Sebastian Perez

Develop and maintain TypeScript/React frontend features and Node.js/NestJS backend services for logistics and operational workflows used by Correos de Chile. Implemented finance/reporting capabilities including advanced filters, detail workflows, Excel exports and API integration across frontend and backend layers. Improved performance of slow status-filtering flows by normalizing status codes and refining repository/query logic while preserving expected UI behavior. Write and maintain automated tests with Jest and React Testing Library, resolve SonarQube findings and support code-quality and coverage requirements. Work with PostgreSQL, Docker, REST APIs and CI/CD-oriented development practices in a production enterprise environment.

Modernized legacy systems using React.js and Node.js and integrated AWS services including Lambda, API Gateway and serverless, contributing to lower operating costs. Designed ETL workflows with AWS Glue for large CSV/JSON/Parquet datasets (up to ~1 TB). Integrated Shopify APIs, React micro-frontends and Node.js/AWS Lambda services for e-commerce solutions. Applied TDD with Jest and React Testing Library, documented engineering processes in Confluence and contributed to Agile/Scrum planning. Built RESTful APIs and backend integrations focused on reliability, maintainability and user-facing performance.

Developed and improved the Afex Connect web/mobile platform using React.js, Angular, Node.js, React Native and AWS services. Built serverless components with Cognito, S3, CloudFront, SES, SNS, SQS and Amplify. Implemented real-time features with Socket.IO and optimized React rendering and interaction patterns. Worked across CI/CD, GitFlow, Jenkins, Scrum/JIRA and code-review practices; mentored junior developers.