SIAM Journal on Mathematics of Data Science

A very new journal, just received acceptance notification this morning. The review process was extremely long, so it is not advisable to submit if you urgently need results (I probably won't consider submitting again).

Here is my timeline:
May 1, 2022: Submitted
Early December 2022: First review, minor revisions (only given 20 days to revise)
End of December 2022: Resubmitted
June 27, 2023: Accepted

The reviewers were quite professional. We responded with a 10-page A4 paper response letter... but there were no particularly fatal issues. It mainly involved adding explanations to certain parts, removing/modifying confusing sentences, and improving the overall presentation of the paper. It took almost half a month (during which I put aside all other work and focused solely on this revision) to resubmit the revised version at the end of December.

And now, at the end of June (today), I finally received the acceptance notification. The reviewers' responses were all 1-2 sentence long, saying that all questions have been well addressed (but why did it take almost 7 months for them to review...).