sucker_punch | Sucker Punch is a Ruby asynchronous processing library | Application Framework library

Is uglifier and sass-rails needed?

If you don't use sass on your project you can remove sass-rails. But I see you have font-awesome-sass gem.

Uglifier is used only when compiling assets so your css and js files are smaller.

The app has 200 tables. Will reducing the number of models and using .pluck on queries help reduce RAM use?

Rails autoloads your code, but I doubt the number of models has a significant impact on the ram usage. On the other hand, when you read a record from the database, rails has to create an ActiveRecord object on memory, if you have a table with hundreds of records and you just load all of them at once (User.all.to_a or User.all.each) it will require a lot of ram but only on that specific moment. Usually pluck is a good way to use less ram since you only fetch an array of the values you want and not complete AR objects when you don't need them.

Will removing js dependencies such as mapbox and other css also reduce RAM use?

I don't think so, js dependencies are used during assets compilation.

A good trick to free some ram if you use multiple threads is to use jemalloc instead of the standard malloc for memory allocation https://www.youtube.com/watch?v=4_yxbh9Enoc

Another thing you can do is to only load the rails modules you actually use. On your config/application.rb file you'll see a line like this require 'rails/all' that loads all rails features https://github.com/rails/rails/blob/master/railties/lib/rails/all.rb

You can change that line to only import the features you want, like if you don't use action_cable or active_job you can just import the rest.

Another thing you can do is remove gems related to third party js and css like bootstrap, font-awesome, jquery and use yarn to handle dependencies of js and css. You may lose some view helpers provided by those gems though.

I ended up solving this question by adding an error rescue around the RETS query like this:

I'm familiar with I18n within the application, but not so much in mailers. Remember that the mailer is being sent outside the request (ActiveJob), so it has no knowledge of anything that happened there. It looks like you haven't done anything to tell the mailer that it should be sending in a specific locale....

OK maybe this has the answer for you (and me!) https://niallburkley.com/blog/localize-rails-emails/