Joohyung Park
Programmer
Currently
Located in Yong-in, South Korea. Working on founding an exciting project
Specialized in
- Algebraic Effect Handler
- Railway oriented programming / Domain driven development
- Backend services with GraphQL
- Complex domain (HIRA rule) modeling
- Cloud native applications on Kubernetes
- Optimizing for the trade-offs among availability, consistency, and query power
- Multitiered metadata / data management
- Performance optimization exploiting tracing techniques
- System overload protection by circuit breaking
Occupation
Feb 2024 - Now
__on_the_ground__
Founder
Feb 2021 - Jan 2024
Healthcare, Medibloc
Software Engineer
Sep 2016 - Jan 2021
Storage Platform, Platform Labs, Naver
Software Engineer
May 2011 - Feb 2013
The 5th Signal Group, Republic of Korea Defense Communication Command, Republic of Korea Armed Forces, Ministry of National Defense
Sergeant
Projects
- Ohwl: Finance modeling (Python)
- Dr.palette: Cloud-based EMR (Typescript)
- Nubes: Multitiered Heterogeneous Distributed Storages (Go)
- DDZ on eBPF: User-defined IO Tracing on eBPF (Go / C)
- Strbench: Random Load Generator / Benchmark Tool for Generic Storages (Go)
Publications / Presentations
- 가제: TypeScript/Kotlin으로 작성하는 도메인 주도 설계와 함수형 프로그래밍, Jpub 2025
- Domain Modeling Made Functional: Tackle Software Complexity with Domain-Driven Design and F#, Medibloc in-house presentation 2021
- Nubes on NCC: Lessons Learnt from The Migration of An MSA Storage Service onto K8S, Live Session, Naver Engineering Day 2020
- 네이버에서 분산플랫폼 개발자로 일한다는 것, Live Session, Naver Open Class 2019
- DDZTrace: An Online Semantic-aware Block Tracing Tool, Poster Presentation, FAST 2016
Technical Skills
- Languages
- Go, Typescript, Python, Kotlin, Ruby, C, Bash
- Architecture / Paradigm
- Algebraic effect
- Hexagonal architecture
- Event-driven architecture
- Railway oriented programming
- Domain driven development
- Framework
- Dapr
- NestJS, TypeORM, ReactiveX
- Hotrails
- API technology
- Hosting Environments
- Cloud native
- Linux kernel
- I/O stack: vfs, mm, block, driver
- CPU scheduler: cfs
- Resource management: cgroup
- System Tracing / Profiling
- Data sources: kprobe, tracepoint, uprobe, usdt
- Data extraction: eBPF, ftrace, perf
- Frontends: eBPF, trace-cmd, ftrace, perf
- MSA Components
- Databases: PostgreSQL, MongoDB, Redis, RocksDB
- Message Queue: Kafka
- Coordinator: Dapr on K8S, Consul
- Hardware side
- SSD internals(FTL, inter / intra architecture of SSD)
Education
Sep 2014 - Aug 2016
M.S., in Department of Electrical and Computer Engineering, Sungkyunkwan University, Republic of Korea [Advisor: Prof. Jin-Soo Kim]
Mar 2007 - Sep 2014
B.S., in Department of Semiconductor System Engineering, Sungkyunkwan University, Republic of Korea