We need to first ask which country you are in, as the device selection does vary.
I don’t know of any coffee machine manufacturers who are providing smartthings-specific integration. Hopefully if there is one, someone will post about it.
There are a few integration options now, some easier than others.
- Switchbot robot button pusher (available in the US, UK, and Japan).
One of the easiest, but definitely not the least expensive, is to use the switchbot robot button pusher. This is essentially just a robot finger. You position it so it can push the existing button on any device. And using their “mini hub“ you can set up a cloud to cloud Integration with smartthings.
I use a number of these in my own home because I am quadriparetic. I have one on a single button mini blender, one to push the door open button on the microwave, one to push the eject button on the DVD player.
The device looks a little odd, but works quite well. It usually costs about $39 for the mini hub and $29 for each button pusher, but they do sometimes have sales.
I wrote a review of these for the forum, so here’s that with more details:
2020 Switchbot Review ( robot button pusher), integration through IFTTT or new V3 app
The biggest advantage to this is that it doesn’t affect the warranty of the coffee machine and it works with anything that has a button that can be pushed, including devices you already own. The biggest disadvantage is probably the cost.
- Alexa routines. If you are willing to buy a new coffee machine that works with Alexa, then you can use Alexa routines (not smartthings routines) to automate it. This feature is available in the US, Canada, the UK, and a number of European countries.
This is pretty straightforward now that Amazon has added “custom actions“ to their routines, which means you can activate an Alexa skill. If you just want it to activate at a specific time of day, you don’t even need to involve SmartThings. 
https://www.amazon.com/alexa-routines/
Some coffee maker manufacturers are even advertising this now as a feature of their machines. For example, Hamilton Beach does.
So there are now a number of coffee makers under $100 in the US can do this. The ones in Europe seem to be the more expensive models, but there are some.
This works very well, and notice that when using the Alexa routines you don’t even have to talk to the echo device, you can set it up on a schedule.
There’s even a way to get smartthings integration with this, but I’ve become reluctant to recommend it because it’s just been very glitchy for the last year or so. But here’s the FAQ on that if you’re interested.
FAQ: Can I trigger an Echo Action without Speaking to It?
- IFTTT. Some coffee machine makers have an IFTTT channel for their device. If they do, you can use that for Smartthings Integration. However, IFTTT used to be free to the end-user and now you have to pay a monthly fee if you have more than three rules. And again, you have to have a Coffee maker that has this feature or be willing to buy one. this is pretty easy to use, but long-term I have more concern about IFTTT removing features or raising prices than I do about Alexa, so that’s just something to be aware of.
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So those are three different approaches. If you already have a coffee maker that you love and that has pressable buttons, I would consider the Switchbot. It’s a good way of retrofitting existing dumb devices and it does have a smartthings Integration.
If you’re looking for a new machine and you already use Amazon echo, then I would definitely just get one that works with echo and use Alexa routines.
If you’re looking for a new machine and you prefer to use google home, then I would look for something with an IFTTT integration, but with the understanding that you might have to look for an alternative solution in a year or two if IFTTT changes their offerings.