When preparing my raised bed, years ago, the idea was to make use of the horrible bank up to the fence at the back of the house.
Basically the idea was one 150mm fence panel long the top, but that made it an awkward height at the bottom of the bank, or front of the bed. Many ideas of digging down to make it even, cut the panel down... All involved more wood work, which is not my favourite job 😂.
So, to even the front, I place a single panel, left a gap and the 2 more panels created the front of the level beds. 8 at 1.2m wide, 1.5m deep, all connected in a long row.
The idea of the gap is to add space, it may be vertical, but this creates an area where oragono, lettuce, parsley and many other greens can grow, mostly one's that like the cooler shade.