for a Principal Engineer to help design, build and guide to achieve this. As the Principal Software Engineer, you will be a hands‑on technical authority, assisting with architecture, setting development standards and best practices, and be the technical SME on what will be a massively event‑driven platform.

The Principal Software Engineer that joins this project will be at the very beginning of this transformation. Helping the company decouple an already large monolith into an event‑driven platform that will handle several million events per day, before scaling up to 100+ million events per day. You'll work at the top of the engineering track, designing and delivering high‑performance, distributed systems while guiding others through implementation and problem‑solving. This is a deep technical role, ideal for someone who thrives on code, architecture, and tangible impact.

What You’ll Do

• Design and build scalable, distributed systems that support critical environments.
• Lead technical decision‑making and resolve engineering challenges across domains.
• Own the delivery of complex features, ensuring performance, resilience, and maintainability.
• Collaborate with Engineering Leads, Architects, and Product to translate roadmap goals into reality.
• Contribute to a 5‑year architectural refresh, evolving systems to event‑driven microservices.
• Mentor engineers through design reviews, pairing, and best‑practice development.
• Maintain and improve CI/CD pipelines, test automation, and production reliability.

What You’ll Bring

• Proven experience building and running distributed systems at scale.
• Deep fluency in modern programming languages and frameworks.
• Experience delivering secure, high‑availability software into production.
• Strong understanding of architecture, design patterns, and microservice principles.
• Ability to balance hands‑on coding with architectural oversight and mentorship.
• Curiosity to explore new tools, paradigms, and emerging technologies.

Why Join

You’ll be at the forefront of a long‑term platform rebuild, working with modern architectures, cloud‑native tooling, and a leadership team that genuinely invests in engineering excellence. The company is also offering a lucrative package that will have a considerable positive impact to the person who secures this role.

To Apply

Please send CV directly or contact Brent Chambers on 0117 457 8574.

RSG Plc is acting as an Employment Agency in relation to this vacancy.