As I recall, they tend to start the senior folks at grade 15. They have to get approval for starting at any step above step 1, and I don't know how often that approval is granted.

They are very open about all this during the process.

That's right. There's no set grade or step for engineers, but most of our senior engineers start at a 15. Your grade and step (and therefore your pay) are determined by previous experience and previous pay.