# Application Code

This section covers C# development within Umbraco. Topics include custom controllers, routing, dependency injection, subscribing to notifications, Examine search, and common application code pitfalls.

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><strong>Backend and Custom Logic</strong></td><td>Build custom controllers, configure routing, use dependency injection, subscribe to notifications, and access Umbraco services.</td><td><a href="/pages/r7MaBOvKQWZ0AG4lYUij">/pages/r7MaBOvKQWZ0AG4lYUij</a></td></tr><tr><td><strong>Searching with Examine</strong></td><td>Index and search Umbraco content and media using Examine, a Lucene-based search library with Umbraco-specific APIs.</td><td><a href="/pages/76324ybqDztWR8XOF0id">/pages/76324ybqDztWR8XOF0id</a></td></tr><tr><td><strong>Common Pitfalls</strong></td><td>Learn about common mistakes in Umbraco application code and how to avoid them.</td><td><a href="/pages/Cgwe7QnQmlbhDUUNDjZW">/pages/Cgwe7QnQmlbhDUUNDjZW</a></td></tr></tbody></table>


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