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🚀 Sergio Roa

Semi-Senior Full-Stack Developer

✨ About Me

Full-Stack Developer with 5 years of experience specialized in delivering robust and scalable systems. My strength lies in backend with PHP (Laravel) and Java (Spring Boot), complemented by Angular and React on the frontend.

I combine corporate discipline with a comprehensive product vision that allows me to:

  • Lead and Mentor: I guide teams through code reviews, task planning, and technical mentorship
  • Align Technology with Business: I translate stakeholder requirements into solutions that generate commercial value
  • Optimize Performance: My experience in Embedded Systems (C/C++) enables me to design efficient APIs and optimized code

🛠 Tech Stack

Backend
🐘 PHP (Laravel) | ☕ Java (Spring Boot) | 🐍 Python (FastAPI) | 💻 C/C++ | 💻 C#

Frontend
⚡ JavaScript/TypeScript | Angular | React

Databases
🗄 MySQL | PostgreSQL | SQL Server

DevOps & Cloud
🐳 Docker | 🧰 Git | ☁️ AWS (EC2, S3, RDS) | ☁️ GCP (VMs, Cloud Storage)

🌟 Key Achievements: Critical Systems and Automation

1. 🚀 Performance Optimization and Operational Capacity

  • Performance Transformation (KPI): I optimized crucial queries in Laravel (migrating from API Handler to ORM), reducing result size from 10 MB to 1.2 MB and response time from 15 seconds to 2-3 seconds.
    • Impact: This optimization resolved server saturation (physical), enabling remote work for staff and unlocking capacity for the development of new critical modules.

  • Cost Savings and Cloud Migration (15-20%): I designed and implemented a hybrid storage system (Local + GCS/GCP), migrating 1 TB of data without loss. This generated a 15-20% cost savings by reducing instance disk space.

  • Leadership in Critical Backend Migration: I executed the migration of 70% of the backend (developed with Java/Spring Boot) from a poorly structured DynamoDB-based system to a robust relational solution (RDS). This refactoring ensured data integrity, querying, and scalability.

2. ✅ Leadership in Hiring Automation (Quantified Savings)

  • Hiring Acceleration and Self-Service Portal: I implemented a high-volume Candidate Portal that centralized data and document uploads. This eliminated a critical bottleneck and resulted in a 20% reduction in processing time for Psychology and HR.
  • Automatic Integration and Efficiency (30% Savings): I created the integration for automatic transfer of data, documents, and procedure results between different systems used by the company. This reduced manual processing by 30%, allowing teams in some cases to start with 25% of work already completed in each hiring process.
  • Mass Synchronization Script and Compliance: I developed a script that processed a Payroll Excel to identify and automatically create thousands of missing contract records in the system (requisition, operation, contract). This resolved a critical integrity and compliance issue by ensuring all information and documentation existed on the platform.

3. 🛡️ Risk Mitigation and Internal Control

  • Vendor Replacement and Mass Usage (Sick Leave Module): I led the development of the Sick Leave module, replacing an expensive third-party application. This module is used by thousands of people (via login and public URL) and includes automatic notifications (WhatsApp), generating direct savings and a substantial improvement in management.

  • Replacement and Automation of Medical Exams: I led the development of a medical exam referral module that replaced a third-party platform that was failing. The automation of orders, emails, and WhatsApp notifications resulted in a 50% time savings for the medical process manager and provided financial control to Accounting.

  • Legal Risk Mitigation (Medical Cases): I developed the Medical Cases module, centralizing documentation and tracking (HSE). This mitigated lawsuit risks that the company faced due to lost documentation and lack of legal follow-up.

  • Real-Time Auditing and Management: I created critical reports (in real-time) for hiring tracking. These reports overcame the slowness of the existing BI and incorporated complex business logic for internal auditing.

  • Extreme Frontend Modernization: I executed the complete update of React (v2020 to v19) and Angular, the partial update (v2 to v19), ensuring maintainability, performance, and compliance with best practices.

Note: You can find details of these and other additional achievements (such as modernization, inventory, mass candidate uploads, and internal tools) in the Professional Experience file.

📂 Explore My Work

📋 Professional Experience
Detailed trajectory and technical evolution

💻 Skills & Technologies
Complete stack and proficiency level

🎯 Projects
Real use cases and end-to-end development

🎯 My Approach

✅ Quickly understand business rules and how technology adds value
✅ Write clean, maintainable, and scalable code
✅ Modernize legacy projects without compromising operations
✅ Contribute to team growth through mentorship and best practices
✅ Take on complex technical challenges that drive my continuous learning

Looking for a developer who combines technical expertise with business vision?
Check out my projects to see my work in action.