Myeonsoo Kim — Backend Engineer
I am Myeonsoo Kim (김면수), a backend engineer who narrows production problems through code and measurement, then publishes the decisions as records other engineers can verify.
The principle of this blog is: engineering is the explanation of choices. Instead of restating generic tutorials, I document:
- assumptions that turned out to be wrong,
- counterexamples that broke an implementation or specification,
- rejected alternatives and their trade-offs,
- reproducible test and measurement environments,
- the real PRs, issues, commits, and source code,
- and the boundary of what the evidence does not prove.
Current focus
- safe selection and leasing of reputation-bearing proxies, accounts, and sessions,
- Java concurrency contracts and linearizability testing,
- the boundary between a JDK-only core and a SaaS host,
- multi-tenant isolation, noisy-neighbor control, and horizontal scaling,
- and operational reliability for scraping systems.
Public projects
- PreAgile/reputation-pool — a JDK-only reputation decision and resource-leasing engine
- PreAgile/reputation-pool-cloud — a hosted SaaS built on the public engine
- Building reputation-pool — the connected series of implementation failures and redesigns
How to evaluate these articles
Each deep dive includes the tested version, environment, PR, failure trace, and limitations whenever the evidence exists. When production data is not available yet, I say not measured yet instead of presenting a hypothesis as a number.