I understand that this may differ between trading venues, and may perhaps depend on what specifically is being traded, but I would like to understand, in practice, how the post-trade process works in exchange-traded crypto.
For example, on an equities exchange (e.g. SETS), a participant (often a broker) will have an order matched against another participant's order, and the exchange will capture this legally-binding agreement to transact. A central-counterparty clearing firm (e.g. LCH) will novate the positions of both participants (as well as other participants) and net off the multilateral positions at EOD. This removes the risk of counterparty default during the period of time between trade and settlement. However it involves multiple firms performing a chain of operations which can take days to complete.
Crypto-currencies are distinguished by having a distributed ledger - so an OTC transaction can settle 'automatically' without requiring this process (assuming crypto-for-crypto trade). However I think this would be extremely onerous for the blockchain, and so the exchange presumably has some form of netting layer, between the matching engine and the actual on-chain transaction. I can see a few different ways for how this might work but haven't been able to find out how it actually does work.
Can you explain the post-trade process on e.g. Kraken / Coinbase / Binance, and how these firms ensure that two matched orders will settle on-chain?
Do on-chain transactions actually happen when matched on-exchange? Or just e.g. when a user cashes out their exchange account into a local wallet
Does the process differ if one is exchanging one cryptocurrency for another, versus fiat for crypto?
How do they ensure privacy if transactions are trackable in the blockchain? (As a systematic trader, it would be quite bad if other participants knew your positions and which trades you had recently made!)