I have Schlage Sense integrated into Apple HomeKit. You can have a code any where from 4-8 digits long and will set off an alarm if too many incorrect entries are tried. So I wouldn’t worry about someone brute force guessing your code.

 To lock and unlock the front door I can use a physical key, the keypad, the use the default Schlage app, the Home app on my iPhone or ask Siri. It can also be used with a geofence and HomeKit automations to automatically lock/unlock.  

DIY set up was a breeze and only took 10 minutes. It requires AA batteries which in the 3 years we have had it have only replaced I think 3 times. They were cheapish batteries so you might get longer from expensive batteries.

you can set up a schedule for particular codes which is handy for the likes of a cleaner who would come at a regular time and date. You can store up to 30 codes. 

I like the security and peace of mind that HomeKit provides and have had no issues. My only complaint is that there is no way to lock the door in such a way from the inside to fully prevent external entry even with a key or code. I’d quite like to be able to do this when home alone at night for even more peace of mind. I guess I could just install a manual security bolt or similar.