// software engineer
Hi, I'm Jace.
CS undergrad student (final year) at Soongsil University and a software engineer. I'm focusing on backend and cloud systems — interested in virtualization, observability, and stable distributed system.
Experience
Cloud System SW Engineer Intern · Boeing Korea
Cut core table-view API latency 42% on an ASP.NET/EF backend and sped up graph rendering 20%. C# · Python · SQL Server
Python Backend Developer Intern · PTKOREA
Built a 750+ test pipeline from scratch, lifting coverage to 76% on a FastAPI backend. Python · FastAPI · PostgreSQL
Backend Developer / DevOps · Soongsil Univ. ITSupport (student club)
Backend and cloud infrastructure for the university IT committee. Go · Python · Rust · SpringBoot · AWS · Terraform
Undergraduate Researcher · System Software Lab, Soongsil Univ.
FastAPI backend with async AI workflows (Celery) for a font-generation platform. Python · Celery · Redis
Projects
Container runtime
A from-scratch container runtime in Rust that isolates the filesystem, processes, and resources using Linux namespaces, cgroups v2, and pivot_root.
Rust · Linux · cgroups v2Single Sign-On service (private)
Serverless SSO for the club’s services using AWS Cognito; migrated Python → Go to cut Lambda cold-starts, holding ~124ms average auth latency.
Go · AWS Cognito · LambdaAWS infrastructure management (private)
Cut monthly infra cost 45% via ARM64/Graviton + Spot migration; hardened access with SSM Session Manager and IMDSv2; IaC with Terraform and CloudFormation.
AWS · Terraform · CloudFormationSSUnnounce
Serverless notifier that scrapes Soongsil University notices and emails category subscribers; a rewrite from headless-Chrome scraping to a direct API cut run time from 44s to 3s.
Go · AWS Lambda · DynamoDBRAG agent system
Production RAG pipeline for Korean legal multiple-choice questions (KMMLU); prompt and context optimization lifted dev-set accuracy from 51.6% to 53.7%.
Python · FastAPI · ChromaDBStudent council homepage backend (private)
Backend for the Soongsil student-council homepage — members, boards, notices, and auth — on Spring Boot with JPA, QueryDSL, MariaDB, and Redis.
Java · Spring Boot · MariaDBOpen source
Cadence #7585#7650#7709#7827#8035
Distributed workflow orchestration engine. Refactored the custom rate limiter, added dynamic configuration and context timeouts, and removed synchronous retry logic.
System-level AI model router. Deprecated legacy cache options and added file-based cache configuration.
A programming language. Added HTTP status code constants and fixed a bug in the "using" keyword.
Skills
Writing
What does the kernel do when a container exceeds a memory limit? 2026-07-15 Why the container runtime validates file's inode when opening a terminal? 2026-06-22 Optimizing CI/CD Duration with Self-Hosted Runners in GitHub Actions 2026-04-27 RAG System Implementation 2026-03-30 Observability Improvement Plan with Opentelemetry and Elastic Common Schema 2026-03-14 all posts →