I'm Johnny Kao.
This GitHub is a second Johnny — a space for open-source contributions, experiments, and ideas worth exploring.
My background spans finance, consulting, strategy, and cross-border systems. My interests also include research and publishing. I've never liked staying in just one lane.
I focus on performance, correctness, and concurrency in open-source infrastructure — finding unnecessary work, fixing subtle issues, and making small, maintainable improvements backed by evidence.
For detailed research, benchmarks, and contributions, see CoreFoundry Project.
Selected upstream contributions and performance research.
| Project | Optimization | Measured result |
|---|---|---|
| pandas #69916 | Removed redundant NA checks in numeric conversion | 16.5–24.7% less time |
| urllib3 #5304 | Avoided redundant gzip decompression copies | 14.7–39.2% faster |
| urllib3 #5287 | Optimized HTTP header processing | 9–13% faster |
| LZ4 #1858 | Skipped unnecessary zero-length writes; later integrated upstream | ~10–25% faster |
| idna #279 | Proposed an ASCII domain-label fast path; approach later adopted upstream | 79.5–85.1% less time (original candidate) |
| attrs #1636 | Optimized astuple() for nested atomic sequences |
Up to 3.33× faster |
| Memray #1035 | Reduced multithreaded allocation contention | Up to 28% lower runtime |
| c-blosc2 #805 | Eliminated unnecessary parallel overhead | Up to 17.8× faster |
| python-blosc2 #728 | Removed redundant memory zeroing | 2–15% faster |
Performance figures reflect specific benchmark workloads, not general production-wide speedups.
| Project | Improvement | Validation / outcome |
|---|---|---|
| NumPy #32802 | Eliminated signed-shift undefined behavior | UBSan verified · 48,592 tests passed |
| SciPy #26225 | Fixed iteration accounting for four root-finding solvers | 178 tests passed |
| QuickFIX/J #1363 | Prevented failed synchronous FIX writes from reporting success | Merged · 9/9 fork CI jobs passed |
| python-blosc2 #713 | Fixed two thread-safety bugs affecting free-threaded Python | Merged · concurrent stress validated |
- CVE-2026-115529 — Discovered and reported a curl Schannel TLS session-resumption vulnerability. CVE assigned, upstream fix committed, and officially credited.
🧭 Timeline Highlights
- 2026 — 📊 Deepened upstream OSS work across scientific Python, systems, networking, profiling, compression, and security research. Expanded independent publishing and established JQPP.
- 2025 — 🚀 Moved from consulting into startup finance and corporate development, supporting a multi-billion-JPY fundraising extension and board-level decisions.
- 2024 — 🧭 Worked across digital transformation, AI adoption, future banking strategy, and RWA tokenization.
- 2022–2023 — 🌐 Worked on institutional digital assets, wealth management, payments, and emerging financial infrastructure.
- 2020 — 🧊 Code preserved in GitHub's Arctic Code Vault.
- 2019 — 🏦 Worked on virtual banking and cross-border financial infrastructure.
- 2015–2018 — 💳 Built and worked around payments, Bitcoin-linked card infrastructure, fintech, SaaS, and digital-asset systems.
- 2013 — 🤝 Volunteered in Tunisia.