Sử Nguyễn

Backend Software Engineer with 3+ years of experience in Golang and Ruby on Rails, specializing in reliable data pipelines, event-driven workflows, and multi-tenant architectures. Proven track record in optimizing PostgreSQL query performance across tables scaling to 10M+ records, building Kafka-driven event pipelines processing 3,500+ daily enterprise EDI files, and integrating LLM/RAG solutions. Experienced in developing greenfield services from scratch and modernizing legacy utilities for 60%+ execution speedups.

Software Engineer at Bestarion JSC (2023-09 – Present)

Greenfield, multi-tenant EDI processing platform designed to ingest, process, and manage EDI files through event-driven workflows, integrated within an enterprise Ruby on Rails ecosystem.

• Engineered an event-driven processing pipeline using Apache Kafka and Golang to process 3,500+ daily EDI files, cutting end-to-end processing and search-indexing time to under 20 seconds across isolated multi-tenant databases.
• Designed core backend services in Golang for a greenfield EDI platform supporting multi-tenancy with database-level isolation per organization.
• Implemented a custom orchestration layer to coordinate asynchronous EDI processing tasks according to configurable business rules, dependencies, and execution constraints.
• Built a configurable process pool to control concurrent workloads, orchestrate task execution, and prevent race conditions or conflicting jobs.
• Developed high-performance core APIs in Golang and integrated workflows with upstream Ruby on Rails services, leveraging batch processing, Redis caching, and OpenSearch.
• Implemented resilient failure-handling mechanisms, including transaction rollbacks, failure tracking, and structured logging for operational diagnostics.

Software Engineer at Bestarion JSC (2023-09 – 2025-09)

Large-scale healthcare supply chain management platform used by U.S. hospitals to manage medical supplies, process hospital-provided master data, and support purchasing and cost optimization.

• Modernized the Solr indexing pipeline by replacing a legacy Java utility with a Golang batch processor, reducing indexing time by 60% for large datasets.
• Optimized query latency and throughput across PostgreSQL tables scaling to 10M+ records, leveraging targeted indexing strategies, query restructuring, and intelligent batch-caching strategies.
• Designed asynchronous file-processing workflows between the intermediate Hub service and the Golang processing layer, decoupling large master file ingestion from the core Rails application.
• Maintained and developed core features across the Ruby on Rails monolith, Golang data services, and asynchronous background jobs (Delayed Job).
• Implemented an internal RAG-based knowledge assistant using RAGFlow and LLMs, streamlining documentation ingestion and accelerating engineering onboarding.
• Investigated and resolved production bottlenecks across application logic, PostgreSQL connections, search clusters, and background job lifecycles.

Bachelor of Engineering in Information Technology – Saigon University