David Crespo

I develop end-to-end systems to automate workflows involving large volumes of data in real time.
What I do:
-24/7 Scraping and Monitoring — I extract information from APIs, websockets and web sources, with anti-duplication systems and concurrency management.
- Real-time processing — Intelligent filters, automatic scoring, pattern detection, and action execution based on configurable rules.
- Interactive dashboards — Web interfaces with live data, pivot tables, performance charts, and auditable logs.
- Integration with external systems — REST APIs, WebSockets, OCR processing, local persistence, and backups.
- No heavy dependencies — Pure HTML/CSS/JS development, ready to deploy to any server or even use locally.
Technologies: Modern JavaScript, WebSockets, REST APIs, OCR (Tesseract), local storage (IndexedDB/localStorage), real-time scoring algorithms.
Use cases:
Price monitoring and automatic execution of actions
Processing handwritten lists from photos
Indicator dashboards with multiple data sources
Alert systems with multi-criteria filters