As an example, what I do with n8n to hook services together:

• We use Zello in firefighting to document the incident with short verbal notes or take pictures. Voice gets transcribed, sent to MQTT for dashboards, taken by Telegraf to influx. Pictures and mp3s get downloaded from zello, put into minio, linked back with the metadata and also sent to influx. Finally all is displayed on a Dashboard. Zello, Minio, MQTT, influx all flied together with n8n.
• Another one is the appsmith app for equipment maintenance. We need reports and appsmith is bad at that. n8n queries the Source pgsql, formats it to JSON, sends it to an online service to generate a PDF (with a template), downloads the PDF and puts it into Nextcloud.

There is more, but just as an example. Quite easy in n8n, because many integrations are preconfigured (e.g. Nextcloud), but also plain REST API if necessary (zello).