Senior Backend Engineer (Java/.Net & Microservices) NEW

City, London
ARM
Senior Backend Engineer (.NET / Java Microservices) Contract: Inside IR35 Duration: 6 Months+ Hybrid – 2 days per week on site in London

We’re seeking a Senior Backend Engineer to design, build and enhance scalable backend services and APIs within a complex enterprise environment. You’ll play a key role in delivering modern microservices while contributing to technical design and engineering best practice.

Key Responsibilities

• Design and develop backend services using C#/.NET and Java (Spring Boot).
• Build and support REST APIs and microservices.
• Contribute to architecture, technical design and system integration.
• Troubleshoot, optimise and support production systems.
• Collaborate with stakeholders and mentor other engineers.

Essential Skills

• Strong commercial experience with C#/.NET and Java (Spring Boot).
• Proven delivery of microservices and REST APIs.
• Experience with distributed systems and enterprise integration.
• Strong SQL experience (SQL Server and/or Oracle).

We’re Looking For

• Engineering Ownership – Takes responsibility for delivery end-to-end, including debugging, optimisation and resolving production issues.
• Microservices & Distributed Systems – Strong understanding of scalable, distributed architectures and the challenges around reliability and performance.
• Event-Driven Thinking – Knowledge of event-driven architectures, decoupled systems and real-time data flows.
• Architecture & Design – Applies sound engineering principles and contributes to solution design and technical decisions.
• Seniority & Influence – Operates at Senior Engineer or Tech Lead level, mentors others, challenges requirements and engages confidently with stakeholders.
• Enterprise Experience – Experience delivering within complex enterprise environments. Financial services experience is advantageous but not essential.

This is an excellent opportunity for a senior engineer who enjoys solving complex technical challenges and influencing both architecture and delivery within a collaborative engineering team.

Disclaimer:

This vacancy is being advertised by either Advanced Resource Managers Limited, Advanced Resource Managers IT Limited or Advanced Resource Managers Engineering Limited (“ARM”). ARM is a specialist talent acquisition and management consultancy. We provide technical contingency recruitment and a portfolio of more complex resource solutions. Our specialist recruitment divisions cover the entire technical arena, including some of the most economically and strategically important industries in the UK and the world today. We will never send your CV without your permission. Where the role is marked as Outside IR35 in the advertisement this is subject to receipt of a final Status Determination Statement from the end Client and may be subject to change.