Ejection seats (pic 1)

A post on NCD sent me down a rabbit hole reading about ejection seats. Do we have anyone here who can share some first-hand knowledge about the designs? I didn't fully appreciate these products before: thousands of parts, multiple precisely timed pyrotechnic charges, and big consequences for failure. That sounds like a very stressful development project.

The picture above is a British pilot ejecting from his Harrier in Afghanistan in 2009. He was lucky and was able to resume flying.