Java Full Stack Developer

Citi Group; Belfast City District; Hybrid; GBP 70,000 - 110,000; Full time

Benefits offered by this job

Generous holiday allowance

Annual performance bonus

Private medical insurance

Employee Assistance Program

Pension Plan

Paid Parental Leave

Learning and development resources

Job summary

Citi Belfast is seeking a Senior Java Backend Engineer to build scalable backend services and ingestion pipelines for VMC, an enterprise-scale registry platform. You will own REST APIs, collaboration with frontend teams, and apply GenAI tooling to accelerate development.

The role emphasizes high-throughput design, robust data models, and strong testing culture within a hybrid, globally-collaborative environment.

Qualifications

• Bachelor's degree in Computer Science or related field.
• Strong Java and Spring Boot experience.
• Proven experience designing RESTful APIs and microservices.
• Experience with relational databases and SQL optimization.
• Experience with data ingestion, ETL, or batch processing pipelines.
• Solid testing discipline and familiarity with JUnit/Mockito.
• Familiarity with CI/CD pipelines and Docker-based deployments.

Responsibilities

• Design, build, and maintain production-grade REST APIs and microservices using Java 21/25 and Spring Boot.
• Build resilient ETL and reconciliation services ingesting monthly datasets from multiple upstream sources.
• Design relational schemas and optimize SQL queries with transactional integrity and audit logs.
• Collaborate with frontend teams to integrate APIs with data grids and bulk workflows.
• Leverage GenAI tooling for rapid prototyping, scaffolding, and test generation.
• Maintain high code quality with TDD/BDD and automated CI/CD pipelines.
• Mentor engineers across global teams and take ownership within the Belfast squad.

Skills

Java

Spring Boot

RESTful APIs

Microservices

SQL databases

ETL/Data ingestion

CI/CD

JUnit/Mockito

Docker

Git

Linux

Education

Bachelor's degree in Computer Science or related field

Tools

PostgreSQL

Oracle

MySQL

Kafka

Testcontainers

Jenkins

Tekton

Maven

Gradle

Docker

Git

Linux

Job description

We are looking for a Senior Java Backend Engineer (C12) in Belfast to join the core engineering team building Vendor Master Central (VMC) -an enterprise-scale registry platform responsible for ingesting, reconciling, and managing millions of market data service records, contracts, and vendor hierarchies.

This role is backend-first , centered on designing high-throughput ingestion pipelines, resilient Spring Boot microservices, clean RESTful APIs, and domain data models. Experience or interest in Full Stack development with React/TypeScript is a strong plus , enabling end-to-end feature ownership from backend services up to user-facing web tools.

We actively embrace GenAI-assisted engineering (Devin, GitHub Copilot, Cursor) to automate boilerplate, accelerate unit testing, and achieve high engineering velocity.

Key Responsibilities:

• Backend Microservices: Design, build, and maintain production-grade REST APIs and microservices using Java 21/25 and Spring Boot .
• Data Ingestion & Processing: Build resilient ETL and reconciliation services that ingest, validate, and deduplicate complex monthly datasets from multiple upstream sources into a unified data model.
• Data Modeling & Storage: Design relational schemas (PostgreSQL / Oracle), optimize complex SQL queries, and implement transactional data integrity, staging layers, and immutable audit logs.
• Full Stack Collaboration (Bonus): Partner with or contribute to the React/TypeScript frontend to integrate APIs seamlessly with data grids, curation drawers, and bulk Excel upload workflows.
• GenAI Velocity: Leverage AI-powered developer tooling (Devin, Copilot, Cursor) for rapid prototyping, component scaffolding, and automated test coverage.
• Engineering Excellence: Drive high code quality through TDD/BDD (JUnit 5, Mockito), automated CI/CD pipelines, containerization (Docker/OpenShift), and code reviews.
• Mentorship & Ownership: Act as a technical pillar within the Pune agile squad, collaborating with global teams and mentoring junior engineers.

What We Are Looking For:

Core Backend Requirements:

• 5-8+ years of hands-on software development experience with core focus on Java (21/25) and Spring / Spring Boot .
• Strong foundation in RESTful API design , microservice architecture, and enterprise integration patterns.
• Deep expertise in relational databases (SQL) , schema design, data indexing, transactions, and performance tuning (PostgreSQL, Oracle, or MySQL).
• Solid experience building data ingestion, transformation, or batch processing pipelines .
• Strong testing discipline: unit testing, integration testing, and mock frameworks (JUnit, Mockito, Testcontainers).
• Experience with modern DevOps pipelines (Git, Maven/Gradle, Jenkins/Tekton, Docker, Linux).

Nice-to-Have / Full-Stack Plus:

• Experience or familiarity with React, TypeScript, or modern frontend SPAs (state management, component design, data grids).
• Familiarity with client/server Excel file processing (.xlsx generation, bulk upload parsing).
• Experience working with autonomous AI engineering agents (e.g., Devin ) or AI-assisted coding tools.
• Experience with message brokers or event streaming (Kafka, MQ).

Qualifications & Competencies

• Education: Bachelor's degree in Computer Science, Software Engineering, or equivalent practical experience.
• Autonomy & Judgment: Ability to operate with limited direct supervision, make sound architectural choices, and deliver features independently.
• Communication: Strong English communication skills and ability to collaborate across distributed global teams (India, UK, US).
• Risk & Controls: Sound understanding of secure coding practices, data governance, and enterprise security standards.

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

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 everythi