Open to opportunities

Julian Santiago Rangel Manrique

@santiago_rangel

Message

Full-stack developer focused on Java Spring Boot and React, building scalable backend and cloud-ready systems.

Colombia

Message

What I'm looking for

Busco aportar mis conocimientos en desarrollo Backend y continuar mi crecimiento profesional en tecnologías Cloud (AWS), integrándome a equipos ágiles para construir sistemas escalables, bien documentados y probados.

I’m a Systems Engineering student (esperadegrado) who consolidates practical experience developing software, with a strong focus on Java (SpringBoot) and competencies in Python. I’ve built scalable architectures using Hexagonal Architecture, containerized services with Docker, and worked with multiple databases like PostgreSQL.

I’m autodidact and proactive, with proven ability for remote work and integration in agile teams. I’ve delivered backend and fullstack features such as Keycloak user management, Swagger-documented endpoints, JWT-based auth, and REST API integrations—backed by testing with JUnit/Mockito plus tools like Postman and Selenium, and I’m currently seeking to continue growing professionally in Cloud (AWS).

Experience

Work history, roles, and key accomplishments

Freelance Fullstack Dev

Independiente / Freelance

Jun 2025 - Oct 2025 (4 months)

Developed a web site using Java (Spring Boot) and React, integrating Keycloak for user management. Documented endpoints with Swagger and implemented an hexagonal architecture approach.

Java Spring Boot React Keycloak Hexagonal Architecture REST APIs

Freelance Backend Developer (PHP)

Independiente / Freelance

Jan 2025 - May 2025 (4 months)

Built a backend for a web application in PHP and integrated external APIs to handle data. Generated PDF/XLSX/CSV outputs from the backend and debugged endpoints with Postman.

PHP Backend Development Postman CSV XLSX Generation

Freelance Backend Developer (Spring)

Independiente / Freelance

Nov 2024 - Jan 2025 (2 months)

Validated a REST API built with Spring Boot and produced Swagger-based API documentation. Worked remotely to ensure the API functionality matched requirements.

Java Spring Boot REST APIs API Documentation Backend Development Testing

Freelance Fullstack Developer

Independiente / Freelance

May 2024 - Dec 2024 (7 months)

Developed a web platform using Angular 17+, NestJS, Docker, and JWT for secure authentication. Built responsive UI components (Bootstrap) and implemented relational data storage with PostgreSQL, with unit/functional and E2E testing using Selenium and Postman.

NestJS Docker JWT PostgreSQL Bootstrap ApexCharts Swiper Selenium Postman

Academic Technical Mentor

Universidad Santo Tomás

Feb 2023 - Dec 2024 (1 year 10 months)

Mentored advanced-semester students with technical guidance on developing and deploying REST APIs using Spring Boot and Docker. Helped implement JWT authentication and Express APIs as part of course activities.

Mentoring Spring Boot Docker REST APIs JWT API Deployment