Backend Software Engineer .Net Java Low Latency

Client Server; Greater London; Hybrid; GBP 80,000 - 90,000; Full time

Benefits offered by this job

25 days holiday

Pension

Life Assurance

Income protection

Private Medical and Dental care

Gym subsidy and wellness apps

Cycle to work scheme

Stock options

Family leave and sabbaticals

Personalised training budget

Job summary

Client Server is seeking a Backend Software Engineer to join a London-based team building a high‑throughput, low‑latency Market Data platform. You will work on C#/.NET and Java stacks, APIs, and cloud deployments in an Agile setting, delivering scalable backend services.

You will collaborate across DevOps and Product teams, design for performance, and mentor junior developers while contributing to architectural discussions. London office with hybrid work options.

Qualifications

• Strong C#/.NET and Java experience with low-latency systems.
• Experience building and consuming APIs, with solid SQL skills.
• Familiar with CI/CD, IaC (Terraform) and AWS cloud.

Responsibilities

• Collaborate in an Agile team to build a high-throughput, low-latency Market Data platform.
• Contribute to technical design and hands-on development across the full software lifecycle.
• Mentor junior developers and participate in code reviews and architectural discussions.

Skills

C# / .NET

Java

APIs

SQL

CI/CD

Design Patterns

AWS

Mentoring

Agile

Tools

Apache Flink

Terraform

Job description

Backend Software Engineer .Net Java Low Latency (PR/100814) London, England

Salary: GBP80000 - GBP90000 per annum + bonus + benefits

Backend Software Engineer / Developer (C# .Net Java Low Latency) London to £90k

Are you a technologist who enjoys contributing to technical discussions and using the best tool for the job?

You could be progressing your career at a global, financial Market Data provider whilst enjoying a range of perks and benefits.

What’s in it for you:

• Salary to £90k + bonus
• 25 days holiday
• Pension, Life Assurance and Income protection
• Private Medical and Dental care
• Gym subsidy and wellness apps
• Cycle to work scheme
• Ability to buy stock options
• Family leave and sabbaticals
• Continuous training and career development including personalised budget

Your role:

As a Backend Software Engineer you will collaborate with DevOps and Product Management within an Agile team environment working on a Greenfield Market Data platform. The platform has been built with C# deploying to AWS and requires high scalability and low latency – they currently handle 40 billion messages per day.

You’ll work across the full development lifecycle, from requirements and design through to production, providing subject matter expertise on the .Net stack and contributing to technical design discussions. You’ll use a range of technology including Apache Flink with Java for large scale data processing and will be able to assess and recommend new and emerging technologies, using the best tool for the job.

Location / WFH:

You’ll join colleagues in the City office four days a week with flexibility to work from home once a week.

About you:

• You have strong C# .Net skills and a good understanding of design patterns such as SOLID, DRY and KISS Design Principles
• You’ve worked on systems that require high throughput, low latency and scalability and understand the challenges involved (finance experience not required)
• You have strong experience of building APIs
• You have SQL experience
• You have a good understanding of CI/CD and Infrastructure as Code (Terraform)
• You have cloud experience with AWS
• You’re familiar with other languages such as Java and are open to learn new things
• You’re comfortable with using agentic AI and tools to help improve productivity
• You’re collaborative with great communication skills, happy to mentor more junior developers

Yes, I am currently eligible to work (work permit/visa/citizenship) in the country to which I am applying. No, I am not currently eligible to work (work permit/visa/citizenship) in the country to which I am applying.