Leisurely exploring the software development world

Hello 👋, and welcome to my GitHub profile!

I'm Javier Feliu, an Engineering Manager and Senior Full-Stack Developer based in Panama City, Panama. I lead an 8-person engineering team at a private ad tech company, splitting my time between hands-on development and team leadership. I focus on building high-performance, scalable systems and helping teams deliver better software.

Areas of Expertise

• Distributed Systems & Performance
  Designed and built ultra-low-latency APIs with sub-50ms response times across multiple AWS regions, leveraging intelligent caching and cross-region deployment strategies for fraud detection and ad tech applications.

• Full-Stack Development
  Built and maintained large-scale web applications using Python (Flask, Django, Airflow), JavaScript (React, Express, Chrome Extensions), PostgreSQL, Redis, and modern cloud infrastructure (AWS, DigitalOcean, CloudFront).

• Process Automation & Orchestration
  Developed complex Airflow workflows that automate business processes, customer onboarding, and infrastructure updates. Built Chrome extensions with distributed task execution for automating operations across third-party platforms.

• Edge Computing & CDN
  Implemented CloudFront edge functions and KeyValueStore solutions for real-time request filtering and access control at scale, maintaining sub-millisecond performance across thousands of domains.

• Infrastructure & DevOps
  Maintained self-hosted Sentry for production monitoring and led major Jenkins CI/CD infrastructure overhauls. Experienced with Docker, declarative pipelines, and optimizing build processes.

• System Architecture & Documentation
  Designed complex features and integrations (Salesforce, GAM, Anthropic API). Created comprehensive technical documentation, including process diagrams and system architecture, to break down knowledge silos.

• AI-Driven Applications
  Built intelligent applications leveraging the Anthropic API for next-generation capabilities.

I enjoy solving complex technical challenges, designing scalable systems, and sharing knowledge with fellow developers. Thanks for stopping by—browse my repositories to see my work!

Let's connect on LinkedIn.