Open to opportunities

Thais Contreras

@thaiscontreras

Message

I build secure, scalable Java microservices for payments, banking, and critical network platforms.

Dominican Republic

Message

What I'm looking for

I'm looking to build secure, scalable cloud-native services where clean code, robust testing, CI/CD automation, and practical AI solutions help solve complex business problems.

At Change Financial, I build secure Java services for Thales D1 card issuing, using JWE payload encryption and JWS message signing. I also help migrate monolithic legacy systems to Spring Boot microservices and design event-driven transaction services.

Previously, I improved Spring Boot microservice performance by 30% at Bertoni Solutions through optimized SQL and streamlined logic, while reducing technical debt by 30% with JUnit testing. At Banesco, I delivered card-management services that supported digital card issuance, payment management, and customer self-service.

At Claro DR, I built scalable network microservices, modernized data processing with Spring Batch and Python, created React interfaces, and maintained end-to-end CI/CD pipelines. I bring 7+ years of Java, Spring Boot, cloud-native development, testing, database optimization, and practical AI automation experience.

Experience

Work history, roles, and key accomplishments

Current

Payment System Developer

Current

Change Financial

Jan 2026 - Present (7 months)

Developed secure data exchange services in Java using JWE and JWS for compliant integration with the Thales D1 card issuing platform. Contributed to migrating legacy systems to Java Spring Boot microservices and co-developed an AI-powered time management tool.

Java Spring Boot Microservices Spring AI N8n Dovico API Event Driven Architecture

Backend Software Engineer

Bertoni Solutions

Jan 2024 - Jan 2026 (2 years)

Developed efficient Spring Boot microservices using Java/Groovy, improving system performance by 30% through optimized SQL queries. Reduced technical debt by 30% through JUnit testing and implemented custom Groovy scripts for pricing platform integration.

Java Groovy Spring Boot Microservices SQL Junit AWS PriceFX

Backend Software Engineer

Banesco

Sep 2023 - Jan 2024 (4 months)

Developed and integrated advanced card management services for digital card issuance and payment management in Spring Boot. Enhanced platform security and user experience by implementing robust backend logic for sensitive card operations.

Java Spring Boot Payment Systems Backend Development

Software Engineer

ClaroDR

Nov 2019 - Sep 2023 (3 years 10 months)

Developed scalable microservices for critical network infrastructure using Spring Boot and Spring Quartz, improving system reliability. Optimized performance by simulating peak loads with JMeter and modernized legacy systems with Spring Batch, PETL, and Python.

Java Spring Boot Spring Quartz JMeter Python TypeScript CI CD Jenkins

Software Developer

XpertCode

Jun 2019 - Nov 2019 (5 months)

Designed and implemented SOAP API CRUD operations for external user management, boosting operational efficiency by 25%. Built a Java web application using JSP and enhanced legacy code quality, reducing defects by 30% through SonarQube integration.

Java SOAP JSP SonarQube API Development CRUD