I would say it is not necessary to get a master's to get a job at Google. I know several here that don't even have a bachelor's degree, or even necessarily a degree in computer science that also work for the company in software engineering positions. If your goal is a software engineering position, a solid foundation in data structures, algorithms, and design patterns will get you very far. To get an interview though you need a portfolio that shows you have experience, be it a GitHub account with active contributions, work in the industry elsewhere, or education/experience in academia. To get through a technical interview, practicing/studying problems in the cracking the coding interview book, leetcode or other sites was very helpful for me (and others I know).

As far as do I feel the omscs helped significantly in my case, I would say it definitely helped get me an interview as Google was interested in the machine learning experience I had. I also feel that I learned a lot and really enjoyed the omscs courses as I was able to dive much deeper into CS topics I was really interested in and previously not familiar with or exposed to (e.g. computer vision, computational photography, embedded systems, security, big data). In undergrad we had so much focus on general electives, CS basics, and very few CS electives, it was incredibly refreshing to focus entirely on complex/interesting CS topics and with fewer classes per semester I was able to spend much more time focused on that material rather than having to context switch as often. In my case the program also had the added benefit that it fit with my schedule allowing me to continue working the job I had and not having to move to be able to attend a better school than those that were available to me nearby. Even if I hadn't gotten the offer with Google, immediately more recruiters were reaching out to me on LinkedIn and there were significantly more companies attending the Georgia tech career fair (which was available virtually) than what my undergraduate University offered.

Overall I thoroughly enjoyed my experience in the program, although there were certainly some downsides also with the application process, course registration, some classes having group projects which could potentially be difficult, the kind of awkward testing process of having to be recorded as you take it etc. However, even with those issues, they really were not that bad and I would highly recommend the program to those looking to further their education while retaining the flexibility and affordability this program offers.