It is possible to build custom Ataccama Java jars using Maven, but we do not support building customer’s jars and do not have tutorials to achieve it.
There is a built-in documentation in Eclipse about Custom Steps in Java and Custom Function in Java that would be useful. Please, navigate to Help -> Help Contents -> Ataccama Data Quality Center (version x.x.x) -> Advanced Usage.
In addition, we would like to mention that all custom functionality will not be supported.
Please, let us know if you need any further information.