Memory hook: Requirement first; product second; evidence always.
Must remember
Separate functional requirements (what the system does) from nonfunctional requirements (latency, availability, security, cost and operability). Record constraints, assumptions, dependencies and measurable acceptance criteria. A technically impressive design can fail if the organization lacks the skills or budget to operate it.
The Google Cloud Well-Architected pillars cover operational excellence, security, reliability, performance, cost and sustainability. They are tradeoff lenses rather than six independent checkboxes. Managed services can reduce toil; they still need appropriate identity, data, observability and recovery design.
Choose failure domains based on the required outcome. Multiple zones address zonal failures; a regional dependency can still defeat a multi-region frontend. RPO constrains data loss; RTO restoration time. Replication, backups and failover are different mechanisms. Exercise corrupt data and compromised credentials as well as hardware outages.
Scale stateless work horizontally and externalize necessary state. Cache with an explicit consistency/invalidation strategy. Use queues to absorb bursts and decouple failures, while designing retries, ordering and idempotency. Avoid making every dependency synchronous when a business process tolerates asynchronous completion.
Cost decisions compare total ownership, including people, licenses, transfer, idle capacity and risk. Spot resources fit interruptible work; commitments fit predictable usage only after sizing; serverless fits its execution model rather than guaranteeing lowest cost in every case. Sustainability can align with efficiency and right-sizing, subject to location and service constraints.
For a case study, build a matrix: requirement → evidence in the case → design choice → rejected alternative → remaining risk. Distinguish stated facts from your assumptions. Prefer the least complicated design that meets all mandatory constraints, then plan measured future improvement.
Review details
The currently published standard-exam case-study list is Altostrat Media, Cymbal Retail, EHR Healthcare and KnightMotives Automotive. Use the cases linked from the current exam guide, not an old course's list. Before practice, extract each case's existing estate, explicit business/technical requirements, growth, constraints and key tradeoffs. Do not memorize a fixed “product answer” independent of the scenario.
Storage choice also distinguishes file access (for example, managed NFS through Filestore) from block devices and object APIs. VMware Engine addresses supported VMware migration requirements; it carries a different operating/cost profile from moving a small application to a managed container service.
Current case-study recall
These are original revision cues from the published fictional cases. The design implications are reasoning prompts, not claims about a fixed exam answer.
| Case | Stated constraint to retain | What to reason through |
|---|---|---|
| Altostrat Media | Existing GKE, Cloud Storage, BigQuery and event functions; some ingestion/archive remains on premises; reliability and storage economics matter alongside media AI. | Keep hybrid ingestion and repeatable container operations credible. Match summarization, metadata extraction, recommendations and harmful-content screening to appropriate evaluated capabilities. Auditability and cost remain acceptance criteria. |
| Cymbal Retail | Mixed databases/Kubernetes and legacy file-based integration; supplier content must enrich a product catalog; associates must approve, reject or edit generated content. | Separate extraction/generation, relevant search and human approval before catalog publication. Secure customer interactions and measure discoverability/conversion; do not automate away the explicit review gate. |
| EHR Healthcare | A colocation lease is expiring; containerized customer applications must retain on-premises insurer integrations; existing identity is Active Directory; customer availability must reach at least 99.9%. | Plan hybrid identity/connectivity, consistent container environments, proactive alerts and migration waves. Preserve the stated legacy boundary rather than proposing an immediate rewrite/move of every integration. |
| KnightMotives Automotive | Vehicle/software fragmentation, weak rural connectivity, legacy mainframe/ERP, no dealer hardware budget, prior breaches and EU privacy obligations complicate a five-year modernization. | Stage modernization and skills development, account for connectivity limitations, secure data/ML and dealer workflows, and validate simulation/testing. An always-connected cloud-only assumption or mandatory dealer hardware purchase conflicts with the case. |
Before answering, distinguish a business objective from a mandated mechanism. A case mentioning a technology does not mean it must be replaced, and a growth goal does not override a regulatory or budget constraint.
Choose under exam pressure
| Requirement | Choice and reason |
|---|---|
| Strict regional data residency | Keep storage, processing, logs and support dependencies within permitted scope. |
| Small team running variable demand | Prefer suitable managed services and clear operating controls. |
| Two answers both scale | Compare required latency, failure scope, operational burden and cost. |
Traps
- Multi-region frontends do not fix a single-region state bottleneck automatically.
- “Cheapest resource” and “lowest total cost” are different judgments.
Active recall
1. Functional versus nonfunctional?
Function describes behavior; nonfunctional requirements describe qualities and constraints.
2. What does an architecture decision record preserve?
Context, chosen option, alternatives, rationale and consequences.
3. Why identify assumptions in a case study?
An unstated assumption can make an otherwise attractive answer violate the actual scenario.
4. Why test compromised-identity recovery?
A privileged attacker may destroy primary systems and ordinary recovery paths together.
5. What should determine a product choice?
Measured requirements and constraints, with documented tradeoffs.