Bits of .NET

Response caching at application level is slow. Output caching caches at server level for max speed.

Enable (.NET 7+):

// Program.cs
builder.Services.AddOutputCache();

var app = builder.Build();
app.UseOutputCache();

Use on Endpoints:

app.MapGet("/products", async (IProductService service) =>
{
    return await service.GetAllProductsAsync();
})
.CacheOutput(policy => policy.Expire(TimeSpan.FromMinutes(5)));

// First request: 50ms (database query)
// Next requests: 0.5ms (from cache)
// = 100x faster!

Vary by Query String:

.CacheOutput(policy => policy
    .Expire(TimeSpan.FromMinutes(5))
    .SetVaryByQuery("category", "page"));

// Different cache for /products?category=1 vs category=2