azure-functions

Use the .NET Isolated Worker model and register services in Program.cs via HostBuilder.ConfigureServices. Inject dependencies like IOrderProcessor or ILogger through the function class constructor, and configure middleware with ConfigureFunctionsWebApplication.

Use the Node.js v4 programming model, which registers functions directly in code via app.http() from the @azure/functions package. Define the handler, HTTP methods, auth level, and route in a single TypeScript file without any JSON configuration.

Use the Isolated Worker model, since the in-process model is deprecated in .NET 8 and later. The isolated model gives full control over Program.cs, dependency injection, middleware pipelines, and independent framework versioning via Microsoft.Azure.Functions.Worker.Sdk.

Socket exhaustion happens when a new HttpClient is instantiated per invocation. Register clients once with services.AddHttpClient() in Program.cs and inject IHttpClientFactory, or use module-level singleton clients in Node.js and Python.

Consumption plans default to a 5-minute timeout, configurable to 10 minutes via functionTimeout in host.json. For longer workflows, use Durable Functions orchestration with the async HTTP 202 pattern or move to a Premium plan.

Cold starts occur when the platform spins up containers dynamically. Mitigate them by using the Flex Consumption or Premium plan, enabling warmup triggers, and minifying deployment bundles.