Update for final round:
I would suggest to always provide proposals with black and white background
- A cube aka container must be part of the logo. Cube in cube and 3D effects are desired.
- A cloud shape is optional but can be a plus if nicely and subtle fitted in
- A C shape is optional but can be a plus if nicely and subtle fitted in
- The logo shall be techy and geometric, abstract
- The logo shall be clear and elegant
A few comments on my favorites
#261 I like the geometric pattern of the hexagon combined with cloud shape (#266 arrangement with cube has potential, maybe like #277 or maybe #276 but rather upside down)
#242 Though very simple the cloud shape combined with the cube comes over very elegant to me. I would prefer a bit more interesting cube maybe like in #277
#277 I like the hexagon, cube or cube in cube composition a lot. The arrangement is a bit too generic yet
#276 I like the gradients and the 3D effects caused by it. The cube arrangement is a bit too generic yet
#190, #156, #141, #105, #45 all combine hexagon, cube with the C shape. Nice play with the shapes, the C and 3D-Effects have potential
To me the logo is very important. I want that by just looking at the logo one associates cloud/containers with it.
Having the C letter nicely and discretely incorporated into the logo is a plus. Playing with the C-letter, hexagon, cube shapes is desired.
Styles I like are:
https://hashicorp.com/ (Main site, Atlas, Terraform , ...)
https://cloud.google.com/container-engine/ (I only like the cube/container in the logo)
http://lattice.cf/ (I like the general application of geometrics, not so much the too intense colors)
I like cubes, hexagons, triangles.
The logo shall be clear, structured and elegant to noble, reflecting simplicity. It should give the impression of precision and reflect complexity and simplicity.
Discrete use of colors is preferred over bright and dominant colors.