Their chief scientist found me on LinkedIn and contacted me directly.

There were a number of phone calls with their recruiters and four phone calls with engineers. Constant follow-up from their recruiters who wanted to know what questions were asked (perhaps the right hand doesn't know what the left hand does).

There was no programming test. The final onsite involved lots of questions.

The entire process was very positive and friendly, and their enthusiasm was higher than average. I did not receive or detect any signs that the interview was going badly. When I asked about the next steps, they said they would make their decision within a week.

I never heard back from them. It was really strange, not even a canned rejection email.

Write some code which translates English into a language like Pig Latin.