Asynchronous & Parallel Processing in C# – Practical Implementation Guide

Design and implement efficient asynchronous and parallel processing patterns in C#, showcasing real-world usage scenarios and performance considerations.

Requirements:

• Implement async/await for non-blocking I/O-bound operations (e.g., database calls, API requests, file I/O).
• Use Task.WhenAll to execute multiple independent asynchronous tasks concurrently and aggregate results.
• Demonstrate parallel processing using Parallel.For, Parallel.ForEach, or PLINQ for CPU-bound workloads.
• Clearly explain when and why to choose:
  • async/await vs synchronous execution
  • Task.WhenAll vs sequential awaits
  • Parallel loops vs asynchronous tasks
• Include exception handling, cancellation tokens, and best practices to avoid common pitfalls (deadlocks, thread starvation, over-parallelization).

Deliverables:

• Clean, production-ready C# code samples
• Side-by-side performance comparison (sequential vs async vs parallel)
• Clear documentation and comments explaining design decisions
• Summary of best practices and real-world use cases

Target Audience:
Intermediate to senior C# / .NET developers preparing for system design interviews or building high-performance applications.