Leaving a couple of inches at the ends, pocket screws every 6 inches will hold the cabinet together. Add extra pocket holes if you think you need them.
Tightened securely, the combined strength in al the joints hold the cabinet securely.
I myself build with 3/4" thick wood on all sides and use 1 1/4" pocket screws.
The commercial cabinets use even 3/8" thick material.
Optional construction: (inset panels)
Frames: 1x stock
Panels: 1/4" stock
Grooves in frame to accommodate 1/4 stock
Bottom and shelves: 3/4" stock
Doors: 3/4" stock
Hinges: European style
Assy: pocket holes and screws to secure frame.
NOTE: peruse some books on cabnetry, with this type of construction.