Senior Java Full Stack Developer

We are seeking a high-caliber Applications Development Technical Lead to spearhead the backend architecture and technical execution of our core Enterprise Vendor & Market Data Services Registry Platform in Belfast.

In this pivotal role, you will serve as the senior technical anchor for our Belfast engineering team—driving technical strategy, system architecture, and modern engineering practices while remaining hands-on with mission-critical Java microservices and complex data pipelines. You will collaborate closely with global engineering counterparts, product managers, and enterprise architects to deliver high-throughput data reconciliation, automated ingestion, and robust REST APIs.

If you are an experienced senior backend technologist who thrives on building scalable distributed data systems, mentoring talented engineers, and leveraging modern GenAI tools (e.g., Devin, GitHub Copilot, Cursor) to drive high engineering velocity, this role offers an exceptional platform for technical leadership and impact.

Key Responsibilities & Technical Leadership:

Architectural Stewardship & Hands-On Engineering

• Architect, design, and deliver high-performance, resilient Java (21/25) and Spring Boot microservices powering core enterprise data ingestion, deduplication, and reconciliation engines.

• Lead the design and implementation of relational data models, audit trails, and transactional staging pipelines handling complex multi-source data feeds (billing, contracts, and organizational hierarchies).

• Define, build, and maintain clean, secure, and well-documented RESTful APIs supporting internal maintenance workbenches and downstream analytical consumers.

• Champion cloud-native deployment patterns across containerized platforms (Docker, OpenShift / Kubernetes) with CI/CD automation and strict security governance.

Strategic Engineering Leadership & Team Mentorship (Indirect Platform Lead)

• Act as the senior engineering authority for the Belfast development hub, shaping technical roadmaps and setting high benchmarks for code quality, architectural integrity, and automated testing.

• Mentor and coach mid-level and senior engineers (C11/C12), fostering a culture of continuous learning, technical autonomy, and engineering excellence.

• Partner closely with global product management, domain analysts, and solution architects to translate complex business requirements into clear, phased technical deliverables.

• Drive rapid engineering and innovation by integrating autonomous AI-assisted development tools (such as Devin, GitHub Copilot, and Cursor) across the software development lifecycle.

Full-Stack Awareness & End-to-End Ownership

• While heavily focused on backend architecture and data systems, provide architectural oversight across the full application stack, collaborating effectively with frontend engineers building modern React/TypeScript maintenance interfaces.

• Ensure seamless end-to-end integration, predictable API contracts, and consistent telemetry/monitoring across all tiers.

Technical Profile & Qualifications:

Required Technical Skills:

• 7+ years of hands-on software engineering experience with deep expertise in Modern Java (Java 21/25) and the Spring Ecosystem (Spring Boot, Spring Data, Spring Security).

• Data Engineering & Architecture: Strong experience with relational databases (Oracle, PostgreSQL), complex SQL, schema design, data deduplication, batch/stream processing, and transaction management.

• Distributed Systems & API Design: Proven track record designing enterprise RESTful APIs, microservices architectures, and event-driven patterns.

• Modern DevOps & Tooling: Solid experience with Git, Maven/Gradle, automated CI/CD pipelines (Tekton, Jenkins), containerization (Docker, OpenShift/K8s), and automated testing frameworks (JUnit 5, Mockito, Testcontainers).

• AI-Accelerated Engineering: Active practitioner or champion of AI coding assistants (Devin, Copilot, Cursor) to accelerate prototyping, code generation, and test coverage.

Leadership & Soft Skills:

• Demonstrated experience acting as a lead engineer, technical authority, or architectural mentor within enterprise or high-scale environments.

• Excellent communication skills with the ability to articulate complex technical trade-offs to senior business and technology stakeholders.

• Strong pragmatic problem-solving skills with a focus on delivering incremental business value.

Nice-to-Have / Valuable Extras:

• Familiarity with modern frontend ecosystems (React, TypeScript, State Management) and end-to-end UI-to-backend integration.

• Exposure to Market Data systems, financial data models, or vendor contract management domains.

• Experience with high-performance analytics engines or in-memory data processing (DuckDB, Parquet, Kafka).

Education & Experience

• Bachelor’s / Master’s degree in Computer Science, Software Engineering, or equivalent practical experience.

• Track record of technical delivery and leadership in mid-to-large scale enterprise technology organizations.

What we offer:

We work hard to have a positive financial and social impact on the communities we serve. In turn, we put our employees first and provide the best-in-class benefits they need to be well, live well and save well.

By joining Citi Belfast, you will not only be part of a business casual workplace with a hybrid working model (up to 2 days working at home per week), but also receive a competitive base salary (which is annually reviewed), and enjoy a whole host of additional benefits such as:

• Generous holiday allowance starting at 27 days plus bank holidays; increasing with tenure

• A discretional annual performance related bonus

• Private medical insurance packages to suit your personal circumstances

• Employee Assistance Program

• Pension Plan

• Paid Parental Leave

• Special discounts for employees, family, and friends

• Access to an array of learning and development resources

Alongside these benefits Citi is committed to ensuring our workplace is where everyone feels comfortable coming to work as their whole self every day. We want the best talent around the world to be energized to join us, motivated to stay, and empowered to thrive.

Sounds like Citi has everything you need? Then apply to discover the true extent of your capabilities.

#LI-KK5

This job description provides a high-level review of the types of work performed. Other job-related duties may be assigned as required.

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Job Family Group:

Technology

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Job Family:

Applications Development

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Time Type:

Full time

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Most Relevant Skills

Please see the requirements listed above.

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Other Relevant Skills

For complementary skills, please see above and/or contact the recruiter.

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