You only ever use the web app in your browser: the library, voice setup, read-along, check and practice, and the daily review. Sign-in is hosted, so Veritas never stores a password. The browser records your voice clips, and it asks for consent before it does.
Everything else runs in the cloud. The web server checks who is signed in, shows each learner only their own data, and hands slow work to a job queue. The queue is a table in the database, so jobs survive a restart. Four workers take jobs from it: import, which handles scans and Word files; voice, for preset voices and your own; timing, which finds the moment each word is spoken for read-along; and the study model, which writes and grades questions.
The learning loop runs on top. A check of about 12 mixed questions closes each chapter, and written answers are graded against the source passage. What you miss feeds six ways to practice, and a spaced scheduler brings it back in one daily review across everything you read.
The daily review ran in the closed beta. The fuller learning engine, with a learner profile, the scheduler and mastery tracking, is still being built out.