Senior Java Software Engineer

SmartChoice International Limited; Greater London; On-site; Full time

Job summary

A leading technology firm in the United Kingdom is seeking a Senior Backend Developer to support a data platform programme for a global financial services organisation. The successful candidate will design and implement backend services, ensure high levels of automated testing, and integrate with various systems. Mandatory skills include strong experience with Java (17/21), Spring frameworks, and robust testing with JUnit and Mockito. This role does not offer sponsorship and is for a 6-month contract.

Qualifications

• Strong experience building backend services using Java (17/21) and Spring/Core frameworks.
• Deep knowledge of JDBC, SQL parsing/validation, and query optimisation.
• Solid understanding of SQL query planning and execution paths.
• Robust testing skills with JUnit5, Mockito, and Cucumber.

Responsibilities

• Design and implement core functionality within Data Fabric backend services.
• Develop and enhance rule definitions used for policy enforcement.
• Integrate with additional backend systems and maintain API documentation.
• Ensure high levels of automated test coverage.

Skills

Building backend services using Java (17/21)

Spring/Core frameworks

JDBC, SQL parsing/validation, and query optimisation

SQL query planning and execution paths

Data structures and algorithms

JUnit5, Mockito, Cucumber

Clean architecture principles and dependency injection

Docker, Jenkins, Maven

Job description

SmartChoice are supporting a data platform programme for a global financial services organisation and require a number of senior backend (Java) developers to join on a 6 month contract.

In this role you will be responsible for:

• Design and implement core functionality within Data Fabric backend services.
• Develop and enhance rule definitions used for policy enforcement.
• Integrate with additional backend systems and maintain up‑to‑date API documentation through continuous documentation practices.
• Ensure high levels of automated test coverage using JUnit, Mockito, and BDD frameworks such as Cucumber.
• Take ownership of CI/CD pipelines, code quality standards, and service observability.

Mandatory experience includes:

• Strong experience building backend services using Java (17/21) and Spring/Core frameworks.
• Deep knowledge of JDBC, SQL parsing/validation, and query optimisation.
• Solid understanding of SQL query planning and execution paths.
• Strong grasp of data structures and algorithms.
• Robust testing skills, including JUnit5, Mockito, Cucumber, and designing deterministic tests.
• Proficiency in clean architecture principles, dependency injection, and modular service design.
• Familiarity with tooling such as Docker, Jenkins, Maven, and code‑quality tools (Checkstyle, Jacoco).

**Please note that we can not offer sponsorship for these position**