Hi. I'm Haruyoshi Hattori, founder of coiai, in my first year running the company. coiai is an IT company that builds systems and products with technology at the core. Every Monday, I use this show to share what running a startup is really like.
Starting this week, I've renamed the podcast. It's now something like "coiai's Founding Log — an Engineer-CEO's Monday Broadcast." I wanted to make it clearer what the show is, and give it a more forward-looking feel, so I changed the name. Thanks for continuing to listen.
This week I want to talk about gadgets and tools, cutting infrastructure costs, and the personal knowledge-management repository I've been building lately. It overlaps quite a bit with the idea of an internal company wiki, so I hope you'll stick around for it.
Microsoft PowerToys is ridiculously useful
First up — something I started using this week that turned out to be great: Microsoft PowerToys. This might be old news to some of you, but it's a piece of software that fills in a lot of the gaps in Windows. It's developed officially by Microsoft, and it can do a bunch of things.
I use Windows sometimes and there have been plenty of moments where it felt inconvenient. That's because I normally use a Mac, so when I switch over to Windows, I notice all the little things it's missing. But for work, sometimes I have no choice — like when a Unity project needs to be launched from Windows specifically.
That's when installing PowerToys makes a huge difference — it brings a lot of Mac-like behavior to Windows, and honestly it impressed me enough that I wanted to share it with all of you.
Preview with the spacebar
First, you know how sometimes you open File Explorer and want to quickly preview an image at a larger size? Normally you'd have to double-click it every time. With PowerToys, you just hit the spacebar and it pops up in a preview mode. On Mac, this is standard — you press the spacebar over an image in Finder and it zooms up instantly. PowerToys brings that exact feature to Windows.
Automatic light/dark mode switching
Also, you know how there's light mode and dark mode — where your browser goes from white to black? On Mac, it switches automatically based on the time of day, but Windows doesn't have that built in. PowerToys adds that capability.
OCR text copy
Another one that really got me excited: there's a feature where you select an area of the screen with a shortcut, and it OCRs whatever text is in that region so you can copy it as regular text. So text embedded in an image can be turned into actual copyable, pasteable text data. It has this AI-powered feel to it, and it's genuinely strong.
Color picker
I used to rely on a third-party plugin on Windows for this, but I stopped needing it once PowerToys added its own color picker. Press Win+Shift+C and you can grab the RGB value or color data from anywhere on screen. It's incredibly handy when comparing design files during frontend implementation, so I use it constantly.
The launcher (PowerToys Run)
Then there's the equivalent of Spotlight on Mac — or Alfred, from a while back. I used to use Alfred myself, but I've mostly stopped since Spotlight got better. Well, Microsoft's PowerToys has its own version of this too. Press Alt+Space, or Ctrl+Alt+Windows+Space, and a launcher pops up. It's really powerful — app search, quick calculations, a built-in calculator — genuinely convenient.
The appeal of official, first-party tools
Basically, all those little annoyances you feel using Windows — the "Mac could do this" moments — PowerToys fills most of them in. And on top of that, it's free, which is great, and you can just download it from the Microsoft Store.
I have a real fondness for first-party, official tools. What I mean is, every OS has its own design philosophy baked into its UI. These days even Windows has rounded corners, but back in the day, macOS windows always had rounded corners while Windows windows had sharp right-angle corners. And these days there's Liquid Glass — macOS has its Liquid Glass look, and Windows has something more like glassmorphism going on. There was a period where Windows leaned into that glass-panel look — Outlook had that aesthetic for a while too.
What's nice is that with an official app, you get a consistent, unified Windows-specific Microsoft UI. Using an app that reflects the platform's own design philosophy feels great. Before, if you wanted everything PowerToys does, you'd have had to hunt down a separate app for each individual feature — the fact that it's all bundled into one official app is fantastic. It really feels like Windows has gotten stronger. Since it's free, I genuinely want to evangelize this to everyone — I really want people to use it, which is why I brought it up right at the top of the episode. If you're already using it, leave a comment saying so — it'll make me realize how out of the loop I was.
Cutting AWS costs for our Ochoko service
Next, a small thing I did at work this week. We run a service called "Ochoko." What it does is scrape sake data from around the internet and register it in an Android and iOS app, where you can log comments like "I tried this one."
To be brutally honest, it was costing us about ¥20,000 a month in AWS usage. That's pretty bad, right? You'd wonder why it costs that much — well, some AWS services bill you based on usage, and others bill you based on how long they run.
For example, with a service like Lambda or S3, you're billed based on how many times a function runs, or how much data is stored and how many requests come in for S3 — for small-scale personal projects, that usually comes out to just a few thousand yen a month. But I was also using RDS. RDS is a managed database service, and it charges you for however long it's running, so a full month of uptime is going to cost you at least ¥3,000 no matter what.
On top of that, I'd also made a configuration mistake — one of my resources was set to the US East region. I switched that over to Asia Pacific, Tokyo (ap-northeast). Fixing that small mistake helped, but the bigger move was switching the flat-rate RDS setup over to a service called Neon. That's the one piece I moved off AWS entirely, onto an external service.
What's great about Neon is that it's a serverless PostgreSQL service — you're not billed at all when it's not in use. You only pay for the access that actually happens, and the free tier is pretty generous. Since Ochoko's traffic is well within that free range, I switched over to Neon entirely.
You might think database migration would be a huge hassle, but it turned out to be surprisingly easy, mostly thanks to AI. I leaned heavily on Claude Code for this, and Claude was excellent. Both AWS and GCP can basically be operated entirely through the command line these days, which means you're dealing with text — and that plays very well with LLMs. So the migration and deployment went smoothly, and I was able to move everything over to Neon with ease. The AWS bill that used to run about ¥20,000 a month should land somewhere between ¥300 and ¥6,000 this month. It worked out great.
Knowledge management with Obsidian × Git (also applicable as an internal wiki)
Next topic — this one's more like an internal company wiki story.
This started about a year ago, inspired by an article from someone named Kyohei about "managing my own life through a GitHub repository." On top of that, I'm a big fan of Obsidian. Obsidian isn't so much an app for taking notes in Markdown files as it is an app that makes Markdown files pleasant to read.
Organizing files with the PARA method × GTD
So first, I thoroughly organized my files in Obsidian. There are all kinds of ways to organize files — I actually wrote about this on my blog recently, so check out coiai.net if you're interested. I use a method called PARA, along with ideas from a book I read a while back called "Getting Things Done." That book is about not wasting your brain's limited resources on holding onto information — just write it all down — along with a bunch of similar tricks. I read it a good while ago, maybe five years back.
I'd read about that method, and there are apps like OmniFocus built around it, but they're pretty expensive — something like ¥10,000 a year — so I figured it was too much of a hassle to commit to on my own and let it go. But since I was already organizing my files and notes, I figured I'd mix the GTD approach with the PARA method and build my own personal project-management system.
Directory structure
Let me walk you through the directory structure — I want you to hear about my ultimate file organization setup.
00_Inbox— a holding place for things you're not sure where to file yet. When in doubt, just toss it in here.01_Projects— projects currently in progress. Things like podcast scripts or current client work.02_Areas— ongoing areas of responsibility, like health or finances, that need continuous upkeep.03_Resources— interesting technical articles, reference material, and anything related to hobbies. I'm into cigars, movies, and furniture, so I'll save furniture or watches I liked here. I love clothing too, so if I come across a detail I love — like the cut of 1920s riding breeches — I'll save that here too. I'm also into spice curry, so recipes for spice curry go straight in here too.04_Archives— tasks that are already completed.05_GTD— based on Getting Things Done, this holds next actions, "Waiting For" items (projects pending someone else's reply), and "Someday/Maybe" items (things I want to do eventually).
This might work even better as a kanban setup — I haven't tried it yet, but Obsidian has a kanban plugin, so I think that could take this to the next level.
A script that automatically collects news
Here's something I want you to hear about — I built a Python file called collect_news.py that, when run, pulls the top ten stories of the day each from Hacker News and Zenn. Running it fills up a folder called 06_DailyNews with the day's news.
This has been great. What used to mean opening Zenn or Hacker News individually and gathering articles by hand now happens just by running one Python script. That's been a real game-changer. I picked this idea up from a YouTube video by the same Kyohei I mentioned earlier — I watched it, thought it looked great, and gave it a try myself.
Multi-device sync with Git × GitSync
So basically, I manage everything related to my life — as notes — through Git, and I open and view that Git-managed content through Obsidian.
I also want to view this Git-managed content on Android and iPhone, as notes on the go. So of course I use Obsidian's Git plugin, but there's also an app called GitSync — I think it's developed by someone in China, though I'm not totally sure — that lets you clone a Git repository on Android, with full pull and push support. It's free, and I use it to view my "LIFE" repository from Obsidian on my Android phone too. It's incredibly convenient.
Essentially, without using Dropbox, iCloud, or any paid Obsidian plan, I've got completely free version control and sync across multiple devices.
It's really comfortable, and if it keeps working well, I think this setup could become our internal company wiki too. Google Drive is nice, sure, but being a web service, you have to click through every single folder level one at a time, which gets tedious. Obsidian lets you flip through folders quickly, almost like an accordion menu, and that's fantastic.
One thing I'm careful about is not letting the folder hierarchy get too deep. I try to keep as many files as possible at a shallow level, so that anyone looking at it can understand it without confusion. That's part of why I think this could eventually work well as an internal wiki too.
A ToDo-driven development style
One more development-related thing before I wrap up.
Lately, I've been managing my work with ToDo lists during development. The reason is that when you're developing alongside AI, you start forgetting exactly where you left off. If you keep asking the AI "wait, what was I doing next?" every time, it burns tokens, and if the AI has to look back through the history, there's a risk of hallucination too — it's just wasteful.
So now I have the AI create a docs directory in the project up front, with a ToDo list inside it — specifically for things I need to do myself. Since AI is fundamentally an LLM, it's only really good at manipulating language — it's still not great at operating interfaces directly. There's a fair amount that I have to do myself, so I just tell it, "make me a checklist for that part," and it builds the checklist.
In Markdown, you can make a checklist with - [ ]. This turns out to be really convenient — when I open the file in Obsidian, it renders as an actual checkbox that I can tick off. That's been extremely useful.
And it's not some vague grouping like "today I'll do sales work, then dev work, then take apart a camera" — I make the ToDos absurdly granular. For something like an in-app purchase — say, for Meta Quest — it'll be broken down into "open the Quest developer console," "open the add-content tab," "add the content," "enter a title and price for the content," and so on, with checkboxes for each tiny step. That completely eliminates the "wait, what do I do next" moment, and it basically automates me. So this has been really useful.
It's great for tasks that don't quite need a full week of tracking via Git commit logs, but are too much to hold in your head alone — give it a try.
This week's tech-news thoughts
That wraps up the tech news for this week. Looking back over the week's coverage, there really was a lot of news around how to use Claude Code. There was also a tool called Jujutsu that's meant to make Git easier to use, but honestly, if you're already comfortable with Git, I don't think you need it that much. I generally prefer keeping things simple and don't love loading up on plugins, so in the interest of keeping things simple, I'm going to pass on Jujutsu for now. That's roughly the state of this week's topics.
Small talk
Trying anglerfish hot pot for the first time
The supermarket had anglerfish for sale recently — around 500 yen, maybe even cheaper — so I made anglerfish hot pot, and it was my first time eating it. Have any of you had anglerfish hot pot? If you have, I'd love to hear your thoughts on the taste in the comments.
I'd assumed anglerfish would be something like a white fish, but it turned out to be pretty firm — not soft and flaky at all, more chewy and springy. It caught me off guard — honestly, it reminded me more of offal. You turn the liver into a paste and make a soup with miso, and that part was quite good, but the anglerfish meat itself had me wondering, "is this actually good?"
I think there are two categories of expensive food. One is stuff that's expensive because it's rich or simply popular — sirloin steak, fatty tuna — things that are both delicious and popular, hence pricey. The other is stuff that's expensive because it's rare, regardless of whether it's actually tasty — ostrich meat, for example, is expensive purely because it's uncommon.
There's this place in Takadanobaba called Kome to Circus, kind of an exotic-food restaurant, where I've eaten ostrich and bear meat — both were quite pricey. But you'd wonder, "is this actually good?" I think anglerfish leans toward that category too, though I feel a little bad saying that about it. It was such a striking flavor that I'm genuinely glad I tried it.
And honestly, if some wealthy person told me "oh, I love anglerfish," I'd think, this person isn't new money. Saying you love sirloin steak, or fatty tuna, or sea urchin — those are all obviously delicious flavors. But anglerfish has a deeper, more subtle appeal, so anyone who genuinely likes it probably isn't just flaunting wealth — they probably really do love it. Not sure where I'm getting that bias from, but there it is.
Men's makeup with BB cream
Also, I recently bought BB cream again — the men's version from Canmake. I've been getting some dark spots lately, so I started applying it, and nobody's noticed at all. Nobody noticing is actually a good thing, in my opinion — if it were obvious you were wearing men's makeup, that would feel a little embarrassing. Not that there's anything wrong with it, to be clear, but still.
So it's a pure self-confidence boost with none of the downside, and I really like that about BB cream. It also protects against UV rays, so it's good for your skin too. I'd recommend everyone try men's makeup — even if it's just BB cream.
Ending
All right, that about wraps up this week. coiai works on web development, XR development, core systems, and on-premise AI (bringing AI into local environments). We can take on pretty much anything, so if you've been turned down elsewhere or gotten a quote that felt too high, feel free to reach out — quotes are free.
See you again next Monday — subscribe to the channel and I hope you'll come listen again next week. Thank you.