Principal Backend Engineer: Java/Spring Boot, AWS & Kafka

Client Server Limited; Greater London; Hybrid; GBP 108,000 - 132,000; Full time

Benefits offered by this job

Pension

Life Assurance

Income Protection

Private medical care

Travel Insurance

Charitable giving

Gym membership

Flexible holidays

Job summary

Client Server Limited is seeking a Principal Backend Engineer to own complex Java backend projects, leading client engagements and delivering high-impact transformations. You will design, build and optimise scalable Spring Boot microservices, migrate legacy systems to AWS, and champion modern CI/CD and DevOps practices.

You will collaborate with a talented team focused on engineering excellence and client outcomes, blending hands-on development with strategic leadership in a fast-paced financial

Qualifications

• Experience in Java software engineering, especially in financial services or Fintech environments.
• Strong Java development skills including multi-threading and concurrency.
• Experience with Spring Boot and microservices architectures.
• Solid knowledge of Kafka and REST APIs.
• Hands-on AWS experience and cloud deployment practices.
• Familiarity with DevOps, CI/CD pipelines and modern software delivery.
• Strong fundamentals in OOP, data structures, and design patterns.

Responsibilities

• Lead technical projects and client engagements from design to delivery.
• Develop scalable Java applications using Spring Boot and microservices.
• Modernise legacy systems and migrate them to AWS.
• Design and implement REST APIs and distributed systems.
• Introduce and improve CI/CD and DevOps practices.
• Provide technical leadership and guidance to clients and engineering teams.

Skills

Java

Spring Boot

Kafka

AWS

REST APIs

Microservices

DevOps

CI/CD

Multi-threading

OOP

Data Structures

Design Patterns

Job description

Client Server Limited is seeking a Principal Backend Engineer to own complex Java backend projects, leading client engagements and delivering high-impact transformations. You will design, build and optimise scalable Spring Boot microservices, migrate legacy systems to AWS, and champion modern CI/CD and DevOps practices.

You will collaborate with a talented team focused on engineering excellence and client outcomes, blending hands-on development with strategic leadership in a fast-paced financial