Talend is an ETL tool: Extract data from a data source (file, database, API), Transform it, and Load it into another data source (file, database, API), all in a pipeline. Talend's happy path is the same as Unix shell's happy path: A pipeline of data with no side-effects and no globals. Try to deviate from that and you hit walls, some more climbable than others.
For example, Talend absolutely will not allow you to re-combine a pipeline you've split; you can combine two separate data sources, and you can split to two separate sinks, but you absolutely cannot go from one pipeline to two pipelines back down to one.
The saving grace is that Talend is fundamentally a GUI for writing Java. You can see the Java it's writing, and you can add your own Java in a few ways, from adding jar files to just plopping a pipeline component that allows you to insert your own Java into the big God Method that the rest of your pipeline helping to form. Be sure you know how scoping works if you do that.
In extremis, you can "use Talend" in that you use the Talend GUI as an Eclipse IDE to write the one pipeline component that does everything because it contains all of the useful Java code. You can use it the way I often used it, to take care of some tedious "plumbing" code to route the pieces of data created by the hand-written component to their respective outputs, including handling some minor output conditioning that can be done in a stateless fashion. It can even be used as it was intended to be used, as odd as that sounds.
Talend is an ETL tool: Extract data from a data source (file, database, API), Transform it, and Load it into another data source (file, database, API), all in a pipeline. Talend's happy path is the same as Unix shell's happy path: A pipeline of data with no side-effects and no globals. Try to deviate from that and you hit walls, some more climbable than others.
For example, Talend absolutely will not allow you to re-combine a pipeline you've split; you can combine two separate data sources, and you can split to two separate sinks, but you absolutely cannot go from one pipeline to two pipelines back down to one.
The saving grace is that Talend is fundamentally a GUI for writing Java. You can see the Java it's writing, and you can add your own Java in a few ways, from adding jar files to just plopping a pipeline component that allows you to insert your own Java into the big God Method that the rest of your pipeline helping to form. Be sure you know how scoping works if you do that.
In extremis, you can "use Talend" in that you use the Talend GUI as an Eclipse IDE to write the one pipeline component that does everything because it contains all of the useful Java code. You can use it the way I often used it, to take care of some tedious "plumbing" code to route the pieces of data created by the hand-written component to their respective outputs, including handling some minor output conditioning that can be done in a stateless fashion. It can even be used as it was intended to be used, as odd as that sounds.