What 595 hackers are building in June 2026: baby trackers, formal proofs, and a JVM in Go

The basement workshop, June 2026 edition

Hacker News runs a monthly "What are you working on?" thread, and the June 2026 edition drew 595 comments. It reads less like a product launch board and more like a census of what independent builders actually make when nobody's funding them. Two currents run through it: a wave of AI-tooling, and a quieter, deliberate push against the AI default.

The names you'd recognize

A few well-known builders dropped in with deeply unglamorous status updates. The founder of tarsnap cperciva was polishing release docs: "FreeBSD 15.1! Scheduled to be announced 2026-06-16 00:00 UTC." An engineer who worked on HHVM at Meta, now running signalbloom.ai, was shipping "a new CLI for dirac and a paper that may or may not ever publish." And an OpenBSD hacker brynet was blunt about the economics of the work: "Making rent as an open source developer… Desperately trying to attract new monthly sponsors," linking a literal "wall of pizza" sponsor page.

The anti-AI undercurrent

The sharpest pattern wasn't another chatbot wrapper. It was builders defining themselves against the current moment. A founder building in the EU BrunoBernardino tagged his post "[NO-AI]" and described Uruky, a Kagi alternative whose paying customers "after being a paying customer for 12 months" can download a copy of the source, a license model suggested to him in a past HN thread. A solo dev holistio is building a publishing platform that runs against the tide: "Strictly human content, pagination instead of endless feeds, one-off payments instead of subscriptions… public profile scoring instead of secretive algorithms." And a parent jkantola built a baby-tracker, Vaava, where "all the user generated data is stored only on device… There is 0 behavioural analytics."

Even an HR-tech founder genekrapivin pitched the inverse of the trend: "While most of the HR tech is rushing to use black-box AI, I built the exact opposite. It's a transparent, math-driven fitness engine," and promptly drew a warning that automated CV screening is "legally questionable" in Europe.

The deep technical cuts

Then there's the genre HN exists for: projects with no business plan and a great deal of love. A JVM "entirely written in go," Jacobin. A formally verified, simplified motion planner addaon, reaching for "the big hammer of arbitrary precision" to fight numeric stability and treating Sturm's theorem as an axiom "for now." A collaborative knowledge system Totem "built entirely in Rust without any HTML or web-tech." And the most charming of all: Magic: The Gathering over webcam, with newly added "whole-frame detection on an interval" so you can mouse over an opponent's video feed and see what their cards actually are.

The best exchange in the thread

The single funniest reply landed on a founder pitching an app to detect whether a 'make $10k a month' video is lying. A high-karma reader addaon had a one-line review: "There's a Unix CLI tool that implements an accurate version of this… check out /bin/yes."

What the thread shows, taken whole, isn't a burnout-pivot crisis or an AI gold rush. It's a working ecosystem where a fractional CTO recovering from burnout, a kids' education startup, a privacy search engine, and a guy proving a motion-planning algorithm correct all post the same week. The loudest signal is how many builders are now choosing local-first, human-made, no-tracking on purpose.