Hugelkultur on old terraces

Hi.
I'm from Malaysia want to get some ideas about building hugelkultur on old terraces which not so much following countour. The width of those terrace about 8'.
The question is where should I build the hugel? Middle or on edge?
And how big should my hugel?
FYI, I plan to use those hugel to plant veggie for cash. So I estimated about 4 terraces with 100-150' each for start.
Thanks. Hope can hear from all of you soon.

Hello Lanun, welcome to permies!
How much water will the terraces get?  Does the water flow down the length of them?
What has been planted in the beds, is the soil pretty good?
Would you dig into the terraces, drop the wood into the trench and then bury the wood, so that most of the hugel is under the ground or are you thinking of laying the wood on top and adding soil to make the hugel above the current ground level?

Thanks for the reply Miles Flansburg. FYI here we get roughly 2000mm rain per year. And not all water flow down through the lenght of terrace because not on countour. On the terraces was a bush and small native tree. The soil is hill clay. I'm thinking about laying the wood on top and adding soil to make the hugel above the current ground level.
I wanna added some info, that usually end of the year will be heavy rain for 2-3 weeks. After that will hot season with no rain for 3 months. And right now, I was cut down the bushes on the terraces also the edge of it. I want to use it for the hugel as mulching. I plan to finish the hugel before heavy rain so the hugel can retain much water before hot season next year.