Podcast

A Conversation with Mathematics Researcher 橋本勇 on the "Disjoint Covering System"

coiai founder 服部陽良 sits down with mathematics researcher 橋本勇 to talk about his newly submitted paper on the Disjoint Covering System, along with this week's AI news, including OpenAI's GPT-5.6.

#21 | How to Start a Podcast the Lazy Way

coiai founder 服部陽良 breaks down his entire one-person podcast workflow — gear, script writing, editing, and distribution — plus this week's news on AI-era contract development and an iOS privacy app called Loupe.

#20 | Trying Out Fable 5, and a Design Theory of "Structure vs. Decoration"

coiai founder 服部陽良 tries out Anthropic's new "Fable 5" model, then unpacks a design theory about why structure gets copied unnoticed while decoration always gets caught — with detours into supply and demand, underpricing work, and what manual transmissions teach us about UI.

What Anthropic's Report and Ferrari's First EV, the "Luce," Reveal About Design

coiai founder 服部陽良 reacts to Anthropic's "When AI Builds Itself" report on Claude writing over 80% of its own codebase, then turns to Ferrari's first fully electric car, the Luce, for an honest, opinionated look at industrial design.

18 | I Built a Company Because I Can't Survive Alone — On Belonging to a Pack, and Relying on Others

coiai founder 服部陽良 announces two open hiring roles, recounts a fun XR development retreat in Karuizawa, and shares a rough patch of getting sick with no days off — leading into thoughts on why humans need to live in packs.

#17 How We Turned 61 Business Cards from a Trade Show into Real Sales Conversations

coiai founder 服部陽良 walks through how he sorted 61 trade-show business cards into three tiers, built follow-up proposals with Claude Code, and used AI-assisted "vibe coding" to turn demo apps around in a single day.

#16 Everything I Learned From My First Time Exhibiting at a Trade Show

A full recap of coiai's first-ever trade show booth at Startup Japan Expo — from posters and flyers to the on-premises AI demo that stole the show, booth-calling scripts that actually worked, and the follow-up that turned 61 business cards into three sales meetings.

#15 Restructuring Our Design Guidelines for AI Completely Transformed Our Production Efficiency

coiai founder 服部陽良 traces design guidelines back to Paul Rand's work, then explains how rewriting coiai's own guidelines as a plain-text Markdown file, complete with explicit "don'ts," dramatically improved AI-generated design output. Also covers Google's Gemma 4 and the future of on-device LLMs.

#14 This Week's Tech News, and Wrestling with Our Company Mission Statement

This week's tech roundup covers Sora's shutdown, the ChatGPT-Cloudflare controversy, Voyager 1's 69KB of memory, and the backlash over Rakuten's "domestic" LLM, before 服部明 opens up about breaking big goals into small tasks and trying to give his company a real mission statement.

[Spoilers] Why "Chou Kaguya-hime" Was Incredibly Good

A special, fully spoiler-filled bonus episode where 服部 gushes about the anime "Chou Kaguya-hime" — its genius protagonist, its believable near-future SF world-building, and a twist where an AI and a soul that crossed 8,000 years become impossible to tell apart.

#13 The Danger of Systems Built with No Buffer

服部明 digs into whether a mission-vision-values framework is really as grounded as everyone claims, then argues that good system design has to leave room for human error, using a library book-return system as a cautionary example.

#12 The Struggles of an Engineer-CEO Who Can't Sell

Hattori runs through this week's tech news — typed languages doing better with Claude Code, the "AI slop" debate, and Anthropic's stance on military use of AI — before opening up about the hardest part of running a one-person engineering startup: sales.

#11 Getting AWS's Fixed Costs Close to Zero, and Managing My Life With Git

Hattori raves about Microsoft PowerToys filling in Windows' missing features, explains how switching from RDS to Neon shrank a roughly ¥20,000-a-month AWS bill down to almost nothing, and shares how he manages his entire life — notes, tasks, and news — through Obsidian and Git.

#10 entire and the AI Pyramid — Tech I Tried This Week

Hattori looks at entire, GitHub CEO Thomas Dohmke's idea for tying AI agent sessions to Git commits, then recounts a friend's uphill struggle getting Openclaw running locally on an AI Pyramid device.

#9 Filing Corporate Taxes and Closing the Books Without an Accountant

Hattori walks through how he closed his company's first fiscal year and filed corporate taxes entirely on his own, covering the accounting software he chose, the mountain of supporting schedules the filing required, and the quirks of Japan's e-Tax and eLTAX systems.

#8 Design Guidelines and Docs in the Age of Vibe Coding

Hattori tries Claude Opus 4.6, argues design guidelines belong in Markdown so AI agents can actually read them, and makes the case for a docs directory — including an AI-written development diary — as essential infrastructure for vibe coding.

#6 Three Things You Need to Start a Company & Why It's Time for Official First-Party Tech Stacks

The 26-year-old founder of coiai argues that AI is making cross-platform frameworks unnecessary in favor of native Kotlin and SwiftUI, shares three hard-won lessons about starting a company, and recounts a strange afternoon at his tailoring side gig.

#5 With AI, Development Shifts From "Writing" to "Defining" — This Week's AI Tool Report

Hattori shares how he splits coding work between Cursor and Claude by language, why pairing Marp with an LLM makes slide decks appear almost instantly, and how AI is shifting engineering's core joy from writing code to defining requirements.

#4 I Went to the Hans Wegner Exhibition! Let's Talk Furniture!

A summary of this episode's trip to a Hans Wegner exhibition, covering the designer's craftsman philosophy, his skepticism toward plastic furniture, his ties to Børge Mogensen and Arne Jacobsen, and why his chairs now sell for over a million yen.

#3 How New Year Stopped Feeling Special, and a Math Problem Nobody Else Is Working On

Hattori and Hashimoto talk about how New Year's stopped feeling special once it became just another workday, their mixed feelings about lucky-charm traditions like kumade rakes, and Hashimoto's unsolved number theory problem that maybe only three people in the world care about.

#2 What Does a Beautiful Proposal Document Format Even Look Like?

Hattori and Hashimoto wrestle with the split between presentation slides and printable proposal documents, detouring through typography's legibility-versus-readability distinction and the differing histories of paper and the web.

#1 How Do You Even Do Sales Right After Starting a Company?

In the debut episode of coiai's Strategy Meeting, three engineers with zero sales background talk through their struggles landing clients — from testing outsourced sales agencies to DMs, ads, and press releases they can run themselves.