A sourcer reached out and set up the first-round technical interview. It was a one-on-one with a lead developer from a random team. I passed the round, and the sourcer scheduled my final round, a four-hour session, during the week I told her I'd be out of town. She said she'd reschedule, then ghosted me.

I haven't gotten a single response from her or the other HR person I emailed after a month of weekly follow-ups. Extremely unprofessional.

Given a list of words, a starting word, and an ending word, figure out the minimum single-letter mutations, using the words in the list, to get from the starting word to the target word.