This list contains a few projects built using blockchain, https://due.com/blog/101-top-blockchain-companies/

This is a mixed list, but contains blockchain projects built using Ethereum platform, https://en.m.wikipedia.org/wiki/List_of_highest_funded_crowdfunding_projects

I do not know about the technical aspects of building a blockchain project, but do know that you can use blockchain simulators like Ethereum testnet, multichain, openchain, hyperledger, bitcoin testnet to test and try your blockchain project.