diff --git a/Dockerfile b/Dockerfile
index a01aae254..14d606c0a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,7 +14,7 @@ ENV TALK_PORT 5000
 EXPOSE 5000
 
 # Install app dependencies
-COPY package.json /usr/src/app/
+COPY package.json yarn.lock /usr/src/app/
 RUN yarn install --production
 
 # Bundle app source
diff --git a/client/coral-admin/src/actions/auth.js b/client/coral-admin/src/actions/auth.js
index 8bc0d4e4c..bdb101362 100644
--- a/client/coral-admin/src/actions/auth.js
+++ b/client/coral-admin/src/actions/auth.js
@@ -16,7 +16,7 @@ export const checkLogin = () => dispatch => {
     })
     .catch(error => {
       console.error(error);
-      dispatch(checkLoginFailure(`${error.message}`));
+      dispatch(checkLoginFailure(`${error.translation_key}`));
     });
 };
 
diff --git a/client/coral-admin/src/actions/install.js b/client/coral-admin/src/actions/install.js
index a74a1929f..c1d05d253 100644
--- a/client/coral-admin/src/actions/install.js
+++ b/client/coral-admin/src/actions/install.js
@@ -81,7 +81,7 @@ export const submitUser = () => (dispatch, getState) => {
       })
       .catch(error => {
         console.error(error);
-        dispatch(installFailure(`${error.message}`));
+        dispatch(installFailure(`${error.translation_key}`));
       });
   });
 };
@@ -104,6 +104,6 @@ export const checkInstall = next => dispatch => {
     })
     .catch(error => {
       console.error(error);
-      dispatch(checkInstallFailure(`${error.message}`));
+      dispatch(checkInstallFailure(`${error.translation_key}`));
     });
 };
diff --git a/client/coral-embed-stream/src/Comment.js b/client/coral-embed-stream/src/Comment.js
index 034c44f6a..9d679473e 100644
--- a/client/coral-embed-stream/src/Comment.js
+++ b/client/coral-embed-stream/src/Comment.js
@@ -142,7 +142,6 @@ class Comment extends React.Component {
           ? <ReplyBox
               commentPostedHandler={() => {
                 setActiveReplyBox('');
-                refetch();
               }}
               setActiveReplyBox={setActiveReplyBox}
               parentId={parentId || comment.id}
diff --git a/client/coral-embed-stream/src/Embed.js b/client/coral-embed-stream/src/Embed.js
index 8b420836e..a7c4dcb38 100644
--- a/client/coral-embed-stream/src/Embed.js
+++ b/client/coral-embed-stream/src/Embed.js
@@ -128,7 +128,6 @@ class Embed extends Component {
                    {
                      user
                      ? <CommentBox
-                        commentPostedHandler={refetch}
                         addNotification={this.props.addNotification}
                         postItem={this.props.postItem}
                         appendItemArray={this.props.appendItemArray}
diff --git a/client/coral-framework/actions/auth.js b/client/coral-framework/actions/auth.js
index 8618cf1d3..4a12245eb 100644
--- a/client/coral-framework/actions/auth.js
+++ b/client/coral-framework/actions/auth.js
@@ -123,7 +123,7 @@ export const fetchSignUp = (formData, redirectUri) => (dispatch) => {
       dispatch(signUpSuccess(user));
     })
     .catch(error => {
-      dispatch(signUpFailure(lang.t(`error.${error.translation_key}`)));
+      dispatch(signUpFailure(lang.t(`error.${error.message}`)));
     });
 };
 
@@ -177,7 +177,7 @@ export const checkLogin = () => dispatch => {
     })
     .catch(error => {
       console.error(error);
-      dispatch(checkLoginFailure(`${error.message}`));
+      dispatch(checkLoginFailure(`${error.translation_key}`));
     });
 };
 
diff --git a/client/coral-framework/components/SuspendedAccount.js b/client/coral-framework/components/SuspendedAccount.js
index 00adc9952..446169b37 100644
--- a/client/coral-framework/components/SuspendedAccount.js
+++ b/client/coral-framework/components/SuspendedAccount.js
@@ -26,7 +26,7 @@ class SuspendedAccount extends Component {
       editName(username)
         .then(() => location.reload())
         .catch((error) => {
-          this.setState({alert: lang.t(`error.${error.message}`)});
+          this.setState({alert: lang.t(`error.${error.translation_key}`)});
         });
     } else {
       this.setState({alert: lang.t('editName.error')});
diff --git a/client/coral-framework/graphql/mutations/index.js b/client/coral-framework/graphql/mutations/index.js
index 40ca0a7a3..a9d08da85 100644
--- a/client/coral-framework/graphql/mutations/index.js
+++ b/client/coral-framework/graphql/mutations/index.js
@@ -10,16 +10,72 @@ export const postComment = graphql(POST_COMMENT, {
   options: () => ({
     fragments: commentView
   }),
-  props: ({mutate}) => ({
-    postItem: ({asset_id, body, parent_id} /* , type */ ) => {
-      return mutate({
+  props: ({ownProps, mutate}) => ({
+    postItem: ({asset_id, body, parent_id}) =>
+      mutate({
         variables: {
           asset_id,
           body,
           parent_id
+        },
+        optimisticResponse: {
+          createComment: {
+            comment: {
+              user: {
+                id: ownProps.auth.user.id,
+                name: ownProps.auth.user.username
+              },
+              created_at: new Date().toISOString(),
+              body,
+              parent_id,
+              asset_id,
+              action_summaries: [],
+              tags: [],
+              status: null,
+              id: `${Date.now()}_temp_id`
+            }
+          }
+        },
+        updateQueries: {
+          AssetQuery: (oldData, {mutationResult:{data:{createComment:{comment}}}}) => {
+
+            if (oldData.asset.moderation === 'PRE') {
+              return oldData;
+            }
+
+            let updatedAsset;
+
+            // If posting a reply
+            if (parent_id) {
+              updatedAsset = {
+                ...oldData,
+                asset: {
+                  ...oldData.asset,
+                  comments: oldData.asset.comments.map((oldComment) => {
+                    return oldComment.id === parent_id
+                    ? {...oldComment, replies: [...oldComment.replies, comment]}
+                    : oldComment;
+                  })
+                }
+              };
+            } else {
+
+              // If posting a top-level comment
+              updatedAsset = {
+                ...oldData,
+                asset: {
+                  ...oldData.asset,
+                  commentCount: oldData.asset.commentCount + 1,
+                  comments: [comment, ...oldData.asset.comments]
+                }
+              };
+            }
+
+            return updatedAsset;
+          }
         }
-      });
-    }}),
+      })
+  }),
 });
 
 export const postLike = graphql(POST_LIKE, {
diff --git a/client/coral-framework/graphql/mutations/postComment.graphql b/client/coral-framework/graphql/mutations/postComment.graphql
index 6ce46eaa8..110ab4b4e 100644
--- a/client/coral-framework/graphql/mutations/postComment.graphql
+++ b/client/coral-framework/graphql/mutations/postComment.graphql
@@ -4,6 +4,10 @@ mutation CreateComment ($asset_id: ID!, $parent_id: ID, $body: String!) {
     createComment(asset_id:$asset_id, parent_id:$parent_id, body:$body) {
         comment {
           ...commentView
+          replyCount
+          replies {
+              ...commentView
+          }
         }
         errors {
           translation_key
diff --git a/package.json b/package.json
index 09ce50aa9..70b0e17b1 100644
--- a/package.json
+++ b/package.json
@@ -49,7 +49,6 @@
   },
   "homepage": "https://github.com/coralproject/talk#readme",
   "dependencies": {
-    "apollo-client": "^0.8.3",
     "bcrypt": "^0.8.7",
     "body-parser": "^1.15.2",
     "cli-table": "^0.3.1",
@@ -66,7 +65,6 @@
     "graphql": "^0.8.2",
     "graphql-errors": "^2.1.0",
     "graphql-server-express": "^0.5.0",
-    "graphql-tag": "^1.2.3",
     "graphql-tools": "^0.9.0",
     "helmet": "^3.1.0",
     "inquirer": "^3.0.1",
@@ -88,6 +86,7 @@
     "uuid": "^2.0.3"
   },
   "devDependencies": {
+    "apollo-client": "^0.8.3",
     "autoprefixer": "^6.5.2",
     "babel-core": "^6.21.0",
     "babel-eslint": "^7.1.0",
@@ -122,6 +121,7 @@
     "exports-loader": "^0.6.3",
     "fetch-mock": "^5.5.0",
     "graphql-docs": "^0.2.0",
+    "graphql-tag": "^1.2.3",
     "hammerjs": "^2.0.8",
     "ignore-styles": "^5.0.1",
     "immutable": "^3.8.1",
diff --git a/routes/api/account/index.js b/routes/api/account/index.js
index 4eab8b920..ee10636bf 100644
--- a/routes/api/account/index.js
+++ b/routes/api/account/index.js
@@ -102,15 +102,13 @@ router.put('/password/reset', (req, res, next) => {
 
   UsersService
     .verifyPasswordResetToken(token)
-    .then(user => {
+    .then((user) => {
       return UsersService.changePassword(user.id, password);
     })
     .then(() => {
       res.status(204).end();
     })
-    .catch(error => {
-      console.error(error);
-
+    .catch(() => {
       next(authorization.ErrNotAuthorized);
     });
 });
@@ -121,12 +119,8 @@ router.put('/username', authorization.needed(), (req, res, next) => {
     .then(() => {
       res.status(204).end();
     })
-    .catch(error => {
-      if (error.code === 11000) {
-        next(errors.ErrUsernameTaken);
-      } else {
-        next(error);
-      }
+    .catch((err) => {
+      next(err);
     });
 });
 
diff --git a/routes/api/assets/index.js b/routes/api/assets/index.js
index 0b6762de8..3bb3ef778 100644
--- a/routes/api/assets/index.js
+++ b/routes/api/assets/index.js
@@ -79,7 +79,8 @@ router.get('/:asset_id', (req, res, next) => {
     .findById(req.params.asset_id)
     .then((asset) => {
       if (!asset) {
-        return res.status(404).end();
+        res.status(404).end();
+        return;
       }
 
       res.json(asset);
@@ -97,15 +98,17 @@ router.post('/:asset_id/scrape', (req, res, next) => {
     .findById(req.params.asset_id)
     .then((asset) => {
       if (!asset) {
-        return res.status(404).end();
+        res.status(404).end();
+        return;
       }
 
-      return scraper.create(asset);
-    })
-    .then((job) => {
+      return scraper
+        .create(asset)
+        .then((job) => {
 
-      // Send the job back for monitoring.
-      res.status(201).json(job);
+          // Send the job back for monitoring.
+          res.status(201).json(job);
+        });
     })
     .catch((err) => {
       next(err);
@@ -117,8 +120,12 @@ router.put('/:asset_id/settings', (req, res, next) => {
   // Override the settings for the asset.
   AssetsService
     .overrideSettings(req.params.asset_id, req.body)
-    .then(() => res.status(204).end())
-    .catch((err) => next(err));
+    .then(() => {
+      res.status(204).end();
+    })
+    .catch((err) => {
+      next(err);
+    });
 });
 
 router.put('/:asset_id/status', (req, res, next) => {
diff --git a/routes/api/settings/index.js b/routes/api/settings/index.js
index f1a5fe9f7..5c4b03568 100644
--- a/routes/api/settings/index.js
+++ b/routes/api/settings/index.js
@@ -5,7 +5,8 @@ const router = express.Router();
 
 router.get('/', (req, res, next) => {
   SettingsService
-    .retrieve().then((settings) => {
+    .retrieve()
+    .then((settings) => {
       res.json(settings);
     })
     .catch((err) => {
diff --git a/routes/api/setup/index.js b/routes/api/setup/index.js
index e325769cd..dfddc64d9 100644
--- a/routes/api/setup/index.js
+++ b/routes/api/setup/index.js
@@ -43,7 +43,7 @@ router.post('/', (req, res, next) => {
       res.status(204).end();
     })
     .catch((err) => {
-      return next(err);
+      next(err);
     });
 
 });
diff --git a/routes/api/users/index.js b/routes/api/users/index.js
index 4182beb49..2af6bc2ee 100644
--- a/routes/api/users/index.js
+++ b/routes/api/users/index.js
@@ -136,7 +136,7 @@ router.post('/', (req, res, next) => {
           res.status(201).json(user);
         });
     })
-    .catch(err => {
+    .catch((err) => {
       next(err);
     });
 });
@@ -152,7 +152,7 @@ router.post('/:user_id/actions', authorization.needed(), (req, res, next) => {
     .then((action) => {
 
       // Set the user status to "pending" for review by moderators
-      if (action_type.slice(0, 4) === 'FLAG') {
+      if (action_type === 'FLAG') {
         return UsersService.setStatus(req.params.user_id, 'PENDING')
           .then(() => action);
       } else {
@@ -163,7 +163,6 @@ router.post('/:user_id/actions', authorization.needed(), (req, res, next) => {
       res.status(201).json(action);
     })
     .catch((err) => {
-      console.log('Error', err);
       next(err);
     });
 });
diff --git a/services/users.js b/services/users.js
index b09a7d399..cf3a0063d 100644
--- a/services/users.js
+++ b/services/users.js
@@ -686,9 +686,20 @@ module.exports = class UsersService {
         canEditName: false,
         status: 'PENDING'
       }
-    }).then((result) => {
-      return result.nModified > 0 ? result :
-        Promise.reject(errors.ErrPermissionUpdateUsername);
+    })
+    .then((result) => {
+      if (result.nModified <= 0) {
+        return Promise.reject(errors.ErrPermissionUpdateUsername);
+      }
+
+      return result;
+    })
+    .catch((err) => {
+      if (err.code === 11000) {
+        throw errors.ErrUsernameTaken;
+      }
+
+      throw err;
     });
   }
 };