AIMS Mathematics

Submission in October, revision in December (I checked the time and the modifications could have been completed in just over 20 days. It seems like the editor delayed it for some time, probably due to the pandemic).
After the revision, things went smoothly. The reviewer only asked for minor revisions, and then I paid $1000.
Unfortunately, I received a warning right after submitting. I didn't think much about it at the time, I just wanted to submit it quickly and graduate. But it doesn't matter, the warning doesn't affect graduation.
The biggest advantage of this journal is its fast review process and efficient editing. The time from acceptance to publication is very short. I have seen many domestic SCI journals that still publish papers from 2020 in 2022, so I dare not submit to them.

Here are the main milestones of my paper:
Received: May 5, 2021
Major Revision: June 25, 2021
Returned to the journal: July 9, 2021
Accepted: July 29, 2021
Published online: August 3, 2021
Overall, this journal is quite good. There were three reviewers for the first review, with two positive evaluations and one slightly negative. They provided two weeks for revisions, and the acceptance was quick. Afterwards, there was a publication fee of $1000. I hope this journal continues to improve.