Hello Max, let me add my 50 cents here. It’s currently not possible to connect these systems directly with GoodData - as far as I know these system do not expose data store for analytics to access.
However it is not difficult to ingest the data to data warehouse and use analytics on top of it. In our case we are working with Zendesk and Amplitude.
We use Snowflake as data warehouse (but can be quite easily switched to other DWH).
In case of Zendesk we use Meltano as extract tool from API (initial load may need bit more time due to ZD API limitations), ingest the data into DWH and use it within GoodData analytics (combined with other data like SFDC) - the setup is very similar to our
SFDC demo.
In case of Amplitude - the tool offers native data export to Snowflake (and other destinations) so we use it and again use the data for analytics (and again combined with other sources).
Let me know in case you’d want more details.