App Development Jobs in Jacksonville, FL (NOW HIRING)

Join our high-impact Test Data Management team, a group dedicated to building and maintaining the essential tools that empower dozens of scrum teams to test their customer-impacting changes safely and efficiently. Our core mission is to automate and streamline the complex process of managing test data at a massive scale. As a Senior Application Developer, you will be a full stack engineer responsible for designing, building, and supporting the modern web applications that form our self-service toolset.

This role requires expertise across the stack, from front-end development in React to back-end services in Java/Spring Boot. You will be instrumental in our ongoing effort to consolidate and modernize our applications, creating a more efficient workflow for the entire organization within an API-first, microservices-based architecture. If you are passionate about automation, building thoughtful interfaces, and creating solutions that make developers' lives easier, this is the team for you.

Key Responsibilities Full-Stack Development: Design, build, and support modern, user-friendly web applications across the stack (UI, APIs, and backend services) to provide self-service test data capabilities. Backend & API Services: Develop scalable, secure microservices using Java and Spring Boot. Design, build, and document RESTful APIs, ensuring adherence to service contracts and versioning strategies.

Automation & Modernization: Design and implement automated processes for provisioning and managing test data accounts. Actively contribute to the consolidation and modernization of our internal toolset to improve efficiency and user experience. Collaboration & Custom Solutions: Work closely with development teams to understand their needs and provide customized test data solutions where required.

Engineering Excellence: Utilize GitHub and contribute to automated CI/CD pipelines for building, testing, and deploying applications. Promote engineering best practices by writing robust unit and integration tests and participating in code reviews. Support & Operations: Perform standard test data management functions to ensure the reliability and availability of test data for all scrum teams.

Required Skills & Qualifications 5+ years of experience in full-stack web application development. Strong backend development experience with Java and Spring Boot (REST APIs, security concepts, performance, and scalability). Strong front-end development experience with React, including TypeScript, HTML5, and CSS.

Solid understanding of API design and microservices architecture (service boundaries, resilience, observability basics). Hands-on experience with SQL Server and relational data modeling. Proficiency with GitHub workflows and practical experience with CI/CD pipelines.

Excellent communication skills, a strong sense of ownership, and the ability to work collaboratively in an agile team. Preferred Skills Experience with cloud platforms (AWS, Azure, or GCP). Experience with Node.js

Containerization and orchestration experience (Docker, Kubernetes/OpenShift). Experience with a variety of automated testing frameworks (unit, integration, and UI testing). Exposure to observability practices (logging, metrics, tracing) and production support.

Education Bachelor's degree in Computer Science, Software Engineering, a related technical field, or equivalent practical experience ------------------------------------------------------ Job Family Group: Technology ------------------------------------------------------ Job Family: Applications Development ------------------------------------------------------ Time Type: Full time ------------------------------------------------------ Primary Location: 14000 CITI CARDS WAY BUILDING C JACKSONVILLE ------------------------------------------------------ Primary Location Full Time Salary Range: $113,840.00 - $170,760.00 In addition to salary, Citi's offerings may also include, for eligible employees, discretionary and formulaic incentive and retention awards. Citi offers competitive employee benefits, including: medical, dental & vision coverage; 401(k); life, accident, and disability insurance; and wellness programs. Citi also offers paid time off packages, including planned time off (vacation), unplanned time off (sick leave), and paid holidays

For additional information regarding Citi employee benefits, please visit citibenefits.com. Available offerings may vary by jurisdiction, job level, and date of hire. ------------------------------------------------------ Most Relevant Skills Please see the requirements listed above

------------------------------------------------------ Other Relevant Skills For complementary skills, please see above and/or contact the recruiter. ------------------------------------------------------ Anticipated Posting Close Date: Jul 15, 2026 ------------------------------------------------------ Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law. If you are a person with a disability and need a reasonable accommodation to use our search tools and/or apply for a career opportunity review Accessibility at Citi.

View Citi's EEO Policy Statement and the Know Your Rights poster.