Daeseon Yoo
Backend & AI Engineer · Toronto, Canada
Open to roles · Remote or Toronto
Backend engineer with 5+ years building and modernizing mission-critical enterprise systems across manufacturing, warehouse, and financial operations. Strong in backend logic, SQL/PL-SQL, transaction design, and cross-system integration. Currently focused on Java/Spring backend platforms and AI-assisted product engineering — reliable backends plus practical AI-powered tools.
Currently
- SK AX, Toronto (Sep 2021 – present). Java/Spring + AI-assisted product engineering.
- Building the Daeseon AI Factory — reusable backend and AI cores for shipping product faster.
- Open to senior / staff backend or AI engineer roles. Remote or Toronto local.
- What I'm on right now lives at /now.
Previously
SK AX · Software Engineer
Sep 2021 – May 2026
Manufacturing cost management system, enterprise mobile web platform across 8 sites, and real-time MES. Backend Java/Spring, PL/SQL on Oracle, transaction redesign across financial systems.
Dure Info · Software Developer
Jun 2020 – Sep 2021
Solved a critical data-loss bug from network packet fragmentation by implementing a custom buffering layer (MemoryStream) with application-level protocol validation.
Selected impact
- Refactored the PL/SQL costing core from ~7,000 to ~3,000 lines; weekly ticket throughput 4 → 7.
- Consolidated 40 endpoint-specific middleware APIs into a single common gateway. $100K+/year in operational savings.
- Redesigned transaction boundaries between manufacturing operations and financial systems using a staging-table + batch-worker pattern. Processing time -60%, reprocessing 20 monthly cases → near zero.
- Implemented a custom database-backed locking mechanism to prevent duplicate costing jobs across multiple application instances.
- Optimized real-time MES equipment message handling to meet a strict 4-second timeout SLA.
Writing about
- LLM systems patterns — RAG, evals, tool use, agent loops (LangGraph).
- Backend systems — transaction design, locking, cross-system integration.
- Project recaps in the before / change / result / limit format.
Stack
- Languages
- Java, Python, SQL/PL-SQL, C#, TypeScript
- Backend
- Spring Boot, FastAPI, REST APIs, .NET
- Frontend
- Next.js, React
- AI / LLM
- RAG, Agent Workflows, LangGraph, AI-assisted dev
- Databases
- PostgreSQL, MongoDB, Oracle
- Infra
- Docker, Docker Compose, Git, Linux, AWS basics, CI/CD
Education
M.S. & B.S. in Industrial Engineering · Kumoh National Institute of Technology, Gumi, South Korea (2012–2019).