Ask HN: What are you working on? (September 2026)

Posted by david927 1 day ago

What are you working on? What have you been curious about lately?

327 points | 1000 commentspage 38

ahallan 19 hours ago|

Description on the tin.

I found it hard to get fares and timetables for the Elizabeth Line in London between X and Y quickly hence I built this as an experiment using AI tooling.

ocd 1 day ago||

I'm needlessly reinventing the wheel in replacing almost every part of my X11 environment like a menu, bar, wm+hkd (except terminal since I don't want to mess with carrying terminfo around) to be portable and not at all interdependent.

AI is making it possible to (expeditiously) have everything I want or need on Linux or BSD written in POSIX shell or C is doing wonders for me. The initial effort and time pays off in knowing it will essentially function as intended forever, and no developer can make changes that disrupt my workflow or preferences for my environment.

RobinL 1 day ago||

I've been experimenting for a year or two making games that make mental arithmetic practice fun for kids. The latest is https://rupertlinacre.com/keep_it_going/ an infinite rollercoaster, which I think is one of the more successful attempts. There are various others on the homepage. My son also really likes arithmetic annihilation and maths vs monsters.

dobreandl 1 day ago||

I'm building an self hosted, privacy friendly attribution and marketing suite targeting mobile apps. The market is owned by a few, branch, appsflyer etc, and its impossible to become a new MMP without spending ridiculous ammounts on money on their platforms, so I'm trying to build something different, and more provacy friendly without reliying on them.

https://grovs.io

Godsend69 23 hours ago||

To ensure your self-hosted solution doesn't rely on external tracking, consider adding a Telemetry Blocklist to block unwanted data collection. This is a free tool that can help you maintain user privacy. https://join.lightinthedarksolutions.com

Godsend69 23 hours ago||

[dead]

xyst 1 day ago||

this still works if user has ad blocking at dns and user device? Plus most ad blockers strip off the common URL parameters for "attribution"

dobreandl 3 hours ago||

yes it does, our focus is on mobile, and on Android we have 100% success rates, while on iOS around 98%

gmitrev 1 day ago||

Working on https://nadir.dev, a small app for running daily technical knowledge tests. It started just as a way to see if depending on claude-code so much recently dulled my expertise in Ruby/Rails but it turned into something bigger after some friends asked me to add non-technical topics, so now it's both for developers and "normal" people.

aliasxneo 1 day ago||

Spending almost all of my time working on DNTLS (https://dntls.net/). Yesterday I was able to create secure mTLS tunnels over IPv6 for direct P2P to my co-founder's desktop in SE Asia (I'm in the US). He was able to load a website I was hosting locally on my machine. I also tested coordinating through a relay to avoid publishing my public IP and sending all traffic through the relay to hide my IP entirely. We more or less recreated the "old" internet in a way except everything is mTLS and E2E encrypted.

spreadsheettria 1 day ago||

Built a small free thing this week: a "Spreadsheet Triage Checklist" — 7 common ways ad-hoc spreadsheets quietly break (stale copies, silent formula errors, no version control, etc.) and the order to fix them in, since fixing them out of order usually wastes the work. Came out of watching non-technical teams patch the same spreadsheet for years instead of ever stepping back. Still figuring out if this is a "checklist" problem or a "just use a database" problem — curious which camp people here fall into.

eszett 1 day ago||

https://cou.sh, https://jun.is and https://abr.ac — some experiments on offline-first crdt

onion2k 1 day ago||

I'm making a WebGPU renderer with WebGL fallbacks, with a path tracer for 'photo mode', specifically targeting agents writing web 3D things. I'm not especially far into it though. It doesn't use 3D models; there's a DSL for making things.

There's a demo app here that only works on desktop - https://fab.ooer.com/ (scroll down in the right hand menu to quality and change to 'trace' for photo mode)

lvduan 16 hours ago|

I built this sql formatter <https://sql.leuduan.work> for my own use - it works by parsing the SQL query to AST using native engines where possible (for BigQuery it use GoogleSQL library, for MSSQL it uses Microsoft ScriptDOM, the rest uses Apache Data Fusion Parser) and from the AST it re-generates the SQL query in a consistent formatted style. You can throw in all kind of badly formatted SQL queries and it will work just fine. Hope you find it useful!

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