Passed the SC-900 last Thursday with an 820 out of 1000. The passing score is 700, so I had decent margin. I came in with a general IT background but no dedicated security experience, and I studied for about 14 days at roughly 1.5 to 2 hours a day. Wanted to share what worked since most guides I found were either too shallow or way too deep for what this exam actually tests.
The exam had 45 questions covering four domains: security, compliance, and identity concepts at roughly 10–15%; Microsoft Entra capabilities at 25–30%; Microsoft security solutions at 35–40%; and Microsoft compliance solutions at 25–30%. The Entra and security solutions sections were the heaviest and that's where I concentrated most of my prep time.
Microsoft Learn has a free SC-900 learning path that's genuinely good — I went through all of it in week one, then spent week two doing practice questions and reviewing anything I got wrong. Don't just memorize product names. Understand what each tool does and when you'd reach for it versus a similar product. That distinction drives most of the harder questions.
The SC-900 is on the conceptual end of Microsoft certs. They're not asking you to configure anything, just to know what things are and what scenario they fit. If you understand Zero Trust principles and the shared responsibility model you've got a big chunk of the foundational questions covered already.
820 is a strong score for two weeks of prep. I passed at 760 after about 10 days and thought the Microsoft Purview compliance section was the trickiest part since there's a lot of feature overlap between products. The Microsoft Learn modules are genuinely the best free starting point available.
One thing I'd add for anyone still prepping — Microsoft Sentinel vs. Defender vs. Purview keeps tripping people up because the use cases overlap in descriptions. Write out a one-line distinction for each product and review it the morning of the exam. That framing probably saved me 3 or 4 questions.
MeasureUp practice tests are worth looking at if you want something more structured than free resources. They're not free but they mirror the real exam question style closely. I did two full mock exams the day before and passed comfortably the next morning.