Full-Stack Java Developer with Spring Boot Expertise

Leyki Reyonoso Jr Maywood, NJ

210-***-**** *****@************.*** https://www.linkedin.com/in/leyki-reynoso-jr-b0b9a5141

PROFESSIONAL SUMMARY:

Full Stack Java Developer with experience supporting enterprise and financial applications, working across backend services and frontend interfaces.

Hands-on experience developing Spring Boot–based REST APIs and implementing persistence logic using Hibernate and JPA.

Experience working within microservices-based architectures, supporting service communication, configuration, and scalability.

Skilled in building and maintaining React-based user interfaces, integrating secure authentication and responsive UI components using Bootstrap.

Practical exposure to relational and NoSQL databases, supporting transactional data processing and application workflows.

Familiar with cloud platforms, CI/CD pipelines, and containerized environments, supporting automated builds and deployments.

Background includes enterprise, academic, and research environments, contributing strong problem-solving, collaboration, and documentation skills.

TECHNICAL SKILLS:

Backend & Enterprise Development

Java, Spring Boot, Hibernate, JPA, REST APIs, Microservices, RabbitMQ

Frontend & UI Development

React Native, HTML, CSS, JavaScript, Bootstrap

Databases & Data

PostgreSQL, MongoDB, SQL, Spark

Cloud & DevOps

AWS, Docker, Jenkins, Maven, Git

Mainframe & Enterprise Systems

RACF, z/OS, TSO/ISPF, SDSF, JCL, REXX, COBOL, DFSMS, SMP/E, CICS, IMS, JES2

Testing & Tools

JUnit, Mockito, Postman

Messaging:

Kafka, RabbitMQ, JMS

Servers:

Apache Tomcat, WebLogic, JBoss, WebSphere

Platforms:

Windows, Linux, macOS, UNIX

PROFESSIONAL EXPERIENCE:

Full Stack Java Developer Aug 2023 – Present

Fiserv

Design and develop Spring Boot–based RESTful APIs to support secure financial transaction processing and service-to-service communication.

Implement backend business logic using Hibernate and JPA, ensuring data integrity, validation, and transactional consistency.

Implement JWT-based authentication and authorization, securing user sessions and API access across applications.

Contribute to a microservices-oriented architecture, supporting service isolation, scalability, and maintainability.

Deploy and manage services on AWS, using Docker containers scripts to standardize environments.

Develop and maintain CI/CD pipelines using Jenkins and Maven to automate builds, testing, and deployments.

Integrate PostgreSQL and MongoDB to support both structured financial data and flexible application data models.

Implement event-driven workflows using Kafka and RabbitMQ to support asynchronous processing across systems.

Collaborate within Agile Scrum teams, participating in sprint planning, code reviews, retrospectives, and cross-team coordination.

Environment: Java 11, Spring Boot, Hibernate, JPA, Microservices, Bootstrap, JWT, PostgreSQL, MongoDB, Kafka, RabbitMQ, AWS, Docker, Jenkins, Maven, JUnit, Postman

Software Developer Sep 2022 – Jul 2023

ScanAvert Newark, NJ

Developed a React Native barcode-scanning feature, integrating external APIs and FDA food databases for real-time product insights.

Implemented backend integrations to support nutrition data retrieval and safety analysis.

Upgraded application dependencies and navigation libraries to improve stability and maintainability.

Identified and resolved performance issues through profiling, debugging, and code optimization.

Collaborated with designers and backend engineers to ensure consistent feature delivery.

Laboratory Technician Mar 2022 – Mar 2023

New Jersey Institute of Technology Newark, NJ

Supported IT infrastructure for classrooms and laboratories, ensuring secure and reliable technology access.

Assisted students and faculty with system access, troubleshooting, and hardware setup.

Performed preventive maintenance to reduce downtime and improve overall system reliability.

Coding Tutor Feb 2023 – Jul 2023

theCoderSchool Montclair, NJ

Taught Python and Scratch, adapting lessons to different learning levels and student needs.

Designed interactive coding exercises to strengthen logical thinking and problem-solving skills.

Mentored students individually, helping them overcome programming challenges and achieve milestones.

Researcher May 2019 – Sep 2020

Bergen Community College Paramus, NJ

Led development of a facial recognition application for home security use cases.

Coordinated a student team to meet research goals, timelines, and technical deliverables.

Presented project outcomes to faculty and administrators, highlighting applied AI concepts.

Tutor Sep 2019 – Sep 2020

Bergen Community College Paramus, NJ

Tutored mathematics and computer science subjects including C++ and data structures.

Helped students strengthen analytical thinking and problem-solving techniques.

Participated in tutor training workshops to improve instructional effectiveness.

EDUCATION:

New Jersey Institute of Technology Bachelor of Science — Computer Science May 2023

Bergen Community College Associate of Science — Computer Science June 2020

CERTIFICATIONS:

Oracle Certified Java SE 8 Developer – May 2025

IBM Z Xplore – All Star (Enterprise Computing, COBOL, JCL, REXX, RACF, z/OS)

IBM z/OS REXX Programming

Google Data Analytics Specialization

Data Scientist Career Path – Machine Learning

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