+++
pre = "<b>5. </b>"
title = "Dev Manual"
weight = 5
chapter = true
+++

ElasticJob provides dozens of SPI based extensions. 
it is very convenient to customize the functions for developers.

This chapter lists all SPI extensions of ElasticJob.
If there is no special requirement, users can use the built-in implementation provided by ElasticJob; 
advanced users can refer to the interfaces for customized implementation.

ElasticJob community welcomes developers to feed back their implementations to the [open-source community](https://github.com/apache/shardingsphere-elasticjob/pulls), 
so that more users can benefit from it.
