AZ-305 Azure Infrastructure — 3-month study plan for a solutions architect
Taking the AZ-305 in 12 weeks. I've got the AZ-104 (Azure Admin) and have been working in Azure environments for about 3 years, so this isn't starting from zero. But the 305 is notably broader in scope — it's a design exam, not an administration exam, and that shift requires a different kind of preparation.
The four domains are identity, data storage, business continuity, and infrastructure. Business continuity is where I'm putting the most time — RTO/RPO tradeoffs, choosing between backup, Site Recovery, and paired regions depending on the scenario.
Architecture decision questions are genuinely hard because they're rarely clear-cut. Azure always has 4-5 services that could technically solve a problem and the question is which one fits the constraints in the scenario. That kind of judgment takes hands-on experience more than memorization.
Anyone else come from AZ-104 directly to 305? How big of a jump did you find it?
Business continuity is worth 25%+ of the exam and it's where people lose the most points. Know when to use Backup vs ASR vs geo-replication vs paired regions for different scenarios. The constraints in the question (cost, RTO, RPO, region availability) determine the answer — practice reading them carefully.
John Savill's AZ-305 YouTube series is the best free resource for this exam. He's genuinely good at explaining design trade-offs rather than just listing services. Pair it with the Microsoft Learn paths and you have most of what you need.
Hands-on labs matter more for this exam than for 104. You need to have actually built and connected these services to understand their constraints. Microsoft Learn sandbox labs are free — use them heavily in the last month.
104 to 305 is a real jump. The admin exam tests can-you-do-it; the design exam tests should-you-do-it and why. Study the Microsoft Well-Architected Framework seriously — it's the conceptual backbone behind most of the trade-off questions.
Honestly I almost bailed around week 6. The design mindset shift is real and it took way longer than I expected to stop thinking like an admin and start thinking like an architect. What helped me was drilling specific topic areas instead of broad reviews -- something like az 305/questions/azure monitoring and logging design when I hit those gaps, because it forced me to think through the tradeoffs rather than just memorize steps.
I passed on my first attempt with about 3 weeks still left in my plan. Don't give up if it feels overwhelming mid-way, that's just the design-thinking click that hasn't happened yet. It will.
I finished the AZ-305 about six weeks ago while working full-time and honestly the schedule thing was my biggest challenge. What ended up working for me was treating weekday evenings as off-limits and just banking on two solid 3-hour sessions on weekends. That sounds like less time than you'd think you need, but the 305 rewards depth over breadth — if you really internalize the "why" behind each design decision, the exam questions start to feel familiar even when you haven't seen that exact scenario before. The az 305/questions/azure monitoring and logging design section tripped me up early because I kept thinking about it like an admin task instead of a design tradeoff.
Coming from AZ-104 definitely helps but don't let it make you lazy. The mindset shift from "how do I configure this" to "which of these four architectures best fits the requirements" is real and it takes a few weeks to click. I'd say spend the first month just reading scenarios and asking yourself why one answer is better, not just which one is correct.
Honestly I almost bailed around week 8. The design mindset shift is real and nobody warns you how disorienting it is when you've spent years just making things work. What saved me was drilling specific scenarios instead of trying to memorize every service -- stuff like az 305/questions/azure monitoring and logging design where you actually have to justify why you'd pick one approach over another. That's the exam in a nutshell.
If you've got the AZ-104 background you're not starting from zero, but don't let that make you complacent. The 305 doesn't care that you know how to configure things, it wants to know why you'd design them a certain way. Keep going even when it feels like you're not making progress -- I passed with a week to spare and felt like I barely understood half the material until suddenly I did.