It’s annoying to have ‘smart’ devices that can only interact with the manufacturer’s own website or smartphone app. Much better is for them to have an API which can hook into other home automation systems, either to bring everything together in one user interface or to support automation logic (like running the dishwasher when electricity is cheapest).
Miele have been exploring various options for home automation over the years and they’re in the process of moving from a peer-to-peer ZigBee architecture to a Cloud-based WiFi solution.
There’s been a smartphone app for a while (MIele@mobile) which clearly uses an API to connect to the Cloud-hosted back-end and now the “3rd Party API” is official released for other uses.
More info at https://www.miele.com/developer/index.html
There’s also some work ongoing to hook this into openHAB and MQTT; see https://community.openhab.org/t/cloud-based-miele-home-to-mqtt/52155