Really, really good question! Here's a completely free one we recommend using and really like: https://nft-inator.com/ ​ We're building a completely free smart contract & minting website generator (for all Curious Addys & ZenAcademy holders at least, and at a very affordable price at most for everyone else - 1% or less of mint to generate everything end-to-end needed for your entire mint) at https://www.heymint.xyz/ as well that will be out in about a month or so, and this is what we recommend over there to everyone to use to generate their assets for free :). ​ If you have any questions at all or any issues you run into using https://nft-inator.com/, definitely please feel free to ask here and we'll get it answered - it's super helpful user feedback for us as we see what the friction/pain points are for people in building our their NFT projects, as our precise goal right now is to create tools for creators to literally build and launch an NFT project effortlessly from the ground up. ​ Hope that helps! If you have any other questions, definitely don't hesitate to ask!

There's a bunch of code repositories that can be consulted for the generation. ​ Here's one I've read: https://dev.to/rounakbanik/create-generative-nft-art-with-rarities-1n6f ​ This article has good information on pinning the image data to IPFS if that's where you're hosting it: https://docs.ipfs.io/how-to/mint-nfts-with-ipfs/#minty

If your dev can write the contract, they can probably write the code to generate the images and metadata. If they need something to start with, Haships has great resources on GitHub, tuts on Youtube, and a very supportive Discord community. ​ BTW , https://the-nft-generator.com charges a subscription. intead of commission and https://nft-generator.art/pricing charges a fixed fee intead of commission