Backend Software Engineer.Net Java Low Latency

Client Server; Greater London; On-site; GBP 77,000 - 104,000; Full time

Benefits offered by this job

Salary up to £90k

25 days holiday

Pension

Life Assurance

Income protection

Private Medical

Dental care

Gym subsidy

Cycle to work

Stock options

Family leave

Job summary

Client Server is seeking a Backend Software Engineer to help build a high-throughput, low-latency Market Data platform in London. You will work across the full development lifecycle, focusing on C#/.NET and Java, within an Agile team that collaborates with DevOps and Product Management.

The role emphasizes API development, SQL proficiency, and cloud-based deployments on AWS. You will mentor peers and explore new technologies, including Apache Flink, to sustain scalability.

Qualifications

• Strong C#/.NET skills with SOLID, DRY and KISS principles.
• Experience building APIs for high throughput, low latency systems.
• Proficient in SQL, AWS, Terraform and CI/CD practices; familiar with Java.

Responsibilities

• Collaborate with DevOps and Product Management within an Agile team on a Greenfield Market Data platform.
• Contribute to technical design discussions and participate in the full development lifecycle.
• Apply the .NET stack expertise and evaluate new technologies for the platform.
• Mentor junior developers and share best practices across the team.

Skills

C#/.NET

Java

Low latency

API development

SQL

AWS

CI/CD

Terraform

Design patterns

Mentoring

Tools

Apache Flink

Job description

Backend Software Engineer.Net Java Low Latency Client Server London, England

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

Full-time