yjsoon

• Home-Cooked and Barefoot

  10 Oct 2025

  There’s this 2020 Robin Sloan essay on apps as home-cooked meals, which I cite endlessly to my students and anyone who’ll listen. It’s about how “an app can be a home-cooked meal”: When people learn to cook, most aren’t aiming to become professional chefs; they likely just want to make a meal for themselves, or the ones they love.

  The same goes, I tell my students when they deign to listen to me in between Subway Surfers scrolling sessions, for them learning to build apps.

  “You don’t have to become a software engineer! It’s great to just be able to build!”

  “OK! Skibidi.”

  Today, I came across this talk, “Home Cooked Apps and Barefoot Developers” by Maggie Appleton. It’s great:

  It’s also available on Appleton’s website in essay / slide transcript form (such lovely slides!).

  Appleton puts forward an updated thesis for this age of agentic coding. With AI coding becoming more and more capable… and, funnily enough, she gave this talk in 2024, pre Claude Code, pre “vibe coding”, in a stone-age world of just Copilot and Cursor… with AI coding becoming as powerful as it is nowadays, “large language models will create a golden age of local, home-cooked software and barefoot developers”:

  I have this dream for barefoot developers that is like the barefoot doctor. These people are deeply embedded in their communities, so they understand the needs and problems of the people around them. So they are perfectly placed to solve local problems. If given access to the right training and tools, they could provide the equivalent of basic healthcare, but instead, it’s basic software care.

  I love the idea of home-cooked apps. I’ve recently been making a couple of web apps purely for myself, happy with the knowledge that I don’t care if anyone else ever uses them, which is quite a liberating feeling! And something that (for me, anyway, at this point in my life where I have less time to code than I’d like) I can only do with vibe coding.

  And I love the idea of barefoot developers! That people who want to build solutions now have so many more tools to be able to do so.

  (Related: I recently watched this Theo video about AI startups, where he posits the most promising startup founders aren’t tech bros who think they can solve everyone’s problems with their tech skills; they’re the domain experts who are now enabled by AI to rapidly build real solutions for problems only they can address with their years of experience.)

  We’re at the cusp of something truly incredible, and I’m just super excited to see how all this unfolds. I remember the feeling, back at the dawn of mobile, when the App Store launched — checking leaderboards daily, downloading new and innovative apps, trying them out — and that’s the excitement I’m finding again with every new agentic coding tool being released enabling me to build my home-cooked apps.

• The General Problem

  27 Sep 2025

  I was entering my credit card transactions manually into my personal finance app YNAB*, and got distracted by a mini vibe coding project — what if I made a personal web app to send screenshots of my bills (not the full PDFs of course) to a LLM to get CSVs I could upload into YNAB**?

  This led me down a rabbit hole where I ended up making a side app to compare LLM processing speeds on OpenRouter in converting images of credit card transactions to CSV. The “test” was to parse one screenshot of transactions (about 11) into a given format (date, description, memo, incoming, outgoing), timed, and checked against the expected number of transactions and summed total.

  Observations and conclusions:

  1. Gemini 2.5 Flash beat the crap out of every other model I tried (the full list: Claude Haiku 3, Mistral Small and Pixtral, GPT 5-mini and 4o-mini, Llama 3.2 Vision and 4 Scout, Gemini 2.5 Flash Lite and Gemma 3, Qwen 2.5VL, Grok 4 Fast, Kimi VL, GLM 4.5V). 4 seconds to parse the page, vs. 10+ for the next nearest model! I’d previously just done this with ChatGPT, but got bored waiting for it to make me a nice Markdown table, and this is blazingly fast in comparison.
  2. Local models are still currently awful. I fed the same prompts to some qwen and llama models and their ilk (whatever can run on my M4 Pro MacBook Pro with 64GB RAM), and they kept making up output or missing results. Maybe I just don’t have enough experience working with local LLMs, but I fear it’ll be a while before they get good enough for anything other than specialised tasks.
  3. I was trying local LLMs because of cost, but each month of credit card bills costs me under 10 cents to process. Worth it!
  4. With all the time I spent doing this, I could have manually entered all my card transactions by now. Cue XKCD comic about “The General Problem”! There’s always an XKCD comic.

  The GitHub repo is at yjsoon/ynab-llm-formatter. Upload one or more images, and get back a CSV in the upload format YNAB expects. That’s it! Try it out, and let me know if you actually end up using it. (And if it’s not quite what you need, fork it and send it to your own AI coding agent to edit!)

  * It’s designed for automatic transaction imports using Plaid, which… isn’t supported here. Sigh.

  ** I just re-read the second half of this sentence, and there’s way too many acronyms for this to have made sense.

  

• Vibe coding with an AI character

  16 Sep 2025

  One issue with AI-assisted coding is how easy it is to just ignore what Codex/Claude Code says. It’s (currently) important to review the code that AI produces, but it’s so tempting to just skim it, assume it’s correct, and pay the technical debt later.

  In order to force myself to read the AI’s output, I set up my AGENTS.md/CLAUDE.md files to make the agent swear like a Singaporean Ah Beng when talking to me, and now I can’t help but pay attention to this imaginary platoon-sergeant-turned-coder screaming obscenities while coding. Try this out with whatever amuses you enough to keep you reading!

  Grateful to live in a time where I can provide increasingly stupid vibe coding tips 🙏🙏🙏

  

• Teaching in stick shift

  6 Sep 2025

  Half a day into my vibe coding class, I found myself teaching participants about APIs, private keys, databases, CRUD, and edge functions — things I’d only normally cover after 6-10 days of intro web.

  And everyone did fine directing their LLMs to set up CRUD, incorporate API keys into the back-end, and much more; all without knowing a lick of HTML, CSS, JS, React, or TypeScript.

  Which makes me wonder if programming instructors are like driving instructors at a point in the past. We might be at that point where driving instructors saw their learners taking to driving with automatic transmissions, since all they wanted was to get from Point A to Point B, and didn’t feel the need to learn everything about internal combustion and gear shifts and stalling, even as their instructors wanted to teach them the ALL-IMPORTANT FUNDAMENTALS — conceptual knowledge and practical skills which the instructors loved and enjoyed and had gotten really good at.

  So the fundamentals as we know them just… aren’t, any more? That’s quite a shift (sorry) to process. I’m sure we’ll continue to have professional programmers — like how we have professional drivers who understand the ins and outs of torque and transmission — but it’s nice too that everyone else is now enabled to just get where they want to go.

  

• If you teach the Singaporean on the road

  5 Sep 2025

  A former student posted this heartfelt piece about why they’re leaving Singapore, titled “if you meet the singaporean on the road”. It’s a great read, and resonated strongly with their audience on Twitter.

  

  I met up with them for lunch yesterday, amidst the throngs of students leaving school early from their Teachers’ Day celebrations, just to catch up and wish them well on their next step. Afterwards, I just sat for a bit and marvelled at how lucky we are as teachers — to get these precious glimpses of young lives growing and becoming themselves.

  Happy Teachers’ Day to all who teach and who’ve taught: my family, friends, colleagues, and of course teachers.

  (This student will be in the SF Bay Area, and if anyone in my network is happy to lend them any kind of support, let me know; I’m sure they’d appreciate the connection.)

Further back in time

• 23 Aug 2025

  DHH interview
• 20 Aug 2025

  You can just do things (or, new blog engine!)
• 19 Aug 2025

  Warped
• 4 Aug 2025

  Application for professional slopper
• 1 Jul 2025

  Sibeh awesome! Committed!