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Open to new roles and projects · Medellín, CO
Juan Manuel
Vélez Parra
Java backend engineer building critical, high-volume systems for Colombia's financial sector, with Spring Boot, microservices, and Oracle.
- 5+years building critical financial systems
- 4financial institutions served, including BBVA and Banco de Bogotá
- 3transactional portals with OTP/2FA
- 3clients with e-invoicing for DIAN
I design and build the backend systems banks rely on every day: reliable, secure, and built to last.
Java backend engineer with 5+ years building critical, high-volume systems for the financial sector in Colombia. I work with Java 21, Spring Boot 3, WebFlux, microservices, and Oracle/PL-SQL, using hexagonal architecture, SOLID, and tests. I built the system that generates and sends encrypted monthly statements. I also delivered REST services, OTP/2FA for three transactional portals, and e-invoicing for DIAN. I handle the full cycle: requirements, design, code, tests, and deployment.
- Hexagonal architecture
- SOLID
- TDD
- DDD
- Event-driven architecture
- Clean Code
How I work
- Spec first (SDD): I define what to build and how to check it.
- Tests and review for every change.
- Tools: Claude Code and Cursor.
Where I've been shipping
Mar 2021 – Present
Software Engineer, Full Stack with a Backend focus
ITC Soluciones Tecnológicas
- Technology partner of Colombian financial institutions. Clients: BBVA, Credicorp, Banco de Bogotá, and Banco Popular.
- Professional role (Mar 2022 – Present): automated system that builds and sends encrypted monthly statements (Java/Spring, SOA with SOAP, and PL/SQL on Oracle).
- REST services and reports for the Fiduinversión portal (Angular/Spring).
- New features and OTP/2FA in three transactional portals.
- Electronic invoicing for DIAN (the Colombian tax authority) for three clients.
- Budget and invoicing modules in Oracle Forms 12c.
- Junior role (Mar 2021 – Mar 2022): SQL and PL/SQL tuning, reports in Oracle Forms and Reports, PL/SQL facade procedures for new Java web applications.
Aug 2019 – Mar 2021
Demand Planning and Analytics Professional
Línea Directa S.A.
- Python web scraping and Power BI dashboards to track e-commerce.
- Demand and supply planning.
- Price elasticity analysis with Excel macros.
Tools I use in production
From reactive APIs to the database, the whole backend path.
Languages
Java, Python, PL/SQL, JavaScript, HTML/CSS
Backend
Spring Framework, Spring Boot, Spring WebFlux (reactive), Hibernate/JPA, REST APIs, SOAP services, Oracle SOA, Jasper Reports
Messaging
Kafka
Build and testing
Maven, Gradle, JUnit, Mockito
Architecture and practices
Microservices, Event-driven architecture, Hexagonal/Clean Architecture, SOLID, TDD, DDD, Clean Code
Frontend
Angular
Databases
Oracle Database, PostgreSQL, PL/SQL
Cloud and DevOps
Oracle Cloud Infrastructure (OCI), WebLogic Server, Docker, Git, CI/CD
Tools and servers
Tomcat, JBoss, Jira, Confluence
Security
OTP and two-factor authentication (2FA)
Data and automation
Python (web scraping), Power BI, Advanced Excel (macros)
How I can help your team
Backend APIs and services
Backend APIs and services with Java and Spring Boot. Built for high volume, tested, and ready to deploy.
Integration and modernization
System integration and modernization with Oracle, PL/SQL, and SOAP/REST services.
Process and report automation
Process and report automation with Python and Power BI. Less manual work, better data.
Everything I build lives here
jotaeme.dev is the hub. Products, free tools, and experiments will each have their own subdomain.
- Coming soon
apps.jotaeme.dev
- Coming soon
Open apps
Free, non-profit web apps anyone can use.
free.jotaeme.dev
- Private
Lab
Self-hosted automation with n8n and personal experiments.
jotaeme.dev/lab