Sorry, but I think this is really bad advice, it goes about it from the wrong direction. Saying "monolithic" or "services" like one is good and one is bad, or one is complicated and one is simple, is kind of silly.
For example... which is simpler, writing your own search indexing tool in ruby on rails, or installing solr as a service? MySQL is also service, for some reason people tend to forget that. Conversely, if your processes aren't yet resource hogs, why not just let them remain general purpose workers? If you are constantly fiddling with multiple services to make any changes to your app, then yes, you have probably made a bad choice somewhere. But a HAproxy/nginx/rails/memcache/mysql/solr stack is already six services, and not really so complicated to work with. When you write your own services, you should aspire to that level of simplicity.
At the end of the day, the shortest path will be wherever it will be. It's your job as a developer to weigh the pro's and cons on a case by case basis. The hard part is to test drive everything so that you can change it later, and constantly evaluate what choices each decision you make is removing from the table (painting yourself into a corner if you are not careful).
Another way of putting it: if you are picking your architecture before you begin, based on some kind of generalized principle, you are already over-engineering.
For example... which is simpler, writing your own search indexing tool in ruby on rails, or installing solr as a service? MySQL is also service, for some reason people tend to forget that. Conversely, if your processes aren't yet resource hogs, why not just let them remain general purpose workers? If you are constantly fiddling with multiple services to make any changes to your app, then yes, you have probably made a bad choice somewhere. But a HAproxy/nginx/rails/memcache/mysql/solr stack is already six services, and not really so complicated to work with. When you write your own services, you should aspire to that level of simplicity.
At the end of the day, the shortest path will be wherever it will be. It's your job as a developer to weigh the pro's and cons on a case by case basis. The hard part is to test drive everything so that you can change it later, and constantly evaluate what choices each decision you make is removing from the table (painting yourself into a corner if you are not careful).
Another way of putting it: if you are picking your architecture before you begin, based on some kind of generalized principle, you are already over-engineering.