Java Developer - Contract

ROLE OVERVIEW

We are seeking an experienced Java Developer to join our Client's application modernization initiative. In this role, you will serve as the technical bridge between a legacy enterprise system and a modern, API-driven architecture - reverse-engineering existing JSP/Java applications, designing clean REST APIs, and guiding a cross-functional team through the transition. This position combines hands-on development with technical leadership, requiring someone who thrives in both deep technical work and cross-team collaboration.

MUST-HAVE SKILLS

The following competencies are essential for this role:

. Enterprise Java & Backend Frameworks

Strong proficiency in Java (Java 8+) and Spring ecosystem, including Spring Boot and Spring MVC

Hands-on experience with Hibernate, JPA, and designing scalable, maintainable enterprise solutions

Solid understanding of RESTful API design principles and enterprise integration patterns

. Enterprise DBMS - IBM DB2 (Preferred)

Solid experience with IBM DB2 or equivalent enterprise-grade RDBMS

Proficiency in writing complex SQL queries, performance tuning, and data modeling

Ability to analyse and map data structures in support of API and system design

. JSP & JSF - Legacy Application Experience

Working knowledge of JavaServer Pages (JSP) and JavaServer Faces (JSF)

Demonstrated experience maintaining, analysing, and extracting business logic from legacy web applications

GOOD-TO-HAVE SKILLS

. AWS Cloud Infrastructure - familiarity with core services such as EC2, RDS, S3, and Lambda

. Frontend Development - exposure to React and TypeScript, with experience working alongside UI development teams

. Design Collaboration - familiarity with Figma and the ability to participate meaningfully in UI/UX discussions

KEY RESPONSIBILITIES

Legacy Analysis & Technical Documentation

. Analyse and interpret legacy JSP UI and Java backend code to extract business rules and application logic

. Produce clear technical documentation including data flow diagrams, business rule registers, and API design artefacts

. Serve as the primary technical reference for understanding and articulating how the legacy system behaves

API Design & Development

. Design REST APIs to expose existing Java business logic to a modern React frontend

. Produce and own technical specifications including API request/response schemas, data mappings, and invocation flows

. Ensure all API designs align with enterprise standards, support reusability, and are well-documented

. Develop and enhance APIs with full implementation responsibility, from design through to testing

Testing & Quality Assurance

. Implement JUnit-based unit and integration tests to ensure code quality and adequate test coverage

. Perform code reviews and enforce coding standards across the team

Cross-Functional Collaboration

. Work closely with Business Analysts to finalise functional and technical designs, offering recommendations and alternatives where needed

. Support and guide React developers and BAs during development sprints and defect resolution

. Collaborate with designers via Figma during UI/UX discussions where applicable

Technical Leadership

. Own medium-to-large technical components end-to-end with minimal supervision

. Act as the primary technical point of contact for backend and API design decisions

. Proactively identify technical risks, design gaps, and improvement opportunities - particularly in legacy-to-modern transitions

. Contribute to and influence solution architecture discussions

. Mentor junior developers and foster a culture of quality and continuous improvement

EXPERIENCE & QUALIFICATIONS

. 5+ years of professional Java development experience in an enterprise environment

. Demonstrable experience leading technical components or workstreams on a team

. Strong background in legacy application analysis and modernisation projects

. Experience producing formal technical documentation (API specs, data mapping documents, design artefacts)

. Degree in Computer Science, Software Engineering, or a related discipline - or equivalent practical experience