Carlos Ceballos

Full Stack Web Developer

GEH Suites Hotels • Full time

Feb 2025 - Jun 2026 • 1 yr 4 mos

Backend & Databases Scaled, maintained and extended the API of Booking Connect, the company's B2B hotel availability and booking platform (NestJS + MongoDB), used by 1,000+ travel agencies and 1,400+ active users, including a complete flight-booking API. Designed, modeled and optimized PostgreSQL relational databases (schemas, advanced SQL queries and indexing) for the company's internal systems: multi-hotel expense management and hotel occupancy ETL. Developed robust, scalable RESTful APIs with Django REST Framework and NestJS, improving integration between internal and external systems. Built daily ETL processes in Python and PostgreSQL to process hotel occupancy data from multiple sources, with real-time statistical reporting. Designed and implemented a multi-hotel financial expense management system (13 properties) with expense tracking, petty-cash management, real-time statistics and automated PDF and Excel reports, backed by PostgreSQL (Django REST Framework). Automated administrative invoicing processes with an RPA bot (invoice extraction from email, CRM registration and attachment upload), reducing operating time by 40%. Refactored legacy code and optimized backend processes, improving overall platform performance and scalability. Frontend Developed modern, responsive, high-performance interfaces with React, Astro and Tailwind CSS for Booking Connect and the internal systems, focused on usability for 1,400+ active users. Mobile Development Designed and developed a cross-platform (iOS/Android) Flutter app for travel agencies that operate mainly from mobile devices, streamlining their on-the-go booking flows. Developed an Android TV app with Flutter integrating vir