Posts

So I started reading a paper about diffusion (the original DDPM paper) and I was quickly out of my depth. I needed a refresher about probabilities, and actually even more basic stuff like exponential and integration. And I thought why not share the notes here! So this blog post is the content of a python notebook about exponential and the normal distribution, exported to markdown with jupyter nbconvert. It’s not deep or anything, just a nice refresher for myself. Kind of a pain to write math formulas and get them displayed in my Jekyll blog but got it working with Mathjax. ...

Google did me dirty this week and I’m salty, so let me tell you. The other day I received an email informing me that my YouTube Premium subscription had been renewed, which surprised me because I canceled it about 6 months ago, and I haven’t missed it ever since (thanks, yt-dlp!). I first thought it was my daughter’s shenanigans, but after a closer look I had only “paused” the subscription instead of canceling it, and Google conveniently failed to inform me it was going to be restarted… No advance email like “your subscription will restart in a few days,” just “whoops, we restarted your subscription and you’ve been charged 13 euros, teehee.” ...

Just a quick update to say I am still making progress on the Password Game Agent project I mentioned last post. I have now reached up to step 16 where we need to solve a chess position… Seems like a suitable job for a reasoning model ! The main changes that enabled going from step 11 (Wordle answer) to 16 were adding a “search tool” based on OpenAI web search tool and changing the reasoning effort from “medium” to “high”. The current version of the code is here : https://github.com/goverture/password-game-agent/blob/master/manually.py I’m still making regular changes and trying new ideas to make progress. I’ve noticed we often seem to get stuck for various reason (for instance a badly recognized Capcha), so I want to add a new step to ensure that we make progress consistently, or backtrack, in order to not get stuck.

There is this javascript game called The Password Game where you have to chose a password, following increasingly ludicrous requirements. Agentic coding/research is all the rage today and I got the idea of making an “agent” that would solve it. Conceptually it’s just about calling a LLM in a loop, giving it the proper tools and context until it solved the task at hand. Here’s where I got so far, using ChatGPT 4o and Playwright MCP (only gave it the navigate and type tools for now). It’s solving correctly the first few steps, but gets stuck at the “sponsor” rule because it cannot view the image. The next step is to give it access to the playwright’s screenshot tool. Let’s see how far it can go ! ...

Another May update ! Not much going on as usual, rainy season arrived in Ho Chi Minh city so we get some strong rain and nice sunsets. Yesterday we got the announcement that Pocket was saying goodbye. Kind of bummed because I found the service convenient, though I just used it as a link bookmark (I never cared much about the reading mode, I always go to the original link - though apparently that worked well with the Kobo e-reader). Anyway I switched to a self-hosted alternative immediately: Wallabag. It’s kind of sluggish but it does the job, and it has an Android app so I can still “share link” to save a link from my phone. ...

So MCP is all the rage these days, and it’s not very complex: it’s basically a standardized way to provide tools to LLMs. So you have an RPC server that provides a description of the tools and the parameters they expect, and your client (a LLM based application) can connect to it and tell the LLM what tools are available, and the LLM can decide to call them when appropriate. Easy stuff and the SDK provided do most of the heavy lifting. ...

Unsurprisingly with a newborn and a very sticky 3 years old at home, I haven’t been doing much in the past 3 weeks. Since I stopped working on it, I’ve released my thematic crossword generation app, Prosettr, to a complete (and expected) indifference (zero traffic came from the HackerNews announcement, and I got about 10 likes from LinkedIn). Oh well, it was a fun project anyway and I’m quite happy with the result! ...

My son Liam was born this Monday! He is healthy and everything is good. I haven’t touched the computer for the week, and as a result I don’t have anything technical to share. The week before however I gave a try to Browser Use, a tool that allows LLMs to use the browser more effectively. I haven’t read in detail how it works but it seems to highlight the interactive areas (buttons etc.) and then take a screenshot for analysis, instead of only sending the DOM as text. It worked pretty well, I was able to fill a form entirely with it (prompting it to not press submit!), and to use Google Translate as well. I don’t have a special use case idea for it at the moment. ...

Not much going on these days. At work, we started migrating some apps from Google App Engine to AWS, which gave me a chance to learn about AWS CDK. As a learning step, I’ve made a small template to deploy a static website on S3 + CloudFront for the frontend and ALB + ECS for the backend, with some CloudFront behaviors, Route 53, and ACM certificates sprinkled in. As far as I know, it’s a standard architecture (though I need to lock down the S3 permissions a bit more, add logs to CloudWatch, etc.), and it’s really nice that it is reviewable by our security guy before we deploy it. And also, it can be deployed to staging first and later on to production with little to no changes. ...

February went by in a blink! I barely had any time for myself this month between work, a pregnant wife, and my 2-year-old being in the “I want papa only” phase. These days, the first thing I do in the morning is play Lego. It beats doomscrolling, but at 7 a.m. and before my coffee, it’s tough to be creative. Here’s an elephant I made this morning—the trunk moves. I’ve also rewritten a big part of the backend of Prosettr.com. In a HackerNews thread about Donald Knuth (Donald Knuth’s 2024 Christmas Lecture: Strong and Weak Components), I learned there was an improvement to the algorithm that my app is based on, Dancing Links. I’m not going to go into much detail here (maybe in a future post), but I procured The Art of Computer Programming Volume 4B, and indeed, the improved version uses half the memory, with each option’s items having only up and down links, and no left and right links—those being replaced by a “spacer” node. Here’s my original implementation in Go I made while following the chapter: /backtrack_aocp/main.go. Then I replaced the previous implementation with this one, with some added optimizations (support for secondary columns, using channels instead of an input matrix, another channel to output the solutions, etc.). ...