AZ-305 (Designing Microsoft Azure Infrastructure Solutions) is the exam behind the Microsoft Certified: Azure Solutions Architect Expert credential. It sits above the associate tier and tests something genuinely different from the exams before it: not what a service does, but which service, pattern, and trade-off you should choose given a set of business and technical constraints. This guide covers the four design domains AZ-305 actually tests, the prerequisite Microsoft enforces at the certification level, how hard the exam really is, and a study approach that matches how the exam is structured.
What kind of exam AZ-305 is
AZ-305 is a design exam, not an operations exam. You will rarely be asked what a setting does; instead you are given a scenario - a company with existing infrastructure, a compliance requirement, a budget constraint, a recovery time objective - and asked to choose the architecture that satisfies all of it at once. Many questions have more than one technically valid answer, and the correct choice is the one that best fits the stated constraints. This is the biggest adjustment for people coming from associate-level exams: you are being tested on judgment and trade-offs, not recall.
The four AZ-305 design domains
Microsoft's current skills-measured outline groups AZ-305 into four design domains. Weights shift slightly with each periodic update, but the relative emphasis has been stable for some time:
- Design identity, governance, and monitoring solutions (roughly a quarter of the exam) - Microsoft Entra ID (formerly Azure AD) architecture, role-based access control, Azure Policy and management groups, Key Vault, and logging and monitoring design.
- Design data storage solutions (a little over a fifth) - choosing between relational and non-relational stores, storage tiers and lifecycle, and data integration and analytics patterns.
- Design business continuity solutions (roughly one in six questions, the smallest domain) - backup strategy, disaster recovery patterns, and high-availability design across regions and zones.
- Design infrastructure solutions (close to a third, the single largest domain) - compute choices, networking topology, application architecture, and migration strategy.
The AZ-104 or AZ-204 prerequisite is real
Unlike most vendor certifications, this is not just a suggestion. You can register for and sit the AZ-305 exam at any time with no registration-level block. But Microsoft will not award you the Azure Solutions Architect Expert credential from a passing AZ-305 score alone - you must also hold Azure Administrator Associate (AZ-104) or Azure Developer Associate (AZ-204). If you pass AZ-305 without either of those, you are left without the Expert title until the condition is satisfied. Plan your path with this in mind: earn AZ-104 (or AZ-204) first or in parallel, not as an afterthought.
How hard is AZ-305, really
AZ-305 is a genuine step up from AZ-104, and the jump surprises people who assume it is just 'AZ-104 with harder questions.' It is not primarily harder because of unfamiliar services - most of the services appear in AZ-104 too - it is harder because you must hold several competing requirements in your head simultaneously and reason about which one wins. Long scenario stems, case-study-style questions, and answer options that are all technically feasible are the norm rather than the exception. People with strong AZ-104-level knowledge but no design experience often underestimate this exam on a first attempt.
How to prepare for AZ-305
A study plan for AZ-305 should look different from an associate-exam plan, because memorizing service facts will not carry you through design scenarios. A structure that works well:
- Start from a solid AZ-104 (or AZ-204) foundation. If your hands-on Azure experience is thin, close that gap first - AZ-305 assumes you already know what the services do.
- Study by domain, not by service. Work through identity and governance design, then data storage design, then business continuity, then infrastructure, building a mental checklist of trade-offs for each (cost vs performance, simplicity vs resilience, managed vs self-hosted).
- Read Azure Architecture Center reference architectures for common patterns - hub-and-spoke networking, landing zones, multi-region failover - since AZ-305 scenarios frequently mirror these patterns directly.
- Practice with scenario-heavy questions, not flashcards. The exam format rewards being comfortable reading a long stem and identifying which one or two constraints actually decide the answer.
- Time yourself. AZ-305 runs 120 minutes for 50 questions, and long case-study stems can eat time fast if you have not practiced reading them efficiently.
Format, timing, and passing score
- Length: roughly 120 minutes.
- Question count: roughly 50 questions, mixing multiple-choice, multiple-answer, and longer scenario or case-study-style items.
- Passing score: 700 out of 1000 (70 percent), the same scaled bar used across most Microsoft exams.
- Study time: commonly 8-12 weeks on top of an AZ-104-level foundation for someone studying part time, since much of the effort goes into learning to reason about trade-offs rather than learning new facts.
Who should take AZ-305
AZ-305 fits people who already design systems - choosing services and patterns before a team builds them - or who are explicitly targeting a Solutions Architect, Cloud Architect, or senior infrastructure role. It is not the right first Azure exam for someone without real Azure experience; the full Microsoft certification path shows where AZ-305 sits relative to AZ-104, AZ-204, and the specialty exams so you can see whether it is your logical next step or something to aim for later.
The bottom line
AZ-305 tests architecture judgment across identity, data, business continuity, and infrastructure, and it will not hand you the Solutions Architect Expert title unless you also hold AZ-104 or AZ-204. Come in with real Azure experience, study by domain and trade-off rather than by service, and lean on scenario-style practice rather than recall drills. That combination is what actually closes the gap between passing AZ-104 and passing AZ-305.