Senior Java Software Engineer

OneAPPS Consulting; Burgess Hill; Hybrid; GBP 90,000 - 130,000; Full time

Job summary

OneAPPS Consulting in Burgess Hill, West Sussex, UK, is seeking an experienced Senior Java Backend Engineer / Technology Lead to join a major financial services technology programme.

You will design, develop and maintain scalable backend services and RESTful APIs using Java 17+, Spring Boot and Microservices.

This role involves technical leadership, code reviews, CI/CD, and improving observability; Kotlin upskilling is available.

Qualifications

• Proven experience designing and building backend services with Java 17+ and Spring Boot.
• Strong knowledge of Microservices, REST APIs and scalable architectures.
• Experience leading engineering teams in Agile environments; Banking/Payments domain preferred.

Responsibilities

• Design, develop and maintain scalable backend services and RESTful APIs using Java 17+, Spring Boot and Microservices.
• Build and enhance Backend for Frontend (BFF) services supporting enterprise mobile applications.
• Contribute to microservices architecture, API design, performance optimisation and system reliability.
• Provide technical leadership, code reviews and engineering best practices.
• Develop automated tests and maintain high standards of code quality.
• Implement and support CI/CD pipelines for reliable production deployments.
• Collaborate with engineering, product, architecture and QA teams in an Agile environment.
• Support monitoring, troubleshooting and production observability.

Skills

Java 17+

Spring Boot

Microservices

RESTful APIs

Backend for Frontend

CI/CD

Observability

Distributed systems

Leadership

Agile/Scrum

Tools

Maven

Gradle

GitHub Actions

CircleCI

ELK

Dynatrace

Sentry

Job description

OneAPPS Consulting (www.oneapps.com) is a Technology consulting firm based out of London and offices across Europe. We are working on various projects involving diverse, multicultural teams with clients across the Europe. We are an invaluable partner and our teams have collaborated to support the growth of our clients. With more than 7 locations worldwide we help our clients to deliver their projects smoothly. We look forward to getting to know you and working with you.

Location: Burgess Hill, West Sussex, UK

Work Mode: Hybrid - 3 days onsite per week

Industry: Financial Services / Payments Technology

OneAPPS is looking for an experienced Senior Java Backend Engineer / Technology Lead to join a major financial services technology programme in Burgess Hill.

You will be part of a Mobile Engineering team developing highly scalable, secure and resilient backend services supporting mobile applications used by millions of cardholders globally.

We are particularly interested in senior engineers with strong expertise in Java, Spring Boot and Microservices. Prior Kotlin experience is NOT mandatory, as suitable candidates will have the opportunity to upskill in Kotlin.

Key Responsibilities

• Design, develop and maintain scalable backend services and RESTful APIs using Java 17+, Spring Boot and Microservices.
• Build and enhance Backend for Frontend (BFF) services supporting enterprise mobile applications.
• Contribute to microservices architecture, API design, performance optimisation and system reliability.
• Provide technical leadership, code reviews and engineering best practices.
• Develop automated tests and maintain high standards of code quality.
• Implement and support CI/CD pipelines for reliable production deployments.
• Collaborate with engineering, product, architecture and QA teams in an Agile environment.
• Support monitoring, troubleshooting and production observability.
• Strong hands-on expertise in Java 17+, Spring Boot and Microservices architecture.
• Experience developing REST APIs and enterprise backend applications.
• Strong understanding of distributed systems, application performance and scalability.
• Experience with Maven or Gradle.
• Knowledge of CI/CD pipelines, preferably GitHub Actions or CircleCI.
• Experience working in Agile/Scrum engineering teams.
• Ability to troubleshoot complex backend application issues.
• Backend for Frontend (BFF) architecture.
• Observability tools such as ELK, Dynatrace or Sentry.
• Previous experience in Banking, Payments or Financial Services.
• Experience mentoring developers or technically leading engineering teams.

Why Consider This Opportunity?

• Work on high-volume, globally used financial technology platforms.
• Modern engineering environment using Java, Spring Boot, Microservices and Kotlin.
• Opportunity to progress into Kotlin-based backend development.
• Potential contract extension or permanent employment based on performance.