- Payment (payment flow management service):Maintained and implemented new APIs for payment flow at GHTK.Integrated with the bank to implement a write-note flow for shops transferring money to GHTK bank accounts.- Ops Service (operational and customer care support service):Maintained, optimized, and implemented new APIs for services that help sale and customer care staff work more effectively.- moshop (management and sales platform for shops):Maintained and wrote APIs for social chat service.Implemented and optimized new APIs for order management and customer support for moshop.- Gmap (internal map service):Wrote APIs for address management using Event Sourcing and CQRS design.Designed and wrote an ETL process to import global OSM data to GHTK's OSM data.Designed and wrote a tokenizer for Vietnamese addresses.Maintained data and customized GraphHopper logic to align with GHTK's business needs.

- Projects: Core Platform, CRM app for Sales, Nextshop2- Responsibilities: Maintained and optimized old codebases, implemented new features, and wrote documentation