Vaishnavi Katariya

Client: Mastercard (on-site)

• Working on a monolithic financial back-office system supporting transaction reconciliation, clearing, billing, and settlement reporting.
• Operating in a developer-owned delivery model, owning code changes, validation, and stability, with no separate QA team.
• Working with Spring Batch (XML-based configuration), understanding, and modifying job flows involving Tasklets, Partitioners, Listeners, and producer-consumer components.
• Writing and maintaining JUnit unit tests and integration tests to understand existing batch workflows, and validate backend code changes.
• Performing backend regression and performance validation of batch jobs to ensure data correctness and reliable execution.
• Analyzing and fixing Java code, SQL queries, and data-related issues identified during batch executions.
• Executing API and batch-level backend validations using the Karate framework for end-to-end processing.
• Managing code merges and branch synchronization, supporting stable backend releases.
• Collaborating directly with client stakeholders and internal teams, while maintaining enterprise-grade code quality.

• Developed RESTful backend services using Java 8 and Spring Boot for customer onboarding and customer validation workflows in lending and BNPL systems.
• Implemented database interactions using JOOQ, writing SQL queries for onboarding data persistence and reporting.
• Added API-level validations, centralized error handling and structured logging to improve customer onboarding flow reliability.
• Worked with basic AWS services (EC2, S3, CloudWatch) for application deployment and log monitoring.
• Debugged and resolved production issues related to onboarding failures, validation errors and data inconsistencies.
• Collaborated with team members through code reviews and followed clean coding practices in an Agile environment.

• Started as a fresher and contributed to unit testing using JUnit and Mockito, ensuring code quality and coverage.
• Progressively took ownership of backend development, designing and developing RESTful APIs with Spring Boot and Java 8.
• Worked on a microservices-based architecture, building and integrating independent services with a focus on scalability and loose coupling.
• Implemented database interactions using JPA/Hibernate and SQL stored procedures, with Java services invoking procedures for CRUD operations to improve maintainability and consistency.
• Designed and implemented a centralized exception handling and logging mechanism using @ControllerAdvice, significantly improving production issue debugging and error traceability.
• Refactored a tightly coupled service by extracting patient onboarding into a dedicated Patient microservice, separating it from test-ordering logic, and reducing code complexity.
• Actively handled production issues, performed root cause analysis, and delivered fixes within the SLA.
• Collaborated with cross-functional teams and followed Agile development practices, gaining end-to-end experience from development to production support.