Azure AZ-204 case studies
Azure AZ-204 · Put your knowledge to work in context.
Microsoft Certified: Azure Developer Associate is an intermediate-level Microsoft certification aimed at developers who build end-to-end solutions on Azure. Microsoft lists its product as Azure, its role as Developer, and its subject as application development, and notes it was last updated 01/14/2026. The Azure AZ-204 case studies are 5 cases and about 4,538 words.
1Reconciliation Functions: 504s, duplicate files, and a nine-hour drain
Fabrikam's order-reconciliation platform runs on an Azure Functions app (Consumption plan, Windows, .NET 6 in-process) with three functions: an HTTP trigger POST /reconcile that starts a run, a Service Bus trigger that drains 40,000 settlement messages each night, and a Blob trigger that ingests each carrier file. Symptoms: POST /reconcile returns 504 after roughly 230 seconds whenever a carrier resends a large batch; the Service Bus worker needs about nine hours to drain the queue and never exceeds 20 instances; and support sees the same carrier file processed twice, producing duplicate credit notes.
890 words, about 4 min2Cosmos DB hot partition under a fixed RU budget
Northwind's product catalog lives in one Cosmos DB for NoSQL container of about 25 GB. The partition key is /tenantId , and one wholesale tenant owns roughly 70% of the documents - about 17 GB in a single logical partition.
927 words, about 5 min3Removing secrets from an App Service, a Function app, and GitHub Actions
Tailspin's customer portal is an App Service (Linux, .NET 8) plus a Function app that read and write Blob Storage and Service Bus. Today 14 connection strings and 3 storage account keys sit in App Service application settings and in a local.settings.json committed to the repository; a penetration test flagged this.
869 words, about 4 min4A five-hop order pipeline that cannot be traced, at 200 GB/day
An order flows through API Management, an HTTP-triggered function, a Service Bus topic, a second function, and Cosmos DB. Application Insights is enabled on both function apps and APIM with default adaptive sampling.
926 words, about 5 min5Retry storms, duplicates, and a rate-limited payment provider
A payments gateway running on a Consumption-plan function calls a third-party PSP. The PSP allows 100 requests per minute per API key, returns HTTP 429 with Retry-After , and returns 503 during maintenance windows lasting up to 30 minutes.
926 words, about 5 min