diff --git a/lib/blueprinter/formatters/date_time_formatter.rb b/lib/blueprinter/formatters/date_time_formatter.rb
index db358a13..e4eb5e9c 100644
--- a/lib/blueprinter/formatters/date_time_formatter.rb
+++ b/lib/blueprinter/formatters/date_time_formatter.rb
@@ -5,26 +5,22 @@ class DateTimeFormatter
     def format(value, options)
       return value if value.nil?
 
-      field_format = options[:datetime_format]
-      if value.respond_to?(:strftime)
-        value = format_datetime(value, field_format)
-      elsif field_format
-        raise InvalidDateTimeFormatterError, 'Cannot format invalid DateTime object'
-      end
+      field_format = options[:datetime_format] || Blueprinter.configuration.datetime_format
+      return value if field_format.nil?
+ 
+      return format_datetime(value, field_format) if value.respond_to?(:strftime)
+      raise InvalidDateTimeFormatterError, 'Cannot format invalid DateTime object' if options[:datetime_format]
       value
     end
 
     private
 
     def format_datetime(value, field_format)
-      format = field_format || Blueprinter.configuration.datetime_format
-
-      case format
-      when NilClass then value
-      when Proc then format.call(value)
-      when String then value.strftime(format)
+      case field_format
+      when Proc then field_format.call(value)
+      when String then value.strftime(field_format)
       else
-        raise InvalidDateTimeFormatterError, 'Cannot format DateTime object with invalid formatter: #{format.class}'
+        raise InvalidDateTimeFormatterError, 'Cannot format DateTime object with invalid formatter: #{field_format.class}'
       end
     end
   end
diff --git a/lib/blueprinter/view_collection.rb b/lib/blueprinter/view_collection.rb
index 56be69ac..c23eb2d2 100644
--- a/lib/blueprinter/view_collection.rb
+++ b/lib/blueprinter/view_collection.rb
@@ -8,6 +8,7 @@ def initialize
         default: View.new(:default)
       }
       @sort_by_definition = Blueprinter.configuration.sort_fields_by.eql?(:definition)
+      @fields_for = {}
     end
 
     def inherit(view_collection)
@@ -21,12 +22,15 @@ def has_view?(view_name)
     end
 
     def fields_for(view_name)
-      return identifier_fields if view_name == :identifier
-
-      fields, excluded_fields = sortable_fields(view_name)
-      sorted_fields = sort_by_definition ? sort_by_def(view_name, fields) : fields.values.sort_by(&:name)
-
-      (identifier_fields + sorted_fields).reject { |field| excluded_fields.include?(field.name) }
+      @fields_for[view_name] ||=
+        if view_name == :identifier
+          identifier_fields
+        else
+          fields, excluded_fields = sortable_fields(view_name)
+          sorted_fields = sort_by_definition ? sort_by_def(view_name, fields) : fields.values.sort_by(&:name)
+
+          (identifier_fields + sorted_fields).reject { |field| excluded_fields.include?(field.name) }
+        end
     end
 
     def transformers(view_name)