Sides are bamboo (originally supposed to be hotel stair treads)
6' x 11" x 1"
Horizontals are African Mahogany. 10.5" x 1" x variable length.
Sides lean out @ 15 degrees. 11" spacing between the shelves.
Total weight of the bookcase is ~105lbs. Add 100lbs(?) of books.
I saw this design online a few years ago, and of course cannot find it again to see how he did it.
Tools and skills
Typical homeowner tool selection. Drills, table saw, circular saw, Kreg pocket jig, a dozen big clamps, router, sanders. Not averse to buying something new to get this done.
Skills = just on the unskilled side of 'medium'. I can build a mean deck.
Aircraft mechanic and computer programmer (engineering mindset).
Degree of difficulty - the vertical sides cannot be replaced. I only have the two, and so cannot screw up any holes or cuts. The shelves, I have spare material and can get more. At $7 bd/ft, my wallet would cry, though.
How to join the horizontals with no visible means of support? No visible stiles, braces, brackets...
My current thought is pocket screws from under each shelf, into the bamboo sides. I have enough extra mahogany to create enough sawdust to mix with glue and plug the pocket holes.
Secondary thought is screws from the outside of the sides, into the end grain of the shelves. This also involves somehow covering over the screw holes with matching (something). Of course glue with whatever solution.
Due to the off angles, I'm not sure I could pull off dovetails or mortise and tenon.
Other joinery options? Convince me why pocket screws will not work or are a bad idea.
After much cutting, swearing, and sanding...figured you guys would like to see the finished product in its forever home.
In answer to the actual "question", I went with dowels.
Added in progress: