Most of the tech companies are letting a mix of recent hires, corporate middle management and in amazon’s case some logistics warehouse workers and specialty project engineers were let go. It’s a pretty eclectic, diverse group of people so its not as hard as it sounds to reabsorb into other companies. If they were all engineers or all HR there might be issues but in an already over-employed economy already 17k jobs won’t even make a dent in just about any sector right now.