@fillippone
There are a couple of threads in the forum about them (I don't remember the stories and how it ended, or not). But just to add, Changelly.com can ask you to perform the KYC at any time if they (their system) think your transaction is linked to "suspicious activity."
And this, without an explanation from their part. So you won't even know why the system flagged you.
Changelly service reserves the right to apply the AML/KYC procedure to certain Users, addresses and particular transactions of crypto assets. Application of the AML/KYC procedure is based on Changelly service internal policies and aimed at preventing and mitigating possible risks of Changelly service being involved in money laundering as well as any other illegal activities.
https://changelly.com/aml-kycAnd I too classify the service as centralized, one simple reason, among many, is there is a team behind the business who control everything from A to Z. It's a non-custodial service because it doesn't store users' coins/keys but not decentralized, who has the power?
Thats interesting to know.
Thanks.
So, to recap, the best definition is: centralised, non-custodial.