https://www.futuretechpodcast.com/podcasts/iconomi-ervin-kovac-coo-ethereum-blockchain-based-digital-asset-management-platform/ what interests you begins at 5:20
"With these types of new digital assets security, custody is basically the key we all know what happened with some of the exchanges so the security of the assets of our users is our top priority. We have developed our own hot and cold security system that safely stores all these assets and it is very simple to use for the end user.
Some of these assets dont offer multi sig wallets by themselves and thats one of the systems we developed. Our system is like this: it goes from hot to cold based on the projected needs of these assets ever being to be moved. The lowest level is a multi sig contract with the highest number of participant or signatories required. They are all over the world and dont know each other. This is the level we dont expect to need to move often. There are some additional requirements based in to the smart contract that I cannot give out. So this is lowest level. As you go higher the criteria for security lowers. There are lower number of signatories in these smart contracts for the funds to move and when you get to the top you have some buffers for the small percentage of the total assets that basically insure the liquidity for the platform and these assets are controlled by the server and are naturally the most exposed. We solve this exposure with insuring them. So our hot wallets are insured so we have that covered and as you go lower all of these are done offline with hardware wallets, etc
There are multiple levels of cold and hot storages and each of them is more or less complicated depending on the projection of how often those funds have to be moved."
unfortunately there's no good answer for the parity incident
The parity hacked library was a incident that should not happen, as we we're insured many times that the funds have been moved from parity wallets after other incidents in the past.