---
title: Advanced topics
description: Instrumenting custom code, Sanitizing data, How the Agent works, Run Tests Locally. 
url: https://docs-v3-preview.elastic.dev/elastic/apm-agent-python/pull/2648/reference/advanced-topics
products:
  - APM Agent
  - APM Python Agent
applies_to:
  - Serverless Observability projects: Generally available
  - Elastic Stack: Generally available
  - Application Performance Monitoring Agent for Python: Generally available
---

# Advanced topics
- [Instrumenting custom code](https://docs-v3-preview.elastic.dev/elastic/apm-agent-python/pull/2648/reference/instrumenting-custom-code)
- [Sanitizing data](https://docs-v3-preview.elastic.dev/elastic/apm-agent-python/pull/2648/reference/sanitizing-data)
- [How the Agent works](https://docs-v3-preview.elastic.dev/elastic/apm-agent-python/pull/2648/reference/how-agent-works)
- [Run Tests Locally](https://docs-v3-preview.elastic.dev/elastic/apm-agent-python/pull/2648/reference/run-tests-locally)