.NET › Diagnostics & Performance
What are the main strategies for optimizing performance in a .NET application?
AdvancedAnswer
Performance optimization in .NET generally spans four areas: reducing memory pressure (preferring struct over class for small, frequently-used data since structs avoid heap allocation, and using Span<T>/Memory<T> to work with large data without extra allocations); embracing asynchronous programming so I/O-bound work like database queries and API calls doesn't block threads; optimizing database access (AsNoTracking() for read-only Entity Framework queries, selecting only needed columns via projection, proper indexing); and caching frequently-accessed data via MemoryCache, the newer HybridCache (.NET 9+), or a distributed cache like Redis to avoid redundant, repeated work.
// Optimized EF Core query: only fetches the Name column, not entire User objects
var names = dbContext.Users.Select(u => u.Name).ToList();
// In-memory caching to avoid repeating an expensive operation
var cache = new MemoryCache(new MemoryCacheOptions());
cache.Set("key", expensiveResult, TimeSpan.FromMinutes(10));Real-world example A slow product-listing endpoint is sped up significantly by combining three of these techniques at once: adding AsNoTracking() to its read-only EF Core query, projecting only the specific fields the UI actually needs, and caching the resulting list in Redis for 60 seconds to absorb repeated identical requests.