The interviews themselves were solid, and I had a good, detailed conversation with the Head of Engineering. I was explicitly told I would be moving to the next stage. After that, communication stopped entirely. HR acknowledged my follow-up and committed to providing an update the same day, but no update ever came. Subsequent follow-ups were ignored.
Failing to provide even the courtesy of a rejection email is unprofessional, especially given the time and effort candidates invest in preparing for interviews and progressing through the process. This reflects poorly on how the company treats applicants once it no longer needs them.