Phase 0 — Developer Tooling Foundation

The tools professional .NET engineers use every day: IDEs, debuggers, the .NET CLI, the SDK-style project system and MSBuild. Targets .NET 10 LTS.

41. A bug only appears in the Release build in production and you can't reproduce it in Debug. How do you investigate and fix it?

    Debugging Release-only bugs: the usual causes (removed debug-only code, JIT optimisations exposing races and non-volatile reads, shortened object lifetimes, timing), a systematic investigation with Release builds, logs, dumps and symbols, and preventing recurrence.

    Mid-Level Debugging Build System · 🔗 3 follow-ups · 🛠 1 real-world
42. How do source files, content files and embedded resources work in a .NET build, and how do you read an embedded resource at run time?

    Build items for files: Compile, None, Content and EmbeddedResource, CopyToOutputDirectory and CopyToPublishDirectory, embedded resource naming and LogicalName, reading with GetManifestResourceStream, .resx localisation, and when to embed versus copy.

    Intermediate Theory Build System · 🔗 3 follow-ups
43. What analysers run during a .NET build, how do IDE code style rules differ from CA code quality rules, and how do you configure them across a team?

    The .NET analyser ecosystem: built-in CA code quality analysers and IDE code style analysers, AnalysisLevel and AnalysisMode, EnforceCodeStyleInBuild, .editorconfig severities, third-party analyser packages, suppressions, and rolling stricter rules out to a team.

    Mid-Level Theory Build System · 🔗 3 follow-ups · 🛠 1 real-world
44. How would you enable nullable reference types across a large existing .NET codebase without stopping feature work?

    Adopting nullable reference types at scale: what <Nullable> does, annotations and warnings, flow analysis and attributes, a project-by-project or file-by-file migration plan, handling public APIs and EF Core, and making nullable warnings errors.

    Senior RealWorldScenario Build System · 🔗 3 follow-ups · 🛠 1 real-world
45. Review this Directory.Build.props that turns on TreatWarningsAsErrors with a long NoWarn list. What would you change, and how should warnings-as-errors be used in a team?

    A code review of warning policy: TreatWarningsAsErrors versus WarningsAsErrors and WarningsNotAsErrors, NoWarn versus severities in .editorconfig, CI-only versus local enforcement, AnalysisLevel pinning, and ratcheting a legacy codebase to zero warnings.

    Mid-Level CodeReview Build System · 🔗 3 follow-ups · 🛠 1 real-world
46. Your team's builds have gone from 2 minutes to 15 and incremental builds rebuild everything. How do you find out why, using MSBuild binary logs?

    Diagnosing slow and non-incremental builds: capturing binary logs with -bl, reading them in the MSBuild Structured Log Viewer, finding slow targets, tasks and analysers, spotting broken incrementality, and fixes such as Inputs/Outputs, caching and build server settings.

    Senior Debugging Build System · 🔗 3 follow-ups · 🛠 1 real-world