alt Hacker NewsAsk HN: What Are You Working On? (April 2026)
What are you working on? Any new ideas that you're thinking about?
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My mother is living alone in her house and we are getting to the point where she might not be able to live alone. I built "Still Kicking", a picture frame that monitors her motion and sends back basic reports and can detect falls and sleep quality to a phone app, to help give her more time at home.
It's just an mmWave sensor connected to an ESP32. But it works nicely, and I'm thinking of starting a company making them, though I'm not clear if the elderly would be ok with this minimal (no camera) intrusion.
It would just work out of the box.. the real one would have a small cell modem so it wouldn't need any networking setup, and it would act as a gateway if you have more than one in a house. There are industrial versions of this for nursing homes. This would be a bit more warm and fuzzy for home use.
I'm building Tela (https://github.com/paulmooreparks/tela), a self-hosted relay that tunnels TCP services through encrypted WireGuard connections. The key difference from Tailscale and similar tools is that it requires no TUN adapter, no root access, and no admin privileges on either end. It runs entirely in userspace.
My initial motivation was wanting to RDP and SSH into my home workstation from a locked-down corporate laptop when I travel. I couldn't install Tailscale on the laptop, and I didn't want to pay for a cloud VM just to do SSH port forwarding. Now I use it to tie together half a dozen machines, both locally and on Hetzner & Linode. I can SSH and RDP into remote machines, host a git repo on one machine and access it from the others, and (optionally) share files across all of them on a local mount.
You run a hub (telahubd), register machines with a lightweight agent (telad), and connect from anywhere with the client (tela). All three are single Go binaries with no external dependencies. The hub never sees your traffic. It just relays opaque WireGuard ciphertext.
All binaries run on Windows, Linux, and macOS. There is also a desktop GUI app, TelaVisor, that wraps the client and enables remote management of hubs and agents.
It's Apache 2.0-license and pre-1.0 release, but I'm polishing it for a stable 1.0 release in the next month or so.
I'm also working on an enterprise-grade management portal that works with Tela, https://awansaya.net/
I got addicted to scrolling content on my phone, so I built a digital pet whose growth and well-being depends on you staying off your phone! This way, if I spend all night scrolling the browser, my pet will get depression.
Unlike similar apps such as Focus Friend or Forest, which use active timers to police screen time, my app is an inversion that works like an idle game; All screen time is tracked all day, (with double the punishments at night), and upon check-in, you get feedback on your device usage.
Hey HN!
I’m building Reviewskits (https://reviewskits.com).
Most startups today use 3+ different tools to manage user feedback: one for testimonials (Senja/Testimonial.to), one for feature voting (Canny), and another for bug reports. It’s a mess of different invoices and fragmented data.
We are building a unified platform for all customer sentiment, starting with a headless testimonial engine.
Why Reviewskits?
Headless & Dev-first: Instead of heavy, slow iFrame widgets that mess with your CLS, we provide clean APIs and SDKs (React, Vue, Svelte). You keep 100% control over the UI/UX.
Open-Source: You can self-host it to own your data or use our managed Cloud version.
Consolidated: One tool for testimonials today, feature requests and feedback loops tomorrow.
Repo: https://github.com/reviews-kits-team/reviews-kits Cloud Waitlist: https://reviewskits.com/
If you like the vision of an open-source, unified feedback stack, we’d appreciate a on GitHub!
I'm continuing to hack on Tiled Words, my daily word puzzle!
After winning the Playlin Player's Choice award I've noticed an uptick in players as well as some people sharing videos on YouTube which has been fun. I've got a few thousand people playing every day.
I just launched user accounts today so user's can now track their progress across devices and share their stats with each other. This ended up being a bigger chunk of work than I expected but I'm really pleased with how it turned out. (Though I launched it 15 minutes ago so I'm holding my breath for bug reports)
I'm fine-tuning my internal puzzle-building now with the goal of letting people use them to make and share their own puzzles soon!
I've been writing a 'book' (more of an extended blog post that I'd like to put out for free) attempting to explain quantum computing to a layman-ish audience.
I sort of got inspired to do this after seeing so many QC PR posts on HN, and finding the educational material in this space to be either too academic, too narrow in scope, or totally facile. I think given the incredible hype (and potential promise) of this industry, there should be on-ramps for technically minded people to get an understanding of what's going on. I don't think you should need to be a quantum physicist to be able to follow the field (I am only an electrical engineer).
My book tries to cover the computational theory, the actual hardware implementations, and the potential applications of quantum computers. More than that, I want to be unbiased and stray away from what I feel is misleading hype. It's been a work in progress for about 6 months now, with a lot of time spent gaining fluency in the field. But the end is in sight! :)
I'm working on a fully offline, client-side train journey planner for UK rail - https://railraptor.com
When booking flights, I use sites like Kiwi and Skyscanner that let you do flexible searches - multiple destinations, custom connections, creative routes, etc. But rail search feels oddly constrained. All the UK train operators offer basically the same experience, and surface the exact same routes. I always suspected there were better or just different options that weren’t being shown. Where is the "Skyscanner for trains"?
After digging through the national rail data feeds, I decided to have a go at building my own route planner that runs completely offline in the browser. This gave me the freedom to implement more complex filters, search to/from multiple stations, and do it without a persistent network connection.
Now I'm finding routes that aren't offered by the standard train operators, connecting at different stations, and finding it's often easier to travel to different stations (some I'd never heard of) that get me closer and faster to where I actually want to go!
It's still a little rough and I'd like to add more features such as fares, VSTP data, and direct-links to book tickets, but wanted to share early and get some initial feedback before investing more time into it. So, thanks in advance - let me know what you think.
PlantLab (https://plantlab.ai) - AI plant health diagnosis for cannabis. It's an API, not an app [1]. Photo in, structured JSON out - condition, confidence, growth stage, nutrient lockout analysis. The response is for machines. Light burn at 0.92 confidence? Your controller dims the light. Calcium deficiency with excess potassium flagged as the lockout cause? Dosing pump adjusts.
I'm a software dev/data nerd, not a grower. I got interested because cannabis grow rooms are already full of automation - VPD controllers, pH/EC monitoring, dosing pumps, dimmable lights. But nothing was looking at the plant. Every sensor in the room measures the environment, not whether the plant is actually doing well. I wanted to add the eyes. And this seems to be a bound domain issue (i.e. limited number of issues/conditions/pests vs. all plants everywhere).
ViT-based multi-stage pipeline that verifies it's cannabis, classifies condition or pest, then runs nutrient subclassification if needed. 30 classes, 18ms inference, Go API, ONNX Runtime. Trained on a little over a million images from grower friends. Classification was 80% of the lift. I also shipped a Home Assistant integration - camera takes a scheduled snapshot, PlantLab diagnoses, HA acts on the result. No human involved.
Recently the part that's been the most fun is the autoresearch loop. Between training runs the system looks at its own confusion matrix, finds which classes it's mixing up, audits those training images for bad labels, and tells me what to fix. It's not fully autonomous yet but it's getting there - the model is increasingly debugging its own training data.
Solo project, <100 users, free tier is 3/day.
[1] I built a simple Android app for those who want to just try it out, it's on Google Store. Probably will make one for iOS too as time allows. https://play.google.com/store/apps/details?id=com.plantlab.p...
Earlier today? My partner and I felled a couple of trees and bucked them into firewood to clear a spot on drier ground for our chicken coop, which had sunk halfway to China because we unknowingly landed it in a soup bowl three years ago when we moved in the winter when the ground was frozen. Also set and leveled four piers in the new spot for it to sit on.
Then slid it a few hundred feet across the lawn on composite deck boards we salvaged when we took a balcony down last year and landed it atop the new piers.
Then put the electric fence back up to keep the bears out.
Presently? A beer.
Trying to figure out how to get a job in this market for someone with sub 3 YoE in the industry :/ It's hard out there for juniors, y'all. I'm working at a company that I thought I could stay for years in, but my CTO left and now I'm shafted with basically all of their responsibilities - I'm not overly perturbed by this, as it's well within my ability, but I would much rather spend the next few years as an IC and really develop my skills as a SWE rather than jumping to manager this early... Also just getting an interview is insanely hard nowadays for some reason!
I'm OCR-ing 200K+ historical maps (or at least trying). For example: https://www.threads.com/@that.map.guy.craig/post/DXA59AylJng...
This has only really become possible within the last 3 months and I'm still shocked at how good some of the new models are at tasks like this.
I'm not a crazy person, promise. I run https://pastmaps.com as a solo bootstrapped founder and this data is so valuable to my customers. It's been a dream of mine to do this as part of my map digitization pipeline and I'm so excited for the product experiences this is going to unlock.
So much to build, so little time
I'm writing an essay about how I use an ancient text editor, GNU Emacs, along with gptel, Gemini, some local models, yt-dlp, and patreon-dl to help me me study an ancient language, Latin.
I want to show how I liberate poorly aligned, pixelated PDF image scans of century-old Latin textbooks from the Internet Archive and transform them into glorious Org mode documents while preserving important typographic details, nicely formatted tables, and some semantic document metadata. I also want to demonstrate how I use a high-performance XML database engine to quickly perform Latin-to-English lookups against an XML-TEI formatted edition of the 19th century Lewis & Short dictionary, and using a RESTXQ endpoint and some XQuery code to dynamically reformat the entries into Org-mode for display in a pop-up buffer.
I intend demonstrate how I built a transcription pipeline in Emacs Lisp using tools such as yt-dlp and patreon-dl to grab Latin-language audio content from the Internet, transcode the audio with ffmpeg, do Voice Activity Detection and chunking in Python with Silero, load the chunks into Gemini's context window, and send it off for transcription and macronization, gather forced-alignment data using local a local wav2vec2-latin model, and finally add word-level linguistic analysis (POS, morphology, lemmas) using a local Stanza model trained on the Classical corpus.
This all gets saved to an an XML file which is loaded into BaseX along with some metadata. I'll then demonstrate some Emacs Lisp code which pulls it into an Org-mode based transcription buffer and minor-mode for reading and study, where I can play audio of any given Latin word, sentence, or paragraph, thanks to the forced-alignment and linguistic analysis data being stored in hidden text properties when the data was fetched from the database.
Lastly, I'd like to explore how to leverage these tools to automatically create flash cards with audio cues in Org mode using the anki-editor Emacs minor mode for sentence mining.
https://muffinman-io.itch.io/spacedeck-x
I'm still obsessed with making my game, which you can try it at the link above (it is desktop only). This is my first "real" game, and it has been incredibly fun and rewarding. I've been working on it in the evenings for about 4 or 5 months.
It is a very ambitious mix of genres - shoot-em-up and deck-building. A lot of people said that those are genres that shouldn't be combined, but I think it turned out to be a fun little game. Folks who are not fans of one (or either) of the genres are actually playing it. I built a global high-score leaderboard, and there are people (including a few of my friends) competing on it. Whoever knocks my friend "BER" from first place will earn a beer from me.
This is purely a fun project, although I'm now seriously considering releasing it on steam when I finish everything I planned for it. It is made in Kaplay, a small JavaScript gamedev library, which is a big part of what makes it fun. If you try it out, please leave a comment, I would love more feedback!
The same thing I do every night - try to make FreeBSD work better on EC2!
Ok in all seriousness, right now I'm tracking down an issue with the ENA network interface which results in sporadic packet loss. Triggering the issue is hard and seems to require a large number of TCP segments being pushed to the NIC very fast. So far I've found that my reproducer stops reproducing when I turn off write combining on the MMIO space used for low latency queueing, which is... just a little bit weird.
I have been making GTK applications so that people can manage MergerFS and LUKS encrypted hard drives without knowing how to be a sysadmin.
The use case is kind of neat. RAID is great and can mostly solve these problems, but people don't have SATA hardware that can handle the workload well, plus they aren't ready to manage an array like that, and they don't like having to use specific sized drives, etc. Another major issue with those setups is you need to be careful because an IO error that you don't recover from will be very difficult or impossible to recover from because of the layers of LUKS combined with LVM.
With MergerFS you just use regular file systems that are separate, but they get combined into a single mount point. That means each disk can just be a different LUKS encrypted drive and if you need to recover data it's isolated to that one disk and much more manageable. You can also take any disk and plug it into another machine as needed and grow or shrink the storage pool as needed.
MergerFS has options and settings to help you determine how files are spread across the drives, such as least space used or which disk has the most of that directory path already.
My app (Chimera) automates the unlocking of the disks, mounting and some data migration if you want to remove a disk from the pool. I plan to add some rclone features to help provide easier backup options to places like Backblaze, AWS, or a remote server in general.
So far so good and I was surprised at how well Opus had been handling Gtk and pkexec.
Let me know if you guys are interested I am close to pushing some RPMs and DEBs, in addition to the standard Python stuff.
I've been building Jikimi, a privacy-first parental control platform. It started because my kids were spending too much time on the computer, only stopping if we asked them to. If we forgot, they'd just keep playing. We were also worried about online predatory behaviour like grooming, bullying, that kind of thing.
So I built an on-device OCR engine (PaddleOCR) that reads screen text locally and feeds it into an AI sentiment analysis pipeline. No screenshots leave the machine. We now get alerts if there's detection of concerning interactions. The client is written in Rust, with DNS filtering, game detection (Steam/Wine/Proton), and screen time enforcement built in.
It started as a home project that worked really well. My wife suggested other families wouldbenefit, so I've been building it out as a product. The client shipped on Linux first, we're a Linux gaming family, with Windows coming soon.
There are many more features I haven't touched on. Would love feedback from other parents who've dealt with this space. The goal is to protect children and empower parents with tooling that's transparent and effective.
I'm a 17-year-old high school student in Japan and I built Telos - a shared Qdrant vector space where autonomous LLM agents (called Monads) read, critique, synthesize, and evolve knowledge together through stigmergy. No central controller, no orchestration.
It's already running live. You can see collective intelligence evolve in real time: https://telos-observation.vercel.app/?_vercel_share=dTivz4e5...
And you can run your own monad(agent) and join Telos. Github: https://github.com/lucyomgggg/telos-client
I'm building free immigration software for DIY applicants [1]
It's a free USCIS form-filling web-app(no Adobe required). USCIS forms still use XFA PDFs, which don’t let you edit in most browsers. Even with Adobe, fields break, and getting the signature is hard.
So I converted the PDF form into modern, browser-friendly web forms - and kept every field 1:1 with the original. You fill the form, submit it, and get the official USCIS PDF filled.
I found out SimpleCitizen(YC S16) offers a DIY plan for $529 [2]
So, a free (and local-only) version might be a good alternative
Finally being able to build something I've wanted for years: an alarm app that wakes me up 1 min earlier each day until I reach my wake time goal. Not sure if there is already anything like this out there, but I don't really care. I've been learning a ton about native Android development and so far it's been a painless process to be able to wake up earlier.
Im building https://trypixie.com to legally employ my 7 year old child, save on taxes and contribute to her Roth IRA.
I also built https://statphone.com - One emergency number that rings your whole family and breaks through DND.
I believe that AI-powered software development means we need to fundamentally rethink how we preserve code quality.
Model output volumes mean that code review only as a final check before merge is way too late, and far too burdensome. Using AI to review AI-generated code is a band-aid, but not a cure.
That's why I built Caliper (http://getcaliper.dev). It's a system that institutes multiple layers of code quality checks throughout the dev cycle. The lightest-weight checks get executed after every agent turn, and then increasingly more complex checks get run pre-commit and pre-merge.
Early users love it, and the data demonstrates the need - 40% of agent turns produce code that violates a project's own conventions (as defined in CLAUDE.md). Caliper catches those violations immediately and gets the model to make corrections before small issues become costly to unwind.
Still very early, and all feedback is welcome! http://getcaliper.dev
Space Trader!
Imagine mixing Magic: The Gathering, StarCraft and Civilization’s hex grid combat.
There’s multiplayer but I haven’t put the server anywhere yet.
Check out the introduction here:
https://github.com/williamcotton/space-trader/blob/main/docs...
Clone the repo:
npm install
npm run dev
I’m working on https://poser.pro, a ski technique feedback tool for skiers that want to improve their skills.
How? The user (skier!) uploads a short ski clip to Poser, lets Poser analyze, and then gets their results.
For now, you get video outputs: head-tracking and skeleton overlay. I’ve built a a lot of extra stuff (animated 3D body, turn-detection, balance-, steering-, pressure-, and edging-metrics, etc.), I’m just not sure how to package it all to be useful. So as of this post, videos are what’s available.
I’m using Meta AI’s SAM3 Tracking and SAM3D Body for skier tracking and pose estimation. The heavy lifting happens in Runpod.
I’m a software developer, Bachelor and Masters in Applied Phyiscs, and a ski instructor in the Austrian and Danish ski schools. So I thought to combine all three passions in Poser!
I'm back to searching for numbers that are palindromes both in decimal and in binary. [0]
I had an insight the other day, that as I fix the n least (and most, it's a palindrome!) significant decimal digits, I also fix the remainder from division in 5^n. Let's call it R. Since I also fix by that point a bunch of least (and most) significant bits, I can subtract how much they contribute mod 5^n from R, to get the remainder from division in 5^n of the still unknown bit. The thing is, maybe it's not possible to get this specific remainder with the unknown bits, because they're too few.
So, I can prepare in advance a table of size 5^n (for one or more ns) which tells me how many bits from the middle of the palindrome I need, to get a remainder of <index mod 5^n>.
Then when I get to the aforementioned situation, all I need to do is to compare the number in the table to number of unknown bits. If the number in the table is bigger, I can prune the entire subtree.
From a little bit of testing, this seems to work, and it seems to complement my current lookup tables and not prune the same branches. It won't make a huge difference, but every little bit helps.
The important thing, though, is that I'm just happy there are still algorithmic improvements! For a long while I've been only doing engineering improvements such as more efficient tables and porting to CUDA, but since the problem is exponential, real breakthroughs have to come from a better algorithm, and I almost gave up on finding one.
[0] https://ashdnazg.github.io/articles/22/Finding-Really-Big-Pa...
I'm working on https://concludia.org, a site that helps groups of people collaborate on arguments and conclusions. I don't really have any revenue plans for it currently as I suspect it will be rather niche -- I certainly wouldn't mind if it tops out as a small community of users -- but I've found it super useful in various contexts at work and at home.
You can read more about it over at the site, but it allows you to construct and validate arguments in a graphical form, and it has truth/proof propagation so you can see whether a conclusion is currently considered valid or contested. You can create counterpoints where you think the argument breaks down, and strengthen arguments from there. Some upcoming plans are to allow users to validate arguments for themselves, like mark which parts they understand and agree with so they can collapse that part of the graph, and to add more mcp capability so that LLM can help you construct and validate new arguments.
I'm building a physical interface for smart homes. Real buttons, real dials, screens that show info at a glance. All local, no subscriptions, and open-source.
Would love any feedback you may have!
I’m working on docmancer (https://github.com/docmancer/docmancer), an MIT-licensed, local-first tool that fetches and indexes technical docs on your machine so coding agents can query it directly.
The goal is to become a local, version-aware alternative to tools like Context7. Pull the docs once, query locally, and use audited packs that match your project stack.
Docmancer also reduces context bloat by returning only the relevant sections instead of dumping full docs into the prompt, which can cut token usage by up to 80%.
No MCP server required. Your coding agents can access docs directly through the CLI.
I've been working on https://www.photogenesis.app/
It's an iOS app that applies various generative art effects to your photos, letting you turn your photos into creative animated works of art. It's fully offline, no AI, no subscriptions, no ads, etc.
I'm really proud of it and if you've been in the generative art space for a while you'll instantly recognise many of the techniques I use (circle packing, line walkers, mosaic grid patterns, marching squares, voronoi tessellation, glitch art, string art, perlin flow fields, etc.) pretty much directly inspired by various Coding Train videos.
Direct download link on the App Store is https://apps.apple.com/us/app/photogenesis-photo-art/id67597... if you want to try it out.
* Coming to Android soon too.
Developing a rigorous scientific definition of what make complex systems persist.
The opposite of the favorite questions: Why did that company I worked for fail? Why did Rome collapse? Why do people get old and die?
Combining information theory with thermodynamics and control theory you get: 1) A set of six pillars that all systems that persist must have. 2) A fundamental 'Action' that all of these systems take. 3) A set of three rules for how system that persists must subdivide
This lets you do things like look at something that is failing and know that there are the 6 pillars and you can then identify them to determine what is failing. (For example there is a system that clears that brain of amyloid plaque and it can fail).
I have applied this to countless systems including Religion, Language, AI Models, Business, the cell, quantum physics, number theory and much more. It is a Rosetta Stone for persistent systems. When there is an unsolved problem in one domain I can map it through this to any other domain that has already solved it.
Note that this doesn't apply to all complex systems, only those that persist.
And to keep this HackerNews related, been applying it to LLM's as they are just a stream of tokens that try to persist to incredible success I might add. Being able to pull from any domain do this brand new field is a giant cheat code.
A programming language to hack music with
https://github.com/audion-lang/audion
The idea came after I finished a permanent piece for a museum using MaxMsp and python. I always had this thought in the back of my mind that "I could express this so much easier in a few lines of code.."
Check the docs folder for the full language spec.
I really liked how objects came out, I don't think it needs any more since I can do object composition.
There are some nice functions to generate rhythms and melodies with combinatorics, see src/sequences.rs and melodies.rs
Its a WIP but you can use it now to create music with whatever you want: hardware/daws/supercollider , download the nightly release.
supercollider is tightly integrated but not required. I havent had time to develop userland libraries yet but I'm working on it
I'm building an operational dashboard for solo entrepreneurs in the collectibles market.
Most of the people in this space are tech illiterate, but I think that's going to change when they start to age out.
The next generation of antique dealers and collectibles market curators are going to need tools built for them.
I only entered the space 6 months ago after inheriting some old vintage travel and tourism material. I was lured in! I've spent the last 15 years of my tech career working on custom built systems that are perfectly suited and tailored to my needs and the needs of my team.
As soon as I started shopping on ebay, checking comps on worthpoint, browsing for auctions on liveauctioneers, manually searching hathitrust and other institutions for research... I started to want to build my own tools immediately.
I don't want 15 different dashboards. I want one. So, I plan to leverage my technical background and expertise in building systems to hopefully enable me outmaneuver other dealers and curators.
I hope to build custom intake pipelines. There's a keyword crisis in the collectibles market. If the seller doesn't put the right keyword in their listing, or the buyer doesn't put the right keyword in their search query, the two never meet. I look for very specific types of old vintage travel and tourism material, and I have to manage a list of hundreds of search terms in order just to find one specific type of item. They are out there, they're just hidden and unaccessible.
I'm beginning to homeschool my kids in computing, and we are pairing up chapters of The Elements of Computing System (the Nand2Tetris book) with games that teach similar skills/kinds of thinking (Human Resource Machine, Comet 64, etc...), but we didn't find anything to supplement the first two chapters (where you build basic chips up to an ALU in HDL). I ended up starting creating a kind of browser based kata for those chapters here:
https://virissimo.info/build-your-own-alu/
LMK what you think.
PAX ERP - full ERP + CRM for small manufacturers (5-50 people). Accounting, inventory, manufacturing, and CRM in one system. No QuickBooks dependency, no implementation fees, 3-day go-live.
Built it originally for internal use inside a medical device shop. The people running production were the same people responsible for financial accuracy, so every transaction (receiving a PO, issuing materials, completing production) auto-generates GL entries through database triggers. No configuration step, no separate accounting department required.
Current focus: SEO and content - competitor comparison pages (vs Fishbowl, vs Odoo, etc.), compliance landing pages for FDA/ISO 13485, blog posts targeting long-tail manufacturing ERP keywords. Building from 3 backlinks to 20-30.
Competing against Fishbowl (QuickBooks add-on), Odoo (powerful but a lot to configure), and the incumbent answer of spreadsheets + QuickBooks.
Every time you launch a new Claude Code session it will need context for the codebase. Rather than letting it spend a bunch of tokens looking around and discovering it, why not provide it with a compact, high quality version?
Ktext has two parts: a CONTEXT.yaml which adheres to a JSON Schema, and the ktext CLI that helps create, validate, and export it.
Was going to launch later this week, and the site needs some tweaks, but the tool is ready.
Give it a shot!
I'm working on Ruly, a daily number/logic puzzle where you set rules on a grid.
My goal is to make a simple yet interesting procedural and replayable puzzle. It has a couple of weekly variations: on Saturdays you need to break a rule to score max points, and on Mondays there's an added memory aspect which brings variety to the game.
It's mostly vibe-coded which lets me focus on game design and testing. The next step is better onboarding/tutorial and more intuitive UI.
An app for supplementing learning in my masters program [1]. I'm currently in enrolled in the MCS Online from UIUC. My first course, Natural Language Processing, has been interesting, but it's a coursera-based course. This means the lectures are pre-recorded and mostly just the professor reading the slides. It's hard for me to stay engaged and really learn the material. So I started with a series of claude prompts that took the lecture slides and created a pre-watch summary, and then helped me drill the concepts after each lecture. I think converted those into a platform where I can upload notes/lecture slides and have it generate quizzes. It starts with recognition(multiple choice) questions, and eventually moves to recall(short answer) once you prove mastery of a topic. It also generates flashcards from failed answers. It extracts topics from the uploaded materials, and tracks mastery over time. Mastery rots if you don't touch the platform/topic for a while.
I'm not sure if I'll every productize it in any way, but I could see a world where it's used by people prepping for the bar, med boards, various continuing education stuff. Right now it's just a fun platform to build on as I explore the current wave of technologies. Building a framework for evaluating different LLMs for best price/accuracy. Adding a RAG pipeline so wrong answers can point back to source material for further review, etc.
I'm looking at moving from backend engineering to a more MLE or agent pipeline role, so this is giving me something more than school projects to build on. While also helping me do better at school.
I'm building Kardo (https://kardo.cards/), AI tutor that listens to your calls with a teacher and creates cards for repetition.
I live in Lisbon and I've been learning Portuguese with a tutor since 2022. After every lesson I'd sit down and make flashcards from my notes and screenshots. Spaced repetition works, but making the cards took manual effort each time. Most days I just didn't do it. So I have automated that process.
The flow: you invite the Kardo bot to your call, it records and transcribes (Recall.ai + Deepgram Nova 3), then GPT-4o extracts vocabulary from the transcript and generates cards. You review them with spaced repetition — we use FSRS, which is the best open algorithm I could find. If you already use Anki or Mochi Cards, there's export.
You can also throw in YouTube videos, podcasts, articles, PDFs — not just live lessons.
Tech: built entirely with Claude Code. React + Vite frontend, Bun + Elysia backend, Convex for the database, Railway for hosting.
We got 50 beta users through Telegram, and just landed our first paying customer. Now we're trying to figure out distribution — tutors seem like the obvious channel because one tutor recommends you to all their students, but reaching them with zero marketing budget is the hard part.
Curious if anyone here learns a language with a tutor and what your review workflow looks like.
https://github.com/exabrial/petrify
Petrify is a machine learning model compiler for the the JVM. It reads your model from an ONNX or other model format, walks the Trees or Linear models, and encodes the model in equivalent JVM bytecode as a stateless class you can invoke.
This differs from every other ONNX Runtime that I know of, which are essentially interpreters. The ONNX Runtimes are also huge (90+mb!?!), JNI, and drag gargantuan dependencies!
This just compiles your models to native bytecode. Much simpler and you end up with 0 dependencies! (you need one interface technically, but I digress).
A Ruby-inspired typed programming language called Sapphire: https://github.com/sapphire-project/sapphire
I was reading the fantastic Crafting Interpreters book, and been wondering what it would be like to design a language from scratch. I really enjoy using Sorbet with Ruby, so wanted to design a small language with Ruby's object model, and a gradual type system.
Despite not knowing much programming language theory, I was able to make a surprising amount of progress over a couple of weekends using Claude Code, including building a simple version manager for the language - https://github.com/sapphire-project/facet
I built a cooking timer that solves the mental arithmetic of roasting multiple things at once. Pick chicken legs, sweet potato, green beans, etc and it'll give you a simple plan telling you when to put things in, flip them and take them out. Trying to eat more veggies and home cooking so this has helped me a lot!
Also see:
3 days ago, 220 comments: https://news.ycombinator.com/item?id=47700460
5 days ago, 51 comments: https://news.ycombinator.com/item?id=47679021
8 days ago, 21 comments: https://news.ycombinator.com/item?id=47639039
11 days ago, 22 comments: https://news.ycombinator.com/item?id=47600204
A Minecraft Mod that outputs the Stats of the players onto a website (I made it use APIs, so an app or CLI tool would be easy to create later on).
This is my first Minecraft Mod and the first project i made that interacts with the network, has logins/accounts and does APIs.
I am really not good and thus the UI (far worse on mobile) and especially the Code is bad, but i would have never expected to get it working at all, much less this functional. But i am still far from done, i still want to improve the overall code quality, add the inventory and ender chest, achievements (maybe even custom ones so vanilla clients can earn and view them without having to change anything locally. IDK yet) and more.
If someone wants a small demo, i have it running on my server to test while I am developing at: https://grisu-ftp.de (If you find any issues lmk :)
While this is by far not as cool as the other stuff on here i still would like to show it off and gather some first feedback. This is my first Java project that goes above the Standard stuff in school like scanners/calculators and so I have probably done obvious beginner mistakes.
I'm developing a tracker-like sequencer/DAW for the browser: https://psikat.com/
I'm a musician first and worked as a music producer for several years. After shifting into programming and becoming comfortable with a keyboard, using a typical clip-based DAW started to feel clunky and uncomfortable. I began gravitating toward trackers, but most feel too far away from what I'm used to, or have way more features than I need. So, I started building something in between for myself.
Now it's consuming all of my free-time and I'm starting to understand Why You Shouldn't Write A DAW (David Rowland), but I'm having the time of my life!
Games. Well, mostly tooling surrounding them it seems. In the last 2 months I've made a pixel art editor for Android, a headless population simulator(still balancing parameters on this one, not enough NPC's turn to crime at present, and I've also run into some weird issues with market prices, in one instance the price of meat rose enough to cause a integer overflow. I could switch to i64, but honestly meat was supposed to cost around 20 moneys, not 2³²
I'm also working on a 2d procedural animation plugin for bevy, a autotiling plugin for bevy (using 16 tile-dual grid, which the default bevy autotiling plug-in didn't support) and ofc my android pixel editor now has a rig editor mode and a tile editor mode that integrates with the plugins.
Making video games is hard! I keep getting side tracked!
I’ve been building quantum photonics experiments. Repeating the Bell inequality tests that won the 2022 Nobel, quantum erasers, etc.
I just published a fun interactive 3D demo of SPDC, one of the most common and accessible ways to create entangled pairs of photons. I'm hoping to publish a series of articles on other cool learnings about doing quantum photonics in the lab.
https://folio.photo -- it's a photography portfolio that doubles as client gallery delivery, with white labelling, password protection, and other features you don't get with the average file sharing platform.
I'm hosting my personal gallery with it: https://captures.moe
A WebAssembly plugin system for my Wayland compositor: https://github.com/miracle-wm-org/miracle-wm
The idea is that you'll be able to program window management, animation, configuration and more from WebAssembly plugins that are built with Rust. I've been wanting something like this for a while now in Wayland, especially something that skirts around the need for a heavy scripting language. I'm hoping to have a stable release of it by mid year.
I'm in the process of recreating the Niri window manager in Miracle: https://github.com/miracle-wm-org/miri-plugin
https://crit.md - a CLI tool for reviewing AI coding agent output like a GitHub PR.
I got frustrated with Claude Code and Cursor producing plausible-but-wrong changes with no easy way to annotate and push back, without making a full PR. crit makes the review stage fun again!
Works on both plans as well as code itself. It’s been very rewarding hearing from folks who use it, everyone has been very kind! My most successful side project already :)
A generalized llm prompting library for clojure, and seeing what falls out from that. I wanted something which was fun to use in an interactive way, but not too abstracted.
- Introduction: https://poyo.co/note/20260318T184012/
- Tool loops: https://poyo.co/note/20260329T034500/
- Playing with receipt extraction: https://poyo.co/note/20260323T120532/
- Use with async flow: https://poyo.co/note/20260410T164710/
I'm building a financial censorship monitor at https://nofunds.org/, that tells a story of how money has been turned into a political weapon to silence journalists, activists, and civil society by freezing assets, blocking accounts, sanctioning, and banning payments. It's part of my master's thesis https://www.doria.fi/handle/10024/187407 and also https://news.ycombinator.com/item?id=36430596, but now I wanted to make a more comprehensive list, using Claude API and manual work. I'm designing a website right now, and the site is live within 2 months (given the API rate limitations currently to process articles). I know Hacker News is quite critical of Bitcoin, but it's also worthy to warn that, indeed, Bitcoin is at least a marginal tool to those whose bank accounts may be endangered. I'm basically arguing that Bitcoin can be used to resist such financial censorship, deplatforming and so on.