What's planned
Once accounts exist, you'll be able to follow the colleges you care about, and every college on your saved list will be followed automatically. Each time the site publishes new data, you'll get one email listing what changed at your colleges, in plain language and with the years: a new year of admissions figures, a revised price, a value a college newly reports. Nothing personal goes in the email, only the same public figures the site shows, and unsubscribing is one click.
Every profile also gains a public What changed panel, so visitors without an account can see that a college's numbers moved and when. It was built in October: see Accounts.
Behind the scenes
Changes are detected once, when data is published, by comparing the previous publish with the new files field by field, using the site's lineage records for the years and per-field tolerances so float noise never counts as a revision. A daily job sends digests for publishes older than a day. The spec also settles the email provider (Resend) that accounts will use for sign-in links. Nothing is built yet.