Posted by david927 1 day ago
Ask HN: What Are You Working On? (Nov 2025)
I was a YC founder in 2006 and now work as a data scientist full-time, but on the side I also do Christian apologetics, helping fellow engineers/scientists/mathematicians seek answers to life's deepest questions.
Some cool articles for the HN crowd:
- [published several days ago] Medical miracles in Lourdes, France recognized by the Catholic Church 2018-2025: https://www.saintbeluga.org/our-lady-of-lourdes-immaculate-c...
- My interview of Evan O'Dorney, a three-time Putnam Fellow and two-time IMO gold medalist, who converted to Catholic Christianity: https://www.saintbeluga.org/veritas-part-i-conversion-of-a-p...
- In-depth scientific overview of Eucharistic miracles: https://www.saintbeluga.org/eucharistic-miracles-god-under-t...
- Conversion testimony by Harvard astronomy professor Karin Oberg: https://www.saintbeluga.org/veritas-part-ii-conversions-at-h...
- It's a personalized newsletter for you
- All data aggregated from sources around the web
- News, weather, newsletters, social media posts, reddit, youtube, etc. all appear in your digest.
- Launching a mobile app as well now but this will be slightly different than the web app. It will use AI to automatically prepare your daily digest based on preferences/settings you give it during onboarding. Each day when you wake up you'll receive a notification of digest being ready, and it will contain all the content you care about for the day ahead (meetings, weather, health data, commute data, news, etc).
It is a recipe app but better, and way more technically capable than anything out there. The goal is to make the best recipe app ever made. With bulletproof easy to follow recipes and smart features to make cooking simple. Everyone deserves good food at home, but good food is complicated and time consuming. An experienced cook can make good food quickly, cheaply and make it look easy. The idea is that Kastanj will have the knowledge you don’t so you can cook like a pro without having to spend years learning everything.
Backstory: I have a note where I write down practical problems I experience in life. I noticed over time that the amount of notes related to food and cooking was growing faster than anything else. I then began searching for a solution. I tried over 50 recipe apps, always the premium version if possible. There are some good apps out there but even the best ones only solved something like 50% of my issues. After enough frustration and search I just decided to start working on my own app. That was 4 years ago... It turns out that solving some of these problems where technically complicated to do, so now I understand why no other app could solve my problems. None the less, after 4 years of work, starting over from scratch 5 times, I have now landed on a solution that technically solves all my problems.
Going forward: Now I am working on filling the app with data and make it easy to use for normal humans. I am on purpose limiting myself to only perfecting the core functionality of what a recipe should be. I intend to launch sometime in 2026. The UI will be small and limited at first, but it is perfect for my needs. Therefore I hope it will also be perfect for someone else. Over time I will enable more advanced functionality and build it out based on user feedback. I know the backend can support 100% of my needs, but I don’t want to make it bloated. Therefore the UI is on purpose focused on only the most important things and then we will build it out with time, together with the recipe creators and end users.
Idea came from one of my clients, where they wanted to use AI agents throughout the organization but at that moment there was no centralized governance or security concepts. This pulls everything at one place and tries to solve the security concept with per-user credentials, which can be provided out-of-band through the MCP protocol (generated a one-time link end-user can use to sign in to the underlying MCP server with OAuth or provide API key)
Now I'm working on a few changes to the app, most notable is moving any plants marked as 'for sale' out from the main section because it turns out people are more greedy than I anticipated and it's getting in the way of sharing the free stuff, cuttings etc.
There's also some demand for a web front end so I might work on that next. (currently only android and ios)
I had an initial boom of downloads in South Africa but lately most new downloads are in USA.
One project is for building rhythm games in multiple game engines and multiple platforms. Currently, it works in Unity, Unreal, Godot, SDL (or any C++ game engine), and MonoGame (or any C# game engine), and runs on Windows, macOS, and Linux. I'm working on adding Love2d (or any Lua game engine) and Bevy (or any Rust game engine). I have a few local prototypes of it working in Unity and Godot, but nothing public yet. Still trying to figure out what kind of game I want to make with it.
https://github.com/neogeek/rhythm-game-utilities
The other is a general purpose game engine in C++ with SDL. It's far enough along that I'm building games in it, but it's more of an exploration into how games are made than a replacement for Unity or Godot. I suppose it could be eventually, but I'm trying to be realistic with what it can do. One thing I'm pretty happy with regarding this engine is that one of the demo repos will automatically build to WebGL and publish to itch.io when changes are pushed.
Lately I’ve worked on a chat history based memory feature that can recall information from every conversation you’ve ever had with ChatGPT and Claude. It’s been particularly useful and also technically fun to implement. Speed has been very important as I do just in time summarisation and a multi stage RAG pipeline, and most LLMs have unacceptable performance. I ended up going with GPT-OSS on Groq due to its ultra low latency often completing full generations before Gemini or ChatGPT APIs return even the first token.
The ability to recall details from conversations going back years makes tasks where I want personalised plans or feedback like 10x more useful, at times I get the AI to ingest tens of thousands of tokens of context to help me better.
- Search campaigns: - automatically crawl website, find the offerings and generate new campaigns - Provide qualitative recommendations such as, relevant terms to include/exclude, e.g. including typos as keywords, improvements on landing page
- Shopping campaign: - Smart labeling of all products to allocate the budget among Top performers, Rising and Ghost products to avoid draining the budget. E.g. instead of a campaign with 10k products with one budget , turn it into 5 campaigns with different budgets doubling down on what works.
Feel free to reach out for a demo
-https://salespark.app/apps/discount-spark: A Shopify app that allows merchants to create more powerful discount codes so they can create stronger offers for their customers.
What I recently built but didn't find a successful product market fit:
-https://wordazzle.com: A word game that's designed to expand your vocabulary with exceptional words.
-https://spicychess.com: Chess, meet boxing! Imagine playing chess BUT you can also smack your opponent. Now, if you smack em enough times to drain their health completely(yes, you have a health bar), you can steal their turn. It's fun, a little evil, but after thousands of $ spent on marketing, never found critical mass.