Disks fill up quietly. On a computer used for programming, much of that space is folders nobody remembers making: a node_modules for every website you ever tried, a Rust target folder for every project, a Python environment for every notebook. Roomy shows you where the space went and clears the junk in one go.
What it does
Point Roomy at a disk or a folder. It scans using every core of your computer and draws what it finds as a treemap, where each block's size is how much space it takes. The biggest folders are listed beside it, so you can zoom in on the one that's surprisingly large.
The Developer junk tab collects the build folders and caches that programming tools make again whenever they need them. Tick what you want gone and move it to the Trash. The Duplicates tab finds exact copies of the same file, such as the photo you saved three times.
Open source
Roomy's code is on GitHub, along with a tutorial that builds it chapter by chapter, from a first window to installers and automatic updates.