The DMA sets out a list of obligations and prohibitions for Apple, Alphabet's (GOOGL.O) Google, Amazon (AMZN.O), TikTok owner ByteDance, Meta Platforms (META.O) and Microsoft (MSFT.O) which the six companies had to abide by on March 7.
Apple has in recent weeks announced a series of changes from allowing apps developers to distribute their iPhone apps directly to consumers instead of through Apple's App Store to letting developers distribute their apps to users in the European Union outside of the App Store.
The company told apps developers, business users and rivals at a day-long hearing organised by the European Commission that it has redesigned its systems to comply with the DMA.
"We were guided first and foremost by ensuring that we've complied with the law. And then second, that we did it in a way that was consistent with our values and consistent with the language that we've developed with our users over a very long period of time. And we think we've accomplished that," Apple's lawyer Kyle Andeer told the hearing.
"And I think we're focused on it from a user perspective. Now, it's not to say that we're not focused on the impact of developers, but I think from our perspective first and foremost, we'll be tracking very carefully what's the impact of all of these different changes on the user experience that we've delivered to our customers for 15, 16 years through the iPhone?"
Meta will present its compliance efforts at a separate hearing on Tuesday, Amazon on Wednesday, Alphabet on Thursday, ByteDance on Friday and Microsoft next Tuesday.
Companies that fail to comply with the DMA risk investigations that can lead to fines of as much as 10% of their global annual turnover.
(This story has been refiled to add a dropped apostrophe in the headline)
