9 min
Reading Existing Ghostty Tabs from TTYbird
AX findings and a verified UUID-directed Ghostty output snapshot.
Read moreghosttyttybirdrustaccessibilityterminal
Blog
Technical articles, software engineering, and daily learnings
12 min
Why the Latest Codex ISUCON14 Run Trailed the Historical Claude Record
The score gap is real, but hardware, durability, missing optimized application source, and different optimization paths prevent a fair model ranking.
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25 min
Astra Solo vs. Astra + GPT-5.6 Sol: Two Three-Hour ISUCON11 Studies
A controlled Codex SDK rerun narrowed the post-reboot gap to 2.3%, while Astra solo still recorded the higher peak with fewer tokens.
Read moreisuconcodexai-agentsperformanceaws
7 min
vda5050-lab — Evidence-Bound Diagnostics for VDA 5050 Temporal Failures
vda5050-lab addresses reconnect and state-transition failures that single-message validation cannot evaluate. This article explains its INCONCLUSIVE evidence model and the isolated 1, 2, 5, 10, 50, and 100-robot MQTT validation suite.
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8 min
isutools Dev Diary — Building an ISUCON Profiler in a Day with Claude Code and Codex
A development diary of isutools, an ISUCON profiler built in one day. It started as a teammate's everyday SQL logger; lacking the skill and time to extend it by hand, I leaned on Claude Code and Codex, with a design-doc-first, TDD, dogfooding workflow. Includes the honest open questions: am I actually learning, and will any of this matter in a real contest?
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4 min
isutools — a One-Line All-in-One Profiler for ISUCON
ISUCON measurement usually means juggling alp, pt-query-digest, pprof, and top. isutools is a Go OSS that collects SQL, HTTP, nginx logs, per-process CPU, DB schema, and pprof into one dashboard with a single sqlx.Open rewrite. Overhead measured at -0.58% (within noise). Setup and full feature tour.
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5 min
6th in the Combined Track at League of Robot Runners 2026, as a Team of One
As the sole member of Rovnou, I received the Top 10 Award (6th Place) in the Combined Track of League of Robot Runners 2026. Notes on lifelong MAPF, the planner stack, and the gap to first place.
Read moreroboticsmapfalgorithmcompetitioncpp
8 min
Breaking 500k on private-isu in One Day with isutools
A full log of tuning private-isu (Go) from a score of 0 to 541,650 in a single day. Every fix was driven by isutools, an open-source profiling module I built along the way — indexes, N+1 elimination, nginx tuning, caching, and pre-rendering, step by step.
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7 min
What Project Hail Mary Does Best
Project Hail Mary is very good at one of the hardest things in science fiction: making an unknown lifeform feel genuinely new. The best thing in the novel, to me, is not the ending, and not even the friendship at its center. It is the discovery of Astrophage.
Read moreBookProject Hail MaryMovie
14 min
What to Think About Before Measuring Landing Page Conversions
Practical lessons from rewriting a KPI definition document 5 times. Start with KGI, write hypotheses first, avoid the bounce rate trap, and speak business impact in dollars.
Read moreanalyticskpiab-testingga4conversion