Usually automation systems are always complex and the more functionality and flexibility you want from them the more complex they get. Like more things, I recommend using a RDBMS (relational database management system).
Not sure exactly what you are trying to do but it sounds like your want more flexibility and customization. As a rule I would use a relational database that supports triggers/stored procedures and try and keep as much logic and functionality within it. I recommend https://www.postgresql.org/.
You can use triggers, write some generic to send via notify or even specific triggers.
If you want to use python for your functions it's easy to add in.
Whenever I hear web interface I think of using Python Flask if you want to code yourself. Even simpler and less prone to bugs or errors use datatables editor and do the rest of the work in Postgres and maybe a simple dispatch script written in python that listens to notify statements. There is a small fee for Datables Editor but well worth your and others time. I doubt you would be disappointed. If you are alergic to PHP for some reason I would get an allergy shot and just use it. You barely touch it on the backend if you keep your UI simple. Every language/framework has issues. Use what works when it works.
There are drop in rest options as well like https://postgrest.org/ or https://www.graphile.org/postgraphile/ if you ever want more flexibility than datables gives you..
If you don't want to do notify/listen you can run a queue in a simple table in postgres or use rabbitmq or kafka as well.
There are really good complex/commercial applications that might work better but they are pricey and can be complex to operate and setup. If you are not familiar with using Postgres I would give that a try. It's been the best option for me in career.