Ask HN: Most interesting tech you built for just yourself?

LLaMA.go - open-source framework for LLM inference on regular CPUs [0]

It took me about a month of full-time, hard, day and night coding (including weekends) to finally build a solid piece which can handle some crazy CPU workloads of tensor math.

[0] https://github.com/gotzmann/llama.go

Happy Friday! I have built a document-reading app to help me curate, visualize, and recall my knowledge as I read and annotate research papers - https://www.KnowledgeGarden.io

The app also extracts data from documents, such as urls, keywords, and references, and generates a downloadable pdf report with annotations and extracted data.

I built a sprinkler system that has 14 zones. Using raspberry pi and relays. It has a web interface and can run on schedule or manually. Worked out to be better than a kickstarter I backed, lono, that turned out to be dud and the company went under.

I plan to open source it. have to clean up the code. Built with python flask, GPIO and a small custom PCB that interfaces pi with the off the shelf relay boards.

Todo - flutter app - 3D printable enclosure to package the entire set. - basic logo etc.

I built a ‘prezi file fixer’. In the old days, prezi used pez files which could get ‘corrupted’. Not really corrupted, but when someone scaled some objects too much down, the prezi editor could no longer solve the issue, and the prezi file (really: a presentation) could be considered lost.

Solved it locally at first: unzipped the pez file, searched for the smallest objects, and scaled them up. It might look a bit funny (that ball which had been made much smaller would have been scaled up), but people could again fix it using the prezi editor.

Used this manually to ‘fix’ other peoples presentations, in which they send me their pez file, I would ‘solve’ it and send it back (usually: they would invite me to be a co-author, I would make a copy, fix that and make them editor to that copy). Used to do this quite a lot on the prezi forum.

In the end automated it completely: made a service in which one could upload a pez file, my NAS would decompress it, fix is, compress it again, and mail a link to the corrected pez file.

Software is defunct as problems have disappeared (and changes to prezi way made it no longer work).

Incidentally not my first prezi product: I guess that was the Android app that made it possible to view a prezi on an Android phone or tablet, ways before Prezi themselves made the Android app (I think they already had the iOs app, not sure). [That app ran in more then 50 countries, but that is another tale;-0]

When I was in college, registering for classes was always a pain since a lot of classes would fill up almost instantly once online registration opened, then it was just a game of constantly refreshing to see if any seats had become available.

After struggling through that for a few semesters, I decided to automate it. Started out with a script that would take course IDs as input and check for openings every few minutes (used selenium/beautiful soup I think) then text me via twilio whenever a seat was available. The next semester I updated it so it would even sign me up for the course automatically.

Also came in handy to get myself and a few friends into the coveted wine tasting class our senior year.