Great professor, easy class as a PhD course. Deanna is extremely patient, helpful, and funny. Her lectures are clear, but the content is a bit easy, so that she sometimes ended class 20-30mins early. Quizzes are not hard, but you have to spend some time preparing for it. No curve course, strict grading scheme.

The class was probably the easiest grad level math class I've taken at UCLA. The professor was very clear and accommodating: for example the syllabus issued at the beginning of the year discussed what we'll cover each lecture and what parts of the book we should read to prepare. There were also really helpful ungraded homework sets, questions from which appeared on quizzes and exams, and the answers to which the professor was happy to discuss. While the professor does not post notes, she is willing to send them by email when requested. The slightly irritating thing is that she does have weekly quizzes, which can be a bit stressful. I am generally a fast exam taker and still struggled to finish some of them on time (though arguably that's my bad for not using the most efficient solution or proof method). The quizzes did get easier as the quarter went on (in my opinion), with the last few having more computational and less proof based questions. However, it was stressful that we didn't really know how well other students did on them so it was hard to tell if we should be worried about our grade if we got anything below 100%. The exams were very fair, both in terms of the material and the time allotted. The lectures tended to be a bit boring, often coming directly from the textbook, but there were some topics introduced that the textbook did not cover, and some Matlab demonstrations and showcases of the professor's research.

*Also for 170E*

If I can sum up this class and this professor in three words it'll be: easy but tedious

As the other reviewer stated, be prepared for hours and hours and hours of homework. In fact, I noticed that the professor simply assigns EVERY SINGLE ODD IN THE BOOK for the homework.
Since every single odd is assigned, the hw sets will almost always include some of the stupidly hard proof problems that you have no choice but to look up the solution for.
I didn't find lectures to be that helpful for the hw as Professor Needell gives fairly simple examples that do not help at all for the more difficult problems in the book.
In addition, every now and then a coding problem is assigned IN ADDITION TO EVERY SINGLE ODD IN THE BOOK, but I didn't find them to be that hard, and they were actually pretty fun to do. The tedious part of the coding is that if you don't know Matlab, you have to figure out how to do the equivalent in the language of your choice.

The reason there is so much hw assigned is due to the fact that there are no exams in this class. Instead of exams, you have two projects to do that replace both the midterm and final respectively.
This sounds great until you get the project and realize its just a take home exam. The take home exam was long and tedious, with some coding problems. Sometimes I wished that we just had exams instead, as I would much rather take a 24 hour exam (COVID) than an exam that I have to do over a course of a couple weeks.
That being said, the projects weren't hard, just tedious.

Overall, my review may sound like a lot of complaining, but I'm just saying it how it is. It's easy for me to look back and say "oh the class wasn't that bad" but in reality, I and probably every other person in my class had to spend way more time on this class than is necessary for 170E.
So yeah, easy class, most people probably got A's, but it comes at a huge time committment. So you decide if it's worth it or not.

TLDR: EASY BUT TEDIOUS

COVID QTR - Overall, this was a pretty good class. The lectures were very clear and there were two projects with a bit of MATLAB/R (your choice, could even be C++) coding that were a little long but fun! The weekly homework assignments took a very long time (4-13 hours) and sometimes required me to read a few chapters of the textbook, but towards the end the professor made the workload a bit lighter. If you know calculus i.e. how to compute indefinite and double integrals, you should be completely prepared. Professor Needell and our TA Derek were very knowledgeable and approachable throughout the quarter and recorded their lectures/sections making the class logistics very convenient. Be aware that the class structure may change in the future as this was all online, but I would take another class with this professor again. This was a good class to learn probability and prepare you for any future classes that have a probability requisite.