.Net Performance Improvement

1️⃣ Optimize Code & Algorithms

• Choose the right data structures.

  • Use List<T> instead of ArrayList, Dictionary<TKey,TValue> for lookups.

• Reduce unnecessary work.

  • Avoid repeated calculations inside loops.

• Use async/await for I/O

  • Let the thread handle other requests while waiting for database or network.

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2️⃣ Manage Memory Smartly

• Dispose objects implementing IDisposable (e.g., SqlConnection, FileStream) with using blocks.

• Avoid memory leaks.

  • Unsubscribe from events.

  • Remove references you no longer need so the Garbage Collector (GC) can clean them.

• Use object pooling (e.g., ArrayPool<T>) for frequently used buffers.

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3️⃣ Improve Database Access

• Use async EF Core methods (ToListAsync, etc.).

• Optimize queries: fetch only what you need (SELECT specific columns).

• Cache frequently used data (e.g., with MemoryCache, Redis).

• Use connection pooling (default in ADO.NET).

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4️⃣ Caching Strategies

• In-memory cache for small/fast-changing data:

  services.AddMemoryCache();
  

• Distributed cache like Redis for web farms or microservices.

• Cache heavy results (like product lists) to reduce repeated DB hits.

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5️⃣ Configure the Garbage Collector

• Prefer Server GC for web/multi-core servers (<gcServer enabled="true"/> in runtimeconfig.json).

• Minimize large object heap allocations (avoid repeatedly creating big arrays/strings).

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6️⃣ Use Asynchronous & Parallel Processing

• Use Task.Run, Parallel.ForEach, or TPL Dataflow when tasks can run in parallel.

• Avoid blocking calls like .Result or .Wait() on async methods.

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7️⃣ Tune ASP.NET Core Settings

• Response Compression middleware for smaller responses.

• Kestrel tuning: increase max concurrent connections if needed.

• Enable HTTP/2 for faster multiplexed requests.

• Use IHostedService for background work instead of blocking controllers.

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8️⃣ Minimize Serialization Overhead

• Use System.Text.Json (faster than Newtonsoft.Json).

• Reuse JsonSerializerOptions instances.

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9️⃣ Frontend / Network Tips (for web apps)

• Enable gzip/brotli compression.

• Use CDN for static files.

• Cache static content with proper headers.

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🔟 Profiling & Monitoring

• Use tools like:

  • dotnet-trace / dotnet-counters (built-in).

  • PerfView, JetBrains Rider profiler, Visual Studio Profiler.

  • Application Insights or Prometheus/Grafana in production.

• Identify slow methods, memory leaks, or high CPU usage.

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1️⃣1️⃣ Deployment & Build

• Use Release build, not Debug.

• Enable ReadyToRun or Crossgen to precompile.

• Consider Ahead-of-Time (AOT) for .NET 8+ if startup time is critical.

• Publish as self-contained to control runtime versions.

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✅ Quick Checklist

Area	Tip
Code	Minimize loops, use async I/O
Memory	Dispose, avoid leaks, object pool
Database	Optimize queries, cache results
Caching	MemoryCache or Redis
Web/API	Response compression, HTTP/2, Kestrel tuning
Profiling	Use dotnet-counters, Visual Studio, Application Insights

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🏁 Key Takeaway

Performance comes from:

1. Efficient code (algorithms + async/await)

2. Optimized resource usage (memory, database, network)

3. Monitoring and profiling to find real bottlenecks.

Focus first on measuring (profiling), then apply these improvements where they matter most.