What are best practices for testing, deployment, and hosting ASP.NET Core applications?
Quick Interview Answer
Detailed Explanation
Use layered testing: fast unit tests for isolated behavior and integration tests for critical framework and infrastructure paths. Keep tests deterministic and use production-like infrastructure where provider-specific behavior matters.
Build and test releases through CI, publish immutable versioned artifacts, protect deployment secrets, and use environment-specific configuration. Apply database changes deliberately and design schema evolution for the chosen deployment strategy.
In production, configure HTTPS, reverse-proxy behavior, health checks, structured logging, monitoring, process recovery, and least-privilege identities. Prefer stateless application instances for horizontal scaling and validate a release before sending full production traffic to it.
Code Example
# Example release validation
dotnet restore
dotnet build -c Release --no-restore
dotnet test -c Release --no-build
dotnet publish -c Release --no-build -o publish
# Deployment platform then:
# - supplies protected configuration
# - starts the release
# - checks health/readiness
# - routes traffic
# - monitors errors and latency