Full Stack Developer

Role purpose

You'll build cloud-native services and user interfaces for a multi-year programme modernizing a large portfolio of middle-office applications and moving them to AWS. This is a hands-on development role with a strong back-end focus. You'll design and build Java microservices and APIs on AWS, and also contribute to ReactJS/TypeScript front ends. You'll use AI coding tools such as GitHub Copilot, Claude Code and Devin every day to deliver faster, while staying fully accountable for the quality and security of the code.

Key responsibilities

Back-end development (primary)

• Design and build Java/Spring Boot microservices and REST APIs for trade processing, accounting, reconciliation and settlement functions.
• Build event-driven integrations with Kafka and IBM MQ, including message design, error handling, retries and idempotency.
• Write efficient data access against Oracle (JPA/Hibernate and SQL), working with database engineers on schema design and performance.
• Rebuild legacy business logic as clean, testable services, working with business analysts and subject-matter experts to confirm behaviour.
• Write unit, integration and contract tests, and help with performance and resilience testing.

AWS

• Build and deploy services on AWS: ECS/EKS, Lambda, API Gateway, S3, SQS/SNS, RDS, CloudWatch and IAM.
• Design services for scalability, high availability and security, following AWS Well-Architected principles.
• Work with DevOps on Terraform, Docker and CI/CD pipelines (Harness/GitHub Actions) so your services deploy automatically.

Front-end development (secondary)

• Build and maintain ReactJS/TypeScript screens and components for data-heavy enterprise applications that replace legacy desktop UIs.
• Connect front ends to back-end APIs, handling authentication (SSO/MFA), state management and error handling.
• Write maintainable JavaScript/TypeScript and component tests (Jest/React Testing Library).

AI-assisted development

• Use GitHub Copilot for inline code completion, chat-based refactoring, test generation and pull-request summaries.
• Use Claude Code for agentic, multi-file work in the terminal: understanding unfamiliar codebases, refactoring across modules, generating tests and fixing failing builds.
• Work with Devin (or similar autonomous agents) on well-defined tasks: write clear task specs, review its pull requests and correct its output.
• Use AI to analyse legacy code (Java EE, Sybase SQL, PowerBuilder, COBOL) and draft specs for subject-matter experts to confirm.
• Write good prompts and context files (e.g. README files, coding standards, agent instruction files) so AI tools produce code that follows team standards.
• Review all AI-generated code for correctness, security, performance and licence compliance before merging. You stay accountable for every line.
• Share effective prompts, patterns and lessons learned with the team.

Ways of working

• Take part in code reviews, design discussions and agile ceremonies.
• Support production releases, cutovers and early-life support, and fix issues quickly.
• Follow State Street secure coding, information security, data classification and approved-AI-tool policies.

Required experience and skills

• 6+ years in software development, mostly on the back end.
• Java: strong in Java 17+, Spring Boot, Spring Data/JPA, REST API design and multithreading.
• Messaging: practical experience with Kafka and/or IBM MQ.
• AWS: good hands-on knowledge of core services (ECS/EKS or Lambda, S3, SQS/SNS, RDS, IAM, CloudWatch).
• Databases: strong SQL; experience with Oracle or another enterprise relational database.
• ReactJS/TypeScript/JavaScript: good working knowledge of React hooks, component design, TypeScript and modern JavaScript (ES6+).
• AI tools: proven, regular use of at least one of GitHub Copilot, Claude Code or Devin in professional delivery, including the ability to judge when AI output is wrong.
• Engineering practices: Git, CI/CD, Docker, automated testing (JUnit, Mockito) and clean code principles.
• Experience working in agile delivery teams.

Preferred

• Hands-on experience with all three of GitHub Copilot, Claude Code and Devin, and a view on which tool suits which task.
• Experience with MCP servers or giving AI agents context from Jira, Confluence or code repositories.
• Experience in financial services, ideally investment servicing or middle-office areas (trade lifecycle, settlement, collateral, reconciliation or accounting).
• Experience modernizing legacy applications (e.g. Java EE/EJB on Payara or WebSphere, Sybase).
• Experience with Terraform and infrastructure-as-code.
• AWS Developer Associate or Solutions Architect certification.

Success measures (first 12 months)

• Delivered production-ready services and front-end features for modernized applications, on schedule.
• Services meet agreed standards for test coverage, performance, security and observability.
• Measurable productivity gains from AI tools (e.g. cycle time, test coverage), with no rise in defects or rework.
• Contributed reusable prompts, agent instructions or patterns that the wider team uses.
• Became a trusted contributor in design and code reviews across the team.

About State Street

Across the globe, institutional investors rely on us to help them manage risk, respond to challenges, and drive performance and profitability. We keep our clients at the heart of everything we do, and smart, engaged employees are essential to our continued success.

We are committed to fostering an environment where every employee feels valued and empowered to reach their full potential. As an essential partner in our shared success, you’ll benefit from inclusive development opportunities, flexible work-life support, paid volunteer days, and vibrant employee networks that keep you connected to what matters most. Join us in shaping the future.

As an Equal Opportunity Employer, we consider all qualified applicants for all positions without regard to race, creed, color, religion, national origin, ancestry, ethnicity, age, disability, genetic information, sex, sexual orientation, gender identity or expression, citizenship, marital status, domestic partnership or civil union status, familial status, military and veteran status, and other characteristics protected by applicable law.

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