diff --git a/lms/djangoapps/django_comment_client/forum/views.py b/lms/djangoapps/django_comment_client/forum/views.py
index 5f94eade77..58b6d30182 100644
--- a/lms/djangoapps/django_comment_client/forum/views.py
+++ b/lms/djangoapps/django_comment_client/forum/views.py
@@ -112,7 +112,7 @@ def get_threads(request, course_id, discussion_id=None):
     default_query_params = {
         'page': 1,
         'per_page': THREADS_PER_PAGE,
-        'sort_key': 'activity',
+        'sort_key': 'date',
         'sort_order': 'desc',
         'text': '',
         'tags': '',
@@ -120,6 +120,18 @@ def get_threads(request, course_id, discussion_id=None):
         'course_id': course_id,
     }
 
+    if not request.GET.get('sort_key'):
+        # If the user did not select a sort key, use their last used sort key
+        user = cc.User.from_django_user(request.user)
+        user.retrieve()
+        # TODO: After the comment service is updated this can just be user.default_sort_key because the service returns the default value
+        default_query_params['sort_key'] = user.get('default_sort_key') or default_query_params['sort_key']
+    else:
+        # If the user clicked a sort key, update their default sort key
+        user = cc.User.from_django_user(request.user)
+        user.default_sort_key = request.GET.get('sort_key')
+        user.save()
+
     query_params = merge_dict(default_query_params,
                               strip_none(extract(request.GET, ['page', 'sort_key', 'sort_order', 'text', 'tags'])))
 
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 5cd28d24d9..5c8a8bf3d6 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -432,7 +432,7 @@ main_vendor_js = [
   'js/vendor/jquery.qtip.min.js',
 ]
 
-discussion_js = glob2.glob(PROJECT_ROOT / 'static/coffee/src/discussion/*.coffee')
+discussion_js = sorted(glob2.glob(PROJECT_ROOT / 'static/coffee/src/discussion/*.coffee'))
 
 # Load javascript from all of the available xmodules, and
 # prep it for use in pipeline js
@@ -500,10 +500,10 @@ PIPELINE_JS = {
         'source_filenames': [
             pth.replace(COMMON_ROOT / 'static/', '')
             for pth
-            in glob2.glob(COMMON_ROOT / 'static/coffee/src/**/*.coffee')
+            in sorted(glob2.glob(COMMON_ROOT / 'static/coffee/src/**/*.coffee'))
         ] + [
             pth.replace(PROJECT_ROOT / 'static/', '')
-            for pth in glob2.glob(PROJECT_ROOT / 'static/coffee/src/**/*.coffee')\
+            for pth in sorted(glob2.glob(PROJECT_ROOT / 'static/coffee/src/**/*.coffee'))\
             if pth not in courseware_only_js and pth not in discussion_js
         ] + [
             'js/form.ext.js',
diff --git a/lms/lib/comment_client/user.py b/lms/lib/comment_client/user.py
index ae4abf91b7..eea6fda407 100644
--- a/lms/lib/comment_client/user.py
+++ b/lms/lib/comment_client/user.py
@@ -8,10 +8,10 @@ class User(models.Model):
     accessible_fields = ['username', 'email', 'follower_ids', 'upvoted_ids', 'downvoted_ids',
                          'id', 'external_id', 'subscribed_user_ids', 'children', 'course_id',
                          'subscribed_thread_ids', 'subscribed_commentable_ids',
-                         'threads_count', 'comments_count',
+                         'threads_count', 'comments_count', 'default_sort_key'
                         ]
 
-    updatable_fields = ['username', 'external_id', 'email']
+    updatable_fields = ['username', 'external_id', 'email', 'default_sort_key']
     initializable_fields = updatable_fields
 
     base_url = "{prefix}/users".format(prefix=settings.PREFIX)
diff --git a/lms/static/sass/_discussion.scss b/lms/static/sass/_discussion.scss
index 755ef91289..b00dc069f1 100644
--- a/lms/static/sass/_discussion.scss
+++ b/lms/static/sass/_discussion.scss
@@ -506,7 +506,8 @@ $tag-text-color: #5b614f;
       font-size: inherit;
       font-weight: bold;
       margin-left: 1%;
-      padding-top: 9px;
+      padding-top: 4px;
+      padding-bottom: 2px;
       text-decoration: none;
     }
 
diff --git a/lms/templates/discussion/_sort.html b/lms/templates/discussion/_sort.html
index 7ba10eab7b..99ba58f7c8 100644
--- a/lms/templates/discussion/_sort.html
+++ b/lms/templates/discussion/_sort.html
@@ -31,9 +31,9 @@
 
 <div class="discussion-sort local">
   <span class="discussion-label">Sort by:</span>
-  ${link_to_sort('activity', 'top')}
-  
   ${link_to_sort('date', 'date')}
+
+  ${link_to_sort('activity', 'top')}
   
   ${link_to_sort('votes', 'votes')}