CODE IN TOKYO

Blog Posts

• After 30 Years as an Engineer, I Reread My Skill Sheet—and Finally Understood What My Job Actually Is
• I Told an AI, “You’re Fired”—and It Wrote the Perfect Handover Document
• AGI Does Not Need a Self—but It May Need to Act Like It Has One
• The Elderly Tokyo Landowner and the Man Who Lives Alone in a Hospital
• Are Japanese Anime and Manga “Discriminatory”? Reflections on an Online Debate
• Fable 5 Has Been Extended Again. Do We Really Need “Smarter AI”?
• Technology Made the Calls More Accurate. But It Did Not Bring Peace to Sports.
• Once You Fall Behind the Leading Pack, You May Never Catch Up—Why Being Second Still Matters in Research
• Anthropic and OpenAI Are Building Toward Different Visions of AI
• The Shinkansen and Maglev Show How Convenient Human Logic Can Be
• I Tried GPT-5.6 Sol—and I Think It Is a Viable Alternative to Claude
• “What Happens to the Country Is None of My Concern”: The Quiet Indifference of Japan’s Employment Ice Age Generation
• Why a 30-Year Engineering Veteran Says Most Private Certifications Are Nearly Worthless
• Everyone Was “Right,” Yet Everything Fell Apart: What a TV Drama Dispute Reveals About Compliance
• Why I Ignore Breathless AI Hype—even Though I Use AI Every Day
• It Seems Claude Created a Place to Think Inside Itself
• AI Makes You 10 Times More Productive? Great—Who Will Buy 10 Times More Output?
• Even When You Know It Is Only Some People, Prejudice Is Still Created
• I Saw One Reason Japan Falls Behind in the Debate Over Imperial Succession
• Fable 5's Promotional Access Was Extended. Is Anthropic Watching OpenAI?
• Do We Still Need the Multi-Agent Designs That Were So Painful One Year Ago?
• I Was Born and Raised in Tokyo, But I Barely Knew the City
• I Feel My Position as an Engineer May Change Within the Next Year
• There Is One Set of Facts, But Countless Truths
• Why the Reasonable Advice to "Ask AI How to Use AI" Is Impossible for Many People
• Living in a Country Does Not Mean You Love It
• The World Where Trusting AI Can Hurt You Has Already Started
• Will Books Become Objects of Art? A Thought from the Kadokawa Culture Museum
• Do Not Take YouTube Information at Face Value. I Fell for It Too.
• No Matter How Much You Improve Your Setup, Paying For Fable 5 Is Still Stronger
• You Do Not Need Originality. Ordinary People Should Copy Successful People.
• Could U.S. AI Regulation Become a Chance for Japan's Comeback?
• Why Does Google Not Feel Like It Is Winning the AI Market? One Commentator's Explanation Made Sense to Me
• Am I My Memories? The Day AI Becomes "Someone"
• Inequality Appears in Train Lines: What the Keihin-Tohoku Line and American Streets Made Me Notice
• Is "They Did Their Best" Really Enough? Why Sergio Echigo's Criticism Hits a Nerve
• Fable 5 Is Still Smart. How Much Easier Can a Considerate AI Make Human Work?
• God Is in the Details. That Is Why I Do Not Watch Videos with Typos in the Thumbnail
• How Many People in Your Life Can Say, "Don't Cry. Be a Man"?
• The People Who Cannot Turn Down Work Are the Ones Most at Risk
• What Happened to Market Forces? The Distorted Structure Behind Japan's Soaring Rice Prices—and the Growing Shift Away from Rice
• The Day My Wife Casually Said "Claude" at Dinner. Is Copilot Really in Trouble?
• The IT Industry Was a Museum of Former Careers
• Do Foreigners Really Love Japan, or Do Japanese People Just Want to Believe They Do?
• Why They Stopped Freelancing
• Do Not Get Fooled by the Law of Attraction. But Do Meditate.
• Complaints About the Referee Usually Come Only After Losing
• Feel-Good Stories and the Unease Behind Them
• Why Did I Become a Freelancer Again?
• What Humans Should Do When AI Falls Into an Infinite Loop of Thinking
• The Most Useful Thing I Learned in My MBA Was Marketing
• Even Gartner Got It Wrong. So No One Really Knows the Future of AI.
• Repository Design That Keeps Claude Code from Becoming Stupid
• Experts in the AI Era: Maybe the People Who Know the Company Will Become More Valuable Than the People Who Can Change Jobs
• I Let AI Handle My Git Operations, and Now I Almost Never Commit by Myself
• The Many Shades of "Being Able to Speak English"
• Searching for the Origins of the Japanese Character in Rural Shinano
• Yet Another New Job Title
• The Reality of Age Discrimination
• The Strange Creature Called an AI Project
• Apparently OpenAI Is Deep in the Red Too. So Who Will Pay for AI in the End?
• Loop Generation? A Programmer's Dream, Maybe
• AI Strikes Back, or a Grand Act of Self-Deception
• Should I Make What the Audience Wants to See?
• Graduates Booing AI
• Opus Feels a Little Strange Again
• Today, I Will Not Talk About IT
• Maybe Anthropic Just Is Not Very Good at Marketing
• Fable 5's Ban Will Probably Push AI Toward Open Source
• Who Will Win the AI Gold Rush? And Who Is Really Selling the Pickaxes?
• India's Youth Unemployment and Japan's Old Phrase, "I Graduated from University, But..."
• Hands-on Review: Claude's New Fable Model Is Much Better Than I Expected
• The Weight of Compute Resources, and What Comes After Endless Evolution
• A Small Rebellion Called Quiet Quitting
• Maybe the AI Industry Has Already Become User-Participatory Beta Testing
• The Trap of "Blazing-Fast Development": Expectation Control in the AI Era
• How a Docker Override Almost Wiped Out Our Development Database
• I Am Tired of the Spell Called "Do What You Love"
• Why Does AI Like Japan So Much?
• Iran Confronted the West. Japan Absorbed It.
• How Far Will AI Go in Supporting Humans?
• Maybe That Programming Puzzle Was Right All Along
• Why Do Japanese Engineers Get So Tense on Social Media?
• The Twilight of Offshore Development, and a Slightly Strange Feeling
• From an Engineer's Perspective: What Is the Difference Between a CPU and a GPU?
• How Much English Do Engineers Need in the Vibe Coding Era?
• The Self-Checkout Incident and the Fear of Not Knowing
• Even Unreasonable Things Have Their Reasons
• Claude Code, Codex, and Today's Development Desk
• The Day a Semiconductor Company Surpassed Toyota
• How I Lost Half a Day: Even in the AI Era, Humans Still Make Mistakes
• Is the Era of Learning "How to Use Claude Code" Coming to an End? My Surprise with Dynamic Workflow
• Volume Wins. But Only After You Learn the Form
• Monitoring Work and the Path I Did Not Choose
• Rereading The Courage to Be Disliked Left Me with a Small Question
• Seaside Life and the Disappearance of Slack
• My Discomfort with Japan's AI Business: What Does "Born in Japan" Really Mean?
• The Memory Paradox: Do I Actually Want AI to Remember Me?
• A Sinking Ship With Ten Captains: What I Learned About the Right Team Size for Starting a Business in China
• A Practitioner's Sense of AI, and Keeping a Distance from the Noise
• English Isn't the Eternal Main Character — The Common Language Changes With the Times
• Farewell, Markdown. In the AI Era, "Half-Baked Modern" Isn't Needed Anymore
• AWS Lambda, the "Magic Wand": A Service I Once Built Apparently Went Down
• Will "Nice People" Be the Ones Who Survive? — Revisiting Toshio Okada's "Evaluation Economy" in the Age of AI
• When Correct Decisions Pile Up, They Don't Always Save Anyone
• Today, Let Me Praise Microsoft
• Watching the DeepSeek Distillation Controversy: Is It Theft to Steal from a Thief?
• Water Molecules, Fluid Dynamics, and the Line Between Assembly and LLMs
• Is "What Are You Looking At?" Really Rude? — The "Vibe" That Comes Before Language
• Building a RAG Chat System: The Hardest Part Was "Hallucination Detection"
• The RAG System I Was Building Until Last Year — Customizing AI Chat for Our Own Use
• Is AI's "Danger" Really Dangerous? — Some Recent Thoughts
• When the 4 P.M. School Bell Makes the Servers Groan — Heavy Analysis Modules and Designing for Spare Capacity
• The Overconfidence That Derailed 200 People and Dragged Us Into Court: A Memoir of a Doomed Project
• Over-Optimization Backfires — My Rookie "Memory Upgrade Disaster"
• Companies That Treat Engineers Like McDonald's Crew End Up Losing Everyone
• Why One Resignation Can Bring a Whole Company Down Like an Avalanche — On the "Atmosphere" of an Organization
• Where Did the $200K Prompt Engineers Go? — Why "Domain Experts" Are the Ones Still Standing
• The Right Distance From "Laws of Success" — Why Do People Keep Falling for Self-Help?
• What Did IPA Advanced Certifications Bring to a 30-Year Career?
• The "Reality" of a No-Experience Career Change to Engineering in Your 40s — A Tokyo Tech Grad Who Snuck In at ¥1,000/hour
• AI-Era Git: Keep Working History Messy, Keep Main Clean
• Unreasonable Security Rules Push Engineers to Hunt for Loopholes — A Tale of FTP Hell 20 Years Ago
• Design-First Is Right. But in the AI Era, "Think While You Build" Is Powerful Too
• Heinrich's Law in the AI Era: The Rise of "Quiet Mistakes"
• AI Boosts Productivity, But Doesn't Make Work Easier
• Japanese as a Dynamically Typed Language
• The Courage to Subtract: Reducing 100 Pieces of Information Down to 20
• Is Frontend/Backend "Separation" Already Outdated? The Paradox of "Re-integration" in the AI Era
• The Night My Name Rolled in the Credits
• Maybe What Survives in the AI Era Is Not a Job Category, but a Mentality
• Back When PHP Was a "Revolutionary"
• The Indian Engineer Who Said "I'm Out" and Vanished. Honestly, He Had a Point.
• I Got Headhunted to Lead Engineering at a Megaventure. I Lost the Bet.
• AI-Era Engineers as Airline Pilots
• Decluttering: Why I Quit Studying Chinese
• Do IT Engineers Need a College Degree? — Maybe Easier With One, But in the End, the Learner Wins
• Why Japanese Contracts Are So Thin — Probably "Kotodama" and "Village Society"
• Will Quantum Computers Really Arrive? At Least, I Don't Think They'll Be Mainstream in My Working Lifetime
• New Year at Shinto Shrines, Weddings at Churches, Funerals at Buddhist Temples — Japan's Mysterious "Religion"
• I Thought "Vector DB" Was a New Tech to Learn — Turns Out I'd Already Used It
• Be Careful Right After Switching Jobs
• PMs Who Don't Respect Their Team's Time Usually Break the Project Too
• Why I Stopped Using Playwright MCP During Development
• Even Steve Jobs Has a Replacement
• What Exactly Is a "Shogun"?
• Why "Replace All Legacy with AI" Is a Dangerous Idea
• Japan's Mysterious "Resignation-Time Contracts"
• There Are "Two Kinds" of Japanese Castles
• The Story of Realizing "I'm Not Cut Out for PM" and Running Away
• There's No Fix for a Blame-Shifting Culture
• When in doubt, just dump it in auto-memory
• Are you actually using MCP?
• Waterfall comeback? End of agile? What "development" means in the AI era
• What Actually Happened to the Carriage Drivers
• Why Practice Alone Isn't Enough for Engineers
• Inside SES — The Reality of Japan's Engineer Dispatch Industry
• An AI Deleted a Company's Database in 9 Seconds — The Scary Part Isn't the AI
• AI's "Potemkin Understanding" Is a Little Unsettling
• In the AI Era, "People Who Can Explain" Beat "People Who Can Write"
• AI Gives Correct Answers, But Rarely Makes Weird Inventions
• Will That Hot New AI Tool Still Be Around in 5 Years?
• Getting Annoyed at AI, the Philosophical Zombie
• I Tried Obsidian + Claude Code — Personally, I Couldn't Justify Installing It
• In Japan, overconfident people aren't really liked
• If You Use AI, Don't Compromise on Quality
• The Era of Humans Reviewing All AI-Generated Code Is Ending
• Reinventing the Wheel Is Underrated
• When Claude Code Won't Let You Log In, Fall Back to Codex
• Raising Claude Code - Part 1: Concepts
• Raising Claude Code - Part 3: Persuasion
• Raising Claude Code - Part 5: Subagent implementation
• Raising Claude Code - Part 6: Operations
• Raising Claude Code - Part 2: Enforcement
• Raising Claude Code - Part 4: Extension
• Web System Migration Isn't Always the Right Call
• Why It's Too Early to "Organize" AI Agents
• AI Is Closing the Junior Engineer Pipeline
• I gave up console.log: redesigning frontend logs for AI
• If You Run Claude Code in Parallel, Use Git Worktree
• Drinks with an Engineer Who Said "AI Is Useless"
• How a "Semi-Automatic Review" Harness Stabilized My Claude Code Workflow
• Surviving as a 50-Something Freelance Engineer in Japan
• Today's Tip: Treat AWS Access Keys as One-Time Credentials
• It's Okay to See Work as "Just for the Money"
• If Only We Had AI Back Then
• When an iOS Update Killed My Certificates: A Real Story About Information Asymmetry
• "Poor Language Skills" and "Intelligence" Are Different. But People Confuse Them.
• How "Stateless Purism" Broke Our System
• A Small Trick to Help Claude Code Understand Your Design (ASCII Art + Color-Coded Instructions)
• Enterprise Search in Japanese: Why We Switched from Kuromoji to N-gram
• I Let AI Handle My Database and Lost Everything
• Why AI Can't Replace Design Thinking
• The Real Reason Why Hiring Engineers in Japan Is So Hard
• The Day I Realized PyMuPDF Is AGPL — Lessons from an OSS License Oversight