diff --git a/backend/src/activitypub/ActivityPub.js b/backend/src/activitypub/ActivityPub.js
index 12671f330..cd16f620e 100644
--- a/backend/src/activitypub/ActivityPub.js
+++ b/backend/src/activitypub/ActivityPub.js
@@ -35,8 +35,8 @@ export default class ActivityPub {
 
   handleFollowActivity(activity) {
     debug(`inside FOLLOW ${activity.actor}`)
-    let toActorName = extractNameFromId(activity.object)
-    let fromDomain = extractDomainFromUrl(activity.actor)
+    const toActorName = extractNameFromId(activity.object)
+    const fromDomain = extractDomainFromUrl(activity.actor)
     const dataSource = this.dataSource
 
     return new Promise((resolve, reject) => {
@@ -53,7 +53,7 @@ export default class ActivityPub {
           toActorObject = JSON.parse(toActorObject)
           await this.dataSource.addSharedInboxEndpoint(toActorObject.endpoints.sharedInbox)
 
-          let followersCollectionPage = await this.dataSource.getFollowersCollectionPage(
+          const followersCollectionPage = await this.dataSource.getFollowersCollectionPage(
             activity.object,
           )
 
@@ -222,6 +222,7 @@ export default class ActivityPub {
       })
     }
   }
+
   async trySend(activity, fromName, host, url, tries = 5) {
     try {
       return await signAndSend(activity, fromName, host, url)
diff --git a/backend/src/activitypub/Collections.js b/backend/src/activitypub/Collections.js
index 641db596a..4040468cf 100644
--- a/backend/src/activitypub/Collections.js
+++ b/backend/src/activitypub/Collections.js
@@ -2,6 +2,7 @@ export default class Collections {
   constructor(dataSource) {
     this.dataSource = dataSource
   }
+
   getFollowersCollection(actorId) {
     return this.dataSource.getFollowersCollection(actorId)
   }
diff --git a/backend/src/activitypub/NitroDataSource.js b/backend/src/activitypub/NitroDataSource.js
index 0900bed6c..dfdbf6c14 100644
--- a/backend/src/activitypub/NitroDataSource.js
+++ b/backend/src/activitypub/NitroDataSource.js
@@ -303,6 +303,7 @@ export default class NitroDataSource {
       }),
     )
   }
+
   async saveFollowingCollectionPage(followingCollection, onlyNewestItem = true) {
     debug('inside saveFollowers')
     let orderedItems = followingCollection.orderedItems
@@ -470,6 +471,7 @@ export default class NitroDataSource {
     throwErrorIfApolloErrorOccurred(result)
     return result.data.SharedInboxEnpoint
   }
+
   async addSharedInboxEndpoint(uri) {
     try {
       const result = await this.client.mutate({
diff --git a/backend/src/activitypub/security/index.js b/backend/src/activitypub/security/index.js
index 9b48b7ed9..05642ed26 100644
--- a/backend/src/activitypub/security/index.js
+++ b/backend/src/activitypub/security/index.js
@@ -97,7 +97,7 @@ export function verifySignature(url, headers) {
 // private: signing
 function constructSigningString(url, headers) {
   const urlObj = new URL(url)
-  let signingString = `(request-target): post ${urlObj.pathname}${
+  const signingString = `(request-target): post ${urlObj.pathname}${
     urlObj.search !== '' ? urlObj.search : ''
   }`
   return Object.keys(headers).reduce((result, key) => {
diff --git a/backend/src/activitypub/utils/index.js b/backend/src/activitypub/utils/index.js
index 3927f4056..5f26c635f 100644
--- a/backend/src/activitypub/utils/index.js
+++ b/backend/src/activitypub/utils/index.js
@@ -40,70 +40,72 @@ export function signAndSend(activity, fromName, targetDomain, url) {
   // fix for development: replace with http
   url = url.indexOf('localhost') > -1 ? url.replace('https', 'http') : url
   debug(`passhprase = ${CONFIG.PRIVATE_KEY_PASSPHRASE}`)
-  return new Promise(async (resolve, reject) => {
+  return new Promise((resolve, reject) => {
     debug('inside signAndSend')
     // get the private key
-    const result = await activityPub.dataSource.client.query({
-      query: gql`
+    activityPub.dataSource.client
+      .query({
+        query: gql`
           query {
               User(slug: "${fromName}") {
                   privateKey
               }
           }
       `,
-    })
+      })
+      .then(result => {
+        if (result.error) {
+          reject(result.error)
+        } else {
+          // add security context
+          const parsedActivity = JSON.parse(activity)
+          if (Array.isArray(parsedActivity['@context'])) {
+            parsedActivity['@context'].push('https://w3id.org/security/v1')
+          } else {
+            const context = [parsedActivity['@context']]
+            context.push('https://w3id.org/security/v1')
+            parsedActivity['@context'] = context
+          }
 
-    if (result.error) {
-      reject(result.error)
-    } else {
-      // add security context
-      const parsedActivity = JSON.parse(activity)
-      if (Array.isArray(parsedActivity['@context'])) {
-        parsedActivity['@context'].push('https://w3id.org/security/v1')
-      } else {
-        const context = [parsedActivity['@context']]
-        context.push('https://w3id.org/security/v1')
-        parsedActivity['@context'] = context
-      }
+          // deduplicate context strings
+          parsedActivity['@context'] = [...new Set(parsedActivity['@context'])]
+          const privateKey = result.data.User[0].privateKey
+          const date = new Date().toUTCString()
 
-      // deduplicate context strings
-      parsedActivity['@context'] = [...new Set(parsedActivity['@context'])]
-      const privateKey = result.data.User[0].privateKey
-      const date = new Date().toUTCString()
-
-      debug(`url = ${url}`)
-      request(
-        {
-          url: url,
-          headers: {
-            Host: targetDomain,
-            Date: date,
-            Signature: createSignature({
-              privateKey,
-              keyId: `${activityPub.endpoint}/activitypub/users/${fromName}#main-key`,
-              url,
+          debug(`url = ${url}`)
+          request(
+            {
+              url: url,
               headers: {
                 Host: targetDomain,
                 Date: date,
+                Signature: createSignature({
+                  privateKey,
+                  keyId: `${activityPub.endpoint}/activitypub/users/${fromName}#main-key`,
+                  url,
+                  headers: {
+                    Host: targetDomain,
+                    Date: date,
+                    'Content-Type': 'application/activity+json',
+                  },
+                }),
                 'Content-Type': 'application/activity+json',
               },
-            }),
-            'Content-Type': 'application/activity+json',
-          },
-          method: 'POST',
-          body: JSON.stringify(parsedActivity),
-        },
-        (error, response) => {
-          if (error) {
-            debug(`Error = ${JSON.stringify(error, null, 2)}`)
-            reject(error)
-          } else {
-            debug('Response Headers:', JSON.stringify(response.headers, null, 2))
-            debug('Response Body:', JSON.stringify(response.body, null, 2))
-            resolve()
-          }
-        },
-      )
-    }
+              method: 'POST',
+              body: JSON.stringify(parsedActivity),
+            },
+            (error, response) => {
+              if (error) {
+                debug(`Error = ${JSON.stringify(error, null, 2)}`)
+                reject(error)
+              } else {
+                debug('Response Headers:', JSON.stringify(response.headers, null, 2))
+                debug('Response Body:', JSON.stringify(response.body, null, 2))
+                resolve()
+              }
+            },
+          )
+        }
+      })
   })
 }
diff --git a/backend/src/middleware/permissionsMiddleware.js b/backend/src/middleware/permissionsMiddleware.js
index afc38a65c..d972603a6 100644
--- a/backend/src/middleware/permissionsMiddleware.js
+++ b/backend/src/middleware/permissionsMiddleware.js
@@ -97,8 +97,6 @@ const invitationLimitReached = rule({
       return record.get('limitReached')
     })
     return limitReached
-  } catch (e) {
-    throw e
   } finally {
     session.close()
   }
diff --git a/backend/src/middleware/slugify/uniqueSlug.js b/backend/src/middleware/slugify/uniqueSlug.js
index 69aef2d1b..ca37cd562 100644
--- a/backend/src/middleware/slugify/uniqueSlug.js
+++ b/backend/src/middleware/slugify/uniqueSlug.js
@@ -1,6 +1,6 @@
 import slugify from 'slug'
 export default async function uniqueSlug(string, isUnique) {
-  let slug = slugify(string || 'anonymous', {
+  const slug = slugify(string || 'anonymous', {
     lower: true,
   })
   if (await isUnique(slug)) return slug
diff --git a/backend/src/middleware/xssMiddleware.js b/backend/src/middleware/xssMiddleware.js
index 06aa5b306..6894e8601 100644
--- a/backend/src/middleware/xssMiddleware.js
+++ b/backend/src/middleware/xssMiddleware.js
@@ -8,8 +8,8 @@ import linkifyHtml from 'linkifyjs/html'
 const embedToAnchor = content => {
   const $ = cheerio.load(content)
   $('div[data-url-embed]').each((i, el) => {
-    let url = el.attribs['data-url-embed']
-    let aTag = $(`<a href="${url}" target="_blank" data-url-embed="">${url}</a>`)
+    const url = el.attribs['data-url-embed']
+    const aTag = $(`<a href="${url}" target="_blank" data-url-embed="">${url}</a>`)
     $(el).replaceWith(aTag)
   })
   return $('body').html()
@@ -87,7 +87,7 @@ function clean(dirty) {
       b: 'strong',
       s: 'strike',
       img: function(tagName, attribs) {
-        let src = attribs.src
+        const src = attribs.src
 
         if (!src) {
           // remove broken images
diff --git a/backend/src/schema/resolvers/comments.js b/backend/src/schema/resolvers/comments.js
index 31219d6d9..89a2040f4 100644
--- a/backend/src/schema/resolvers/comments.js
+++ b/backend/src/schema/resolvers/comments.js
@@ -18,7 +18,7 @@ export default {
         false,
       )
 
-      let transactionRes = await session.run(
+      const transactionRes = await session.run(
         `
         MATCH (post:Post {id: $postId}), (comment:Comment {id: $commentId}), (author:User {id: $userId})
         MERGE (post)<-[:COMMENTS]-(comment)<-[:WROTE]-(author)
diff --git a/backend/src/schema/resolvers/comments.spec.js b/backend/src/schema/resolvers/comments.spec.js
index 890ba5feb..e8280bd4b 100644
--- a/backend/src/schema/resolvers/comments.spec.js
+++ b/backend/src/schema/resolvers/comments.spec.js
@@ -5,7 +5,6 @@ import { host, login, gql } from '../../jest/helpers'
 const factory = Factory()
 let client
 let createCommentVariables
-let createPostVariables
 let createCommentVariablesSansPostId
 let createCommentVariablesWithNonExistentPost
 let userParams
@@ -26,7 +25,7 @@ const createCommentMutation = gql`
     }
   }
 `
-createPostVariables = {
+const createPostVariables = {
   id: 'p1',
   title: 'post to comment on',
   content: 'please comment on me',
@@ -325,7 +324,7 @@ describe('ManageComments', () => {
       }
     `
 
-    let deleteCommentVariables = {
+    const deleteCommentVariables = {
       id: 'c456',
     }
 
diff --git a/backend/src/schema/resolvers/follow.js b/backend/src/schema/resolvers/follow.js
index 4e9a3b27d..730a66cfd 100644
--- a/backend/src/schema/resolvers/follow.js
+++ b/backend/src/schema/resolvers/follow.js
@@ -4,7 +4,7 @@ export default {
       const { id, type } = params
 
       const session = context.driver.session()
-      let transactionRes = await session.run(
+      const transactionRes = await session.run(
         `MATCH (node {id: $id}), (user:User {id: $userId})
           WHERE $type IN labels(node) AND NOT $id = $userId
           MERGE (user)-[relation:FOLLOWS]->(node)
@@ -29,7 +29,7 @@ export default {
       const { id, type } = params
       const session = context.driver.session()
 
-      let transactionRes = await session.run(
+      const transactionRes = await session.run(
         `MATCH (user:User {id: $userId})-[relation:FOLLOWS]->(node {id: $id})
           WHERE $type IN labels(node)
           DELETE relation
diff --git a/backend/src/schema/resolvers/follow.spec.js b/backend/src/schema/resolvers/follow.spec.js
index d29e17938..66be20841 100644
--- a/backend/src/schema/resolvers/follow.spec.js
+++ b/backend/src/schema/resolvers/follow.spec.js
@@ -41,8 +41,7 @@ describe('follow', () => {
   describe('follow user', () => {
     describe('unauthenticated follow', () => {
       it('throws authorization error', async () => {
-        let client
-        client = new GraphQLClient(host)
+        const client = new GraphQLClient(host)
         await expect(client.request(mutationFollowUser('u2'))).rejects.toThrow('Not Authorised')
       })
     })
@@ -93,8 +92,7 @@ describe('follow', () => {
         // follow
         await clientUser1.request(mutationFollowUser('u2'))
         // unfollow
-        let client
-        client = new GraphQLClient(host)
+        const client = new GraphQLClient(host)
         await expect(client.request(mutationUnfollowUser('u2'))).rejects.toThrow('Not Authorised')
       })
     })
diff --git a/backend/src/schema/resolvers/notifications.spec.js b/backend/src/schema/resolvers/notifications.spec.js
index 3876a4be3..8d51ebfbb 100644
--- a/backend/src/schema/resolvers/notifications.spec.js
+++ b/backend/src/schema/resolvers/notifications.spec.js
@@ -4,7 +4,7 @@ import { host, login } from '../../jest/helpers'
 
 const factory = Factory()
 let client
-let userParams = {
+const userParams = {
   id: 'you',
   email: 'test@example.org',
   password: '1234',
@@ -34,7 +34,7 @@ describe('Notification', () => {
 })
 
 describe('currentUser { notifications }', () => {
-  let variables = {}
+  const variables = {}
 
   describe('authenticated', () => {
     let headers
@@ -79,7 +79,7 @@ describe('currentUser { notifications }', () => {
             }
           }
         }`
-        let variables = { read: false }
+        const variables = { read: false }
         it('returns only unread notifications of current user', async () => {
           const expected = {
             currentUser: {
diff --git a/backend/src/schema/resolvers/passwordReset.js b/backend/src/schema/resolvers/passwordReset.js
index 88d82846a..d2012c0fd 100644
--- a/backend/src/schema/resolvers/passwordReset.js
+++ b/backend/src/schema/resolvers/passwordReset.js
@@ -41,7 +41,7 @@ export default {
       SET u.encryptedPassword = $encryptedNewPassword
       RETURN pr
       `
-      let transactionRes = await session.run(cypher, {
+      const transactionRes = await session.run(cypher, {
         stillValid,
         email,
         code,
diff --git a/backend/src/schema/resolvers/passwordReset.spec.js b/backend/src/schema/resolvers/passwordReset.spec.js
index 545945f51..b54b25a80 100644
--- a/backend/src/schema/resolvers/passwordReset.spec.js
+++ b/backend/src/schema/resolvers/passwordReset.spec.js
@@ -10,7 +10,7 @@ const driver = getDriver()
 
 const getAllPasswordResets = async () => {
   const session = driver.session()
-  let transactionRes = await session.run('MATCH (r:PasswordReset) RETURN r')
+  const transactionRes = await session.run('MATCH (r:PasswordReset) RETURN r')
   const resets = transactionRes.records.map(record => record.get('r'))
   session.close()
   return resets
@@ -84,9 +84,9 @@ describe('passwordReset', () => {
     }
 
     const mutation = `mutation($code: String!, $email: String!, $newPassword: String!) { resetPassword(code: $code, email: $email, newPassword: $newPassword) }`
-    let email = 'user@example.org'
-    let code = 'abcdef'
-    let newPassword = 'supersecret'
+    const email = 'user@example.org'
+    const code = 'abcdef'
+    const newPassword = 'supersecret'
     let variables
 
     describe('invalid email', () => {
diff --git a/backend/src/schema/resolvers/posts.spec.js b/backend/src/schema/resolvers/posts.spec.js
index 233be450a..6714c93ad 100644
--- a/backend/src/schema/resolvers/posts.spec.js
+++ b/backend/src/schema/resolvers/posts.spec.js
@@ -337,7 +337,7 @@ describe('DeletePost', () => {
     }
   `
 
-  let variables = {
+  const variables = {
     id: 'p1',
   }
 
diff --git a/backend/src/schema/resolvers/registration.spec.js b/backend/src/schema/resolvers/registration.spec.js
index dc2e96348..9f9a171f7 100644
--- a/backend/src/schema/resolvers/registration.spec.js
+++ b/backend/src/schema/resolvers/registration.spec.js
@@ -300,7 +300,7 @@ describe('SignupVerification', () => {
       }
     `
   describe('given valid password and email', () => {
-    let variables = {
+    const variables = {
       nonce: '123456',
       name: 'John Doe',
       password: '123',
diff --git a/backend/src/schema/resolvers/reports.js b/backend/src/schema/resolvers/reports.js
index 67c896939..79cae032b 100644
--- a/backend/src/schema/resolvers/reports.js
+++ b/backend/src/schema/resolvers/reports.js
@@ -60,7 +60,7 @@ export default {
       if (!dbResponse) return null
       const { report, submitter, resource, type } = dbResponse
 
-      let response = {
+      const response = {
         ...report.properties,
         post: null,
         comment: null,
diff --git a/backend/src/schema/resolvers/rewards.js b/backend/src/schema/resolvers/rewards.js
index f7a759aa4..74c7860e4 100644
--- a/backend/src/schema/resolvers/rewards.js
+++ b/backend/src/schema/resolvers/rewards.js
@@ -4,7 +4,7 @@ import { UserInputError } from 'apollo-server'
 const instance = neode()
 
 const getUserAndBadge = async ({ badgeKey, userId }) => {
-  let user = await instance.first('User', 'id', userId)
+  const user = await instance.first('User', 'id', userId)
   const badge = await instance.first('Badge', 'id', badgeKey)
   if (!user) throw new UserInputError("Couldn't find a user with that id")
   if (!badge) throw new UserInputError("Couldn't find a badge with that id")
@@ -36,8 +36,6 @@ export default {
             userId,
           },
         )
-      } catch (err) {
-        throw err
       } finally {
         session.close()
       }
diff --git a/backend/src/schema/resolvers/shout.js b/backend/src/schema/resolvers/shout.js
index d2d7f652e..398e43d77 100644
--- a/backend/src/schema/resolvers/shout.js
+++ b/backend/src/schema/resolvers/shout.js
@@ -4,7 +4,7 @@ export default {
       const { id, type } = params
 
       const session = context.driver.session()
-      let transactionRes = await session.run(
+      const transactionRes = await session.run(
         `MATCH (node {id: $id})<-[:WROTE]-(userWritten:User), (user:User {id: $userId})
           WHERE $type IN labels(node) AND NOT userWritten.id = $userId
           MERGE (user)-[relation:SHOUTED]->(node)
@@ -29,7 +29,7 @@ export default {
       const { id, type } = params
       const session = context.driver.session()
 
-      let transactionRes = await session.run(
+      const transactionRes = await session.run(
         `MATCH (user:User {id: $userId})-[relation:SHOUTED]->(node {id: $id})
           WHERE $type IN labels(node)
           DELETE relation
diff --git a/backend/src/schema/resolvers/shout.spec.js b/backend/src/schema/resolvers/shout.spec.js
index a94f7ca0b..029e6998c 100644
--- a/backend/src/schema/resolvers/shout.spec.js
+++ b/backend/src/schema/resolvers/shout.spec.js
@@ -60,8 +60,7 @@ describe('shout', () => {
   describe('shout foreign post', () => {
     describe('unauthenticated shout', () => {
       it('throws authorization error', async () => {
-        let client
-        client = new GraphQLClient(host)
+        const client = new GraphQLClient(host)
         await expect(client.request(mutationShoutPost('p1'))).rejects.toThrow('Not Authorised')
       })
     })
@@ -109,8 +108,7 @@ describe('shout', () => {
         // shout
         await clientUser1.request(mutationShoutPost('p2'))
         // unshout
-        let client
-        client = new GraphQLClient(host)
+        const client = new GraphQLClient(host)
         await expect(client.request(mutationUnshoutPost('p2'))).rejects.toThrow('Not Authorised')
       })
     })
diff --git a/backend/src/schema/resolvers/statistics.js b/backend/src/schema/resolvers/statistics.js
index f09b7219d..982c2acfa 100644
--- a/backend/src/schema/resolvers/statistics.js
+++ b/backend/src/schema/resolvers/statistics.js
@@ -1,9 +1,9 @@
 export const query = (cypher, session) => {
   return new Promise((resolve, reject) => {
-    let data = []
+    const data = []
     session.run(cypher).subscribe({
       onNext: function(record) {
-        let item = {}
+        const item = {}
         record.keys.forEach(key => {
           item[key] = record.get(key)
         })
@@ -34,7 +34,7 @@ const queryOne = (cypher, session) => {
 export default {
   Query: {
     statistics: async (parent, args, { driver, user }) => {
-      return new Promise(async resolve => {
+      return new Promise(resolve => {
         const session = driver.session()
         const queries = {
           countUsers:
@@ -54,18 +54,24 @@ export default {
           countFollows: 'MATCH (:User)-[r:FOLLOWS]->(:User) RETURN COUNT(r) AS countFollows',
           countShouts: 'MATCH (:User)-[r:SHOUTED]->(:Post) RETURN COUNT(r) AS countShouts',
         }
-        let data = {
-          countUsers: (await queryOne(queries.countUsers, session)).countUsers.low,
-          countPosts: (await queryOne(queries.countPosts, session)).countPosts.low,
-          countComments: (await queryOne(queries.countComments, session)).countComments.low,
-          countNotifications: (await queryOne(queries.countNotifications, session))
-            .countNotifications.low,
-          countOrganizations: (await queryOne(queries.countOrganizations, session))
-            .countOrganizations.low,
-          countProjects: (await queryOne(queries.countProjects, session)).countProjects.low,
-          countInvites: (await queryOne(queries.countInvites, session)).countInvites.low,
-          countFollows: (await queryOne(queries.countFollows, session)).countFollows.low,
-          countShouts: (await queryOne(queries.countShouts, session)).countShouts.low,
+        const data = {
+          countUsers: queryOne(queries.countUsers, session).then(res => res.countUsers.low),
+          countPosts: queryOne(queries.countPosts, session).then(res => res.countPosts.low),
+          countComments: queryOne(queries.countComments, session).then(
+            res => res.countComments.low,
+          ),
+          countNotifications: queryOne(queries.countNotifications, session).then(
+            res => res.countNotifications.low,
+          ),
+          countOrganizations: queryOne(queries.countOrganizations, session).then(
+            res => res.countOrganizations.low,
+          ),
+          countProjects: queryOne(queries.countProjects, session).then(
+            res => res.countProjects.low,
+          ),
+          countInvites: queryOne(queries.countInvites, session).then(res => res.countInvites.low),
+          countFollows: queryOne(queries.countFollows, session).then(res => res.countFollows.low),
+          countShouts: queryOne(queries.countShouts, session).then(res => res.countShouts.low),
         }
         resolve(data)
       })
diff --git a/backend/src/schema/resolvers/user_management.js b/backend/src/schema/resolvers/user_management.js
index 7ed84586b..be790ca3a 100644
--- a/backend/src/schema/resolvers/user_management.js
+++ b/backend/src/schema/resolvers/user_management.js
@@ -49,7 +49,7 @@ export default {
       }
     },
     changePassword: async (_, { oldPassword, newPassword }, { driver, user }) => {
-      let currentUser = await instance.find('User', user.id)
+      const currentUser = await instance.find('User', user.id)
 
       const encryptedPassword = currentUser.get('encryptedPassword')
       if (!(await bcrypt.compareSync(oldPassword, encryptedPassword))) {
diff --git a/backend/src/schema/resolvers/user_management.spec.js b/backend/src/schema/resolvers/user_management.spec.js
index 50b5896b3..ff0c0db4e 100644
--- a/backend/src/schema/resolvers/user_management.spec.js
+++ b/backend/src/schema/resolvers/user_management.spec.js
@@ -296,7 +296,7 @@ describe('change password', () => {
 
   describe('correct password', () => {
     it('changes the password if given correct credentials "', async () => {
-      let response = await client.request(
+      const response = await client.request(
         mutation({
           oldPassword: '1234',
           newPassword: '12345',
diff --git a/backend/src/schema/resolvers/users.js b/backend/src/schema/resolvers/users.js
index c0826c6c8..77e4ae2aa 100644
--- a/backend/src/schema/resolvers/users.js
+++ b/backend/src/schema/resolvers/users.js
@@ -23,7 +23,7 @@ export default {
     UpdateUser: async (object, args, context, resolveInfo) => {
       args = await fileUpload(args, { file: 'avatarUpload', url: 'avatar' })
       try {
-        let user = await instance.find('User', args.id)
+        const user = await instance.find('User', args.id)
         if (!user) return null
         await user.update(args)
         return user.toJson()
@@ -60,7 +60,7 @@ export default {
       const { id } = parent
       const statement = `MATCH(u:User {id: {id}})-[:PRIMARY_EMAIL]->(e:EmailAddress) RETURN e`
       const result = await instance.cypher(statement, { id })
-      let [{ email }] = result.records.map(r => r.get('e').properties)
+      const [{ email }] = result.records.map(r => r.get('e').properties)
       return email
     },
     ...Resolver('User', {
diff --git a/backend/src/schema/types/index.js b/backend/src/schema/types/index.js
index bcdceed44..068af64da 100644
--- a/backend/src/schema/types/index.js
+++ b/backend/src/schema/types/index.js
@@ -21,7 +21,7 @@ const findGqlFiles = dir => {
   return results
 }
 
-let typeDefs = []
+const typeDefs = []
 
 findGqlFiles(__dirname).forEach(file => {
   typeDefs.push(fs.readFileSync(file).toString('utf-8'))
diff --git a/backend/src/seed/factories/index.js b/backend/src/seed/factories/index.js
index e841b0beb..0efb2a886 100644
--- a/backend/src/seed/factories/index.js
+++ b/backend/src/seed/factories/index.js
@@ -40,15 +40,13 @@ export const cleanDatabase = async (options = {}) => {
   const cypher = 'MATCH (n) DETACH DELETE n'
   try {
     return await session.run(cypher)
-  } catch (error) {
-    throw error
   } finally {
     session.close()
   }
 }
 
 export default function Factory(options = {}) {
-  let {
+  const {
     seedServerHost = 'http://127.0.0.1:4001',
     neo4jDriver = getDriver(),
     neodeInstance = neode(),
diff --git a/backend/src/seed/seed-helpers.js b/backend/src/seed/seed-helpers.js
index 399d06670..913ca1d54 100644
--- a/backend/src/seed/seed-helpers.js
+++ b/backend/src/seed/seed-helpers.js
@@ -37,17 +37,17 @@ const difficulties = ['easy', 'medium', 'hard']
 
 export default {
   randomItem: (items, filter) => {
-    let ids = filter
+    const ids = filter
       ? Object.keys(items).filter(id => {
           return filter(items[id])
         })
       : _.keys(items)
-    let randomIds = _.shuffle(ids)
+    const randomIds = _.shuffle(ids)
     return items[randomIds.pop()]
   },
   randomItems: (items, key = 'id', min = 1, max = 1) => {
-    let randomIds = _.shuffle(_.keys(items))
-    let res = []
+    const randomIds = _.shuffle(_.keys(items))
+    const res = []
 
     const count = _.random(min, max)
 
@@ -86,8 +86,8 @@ export default {
     if (allowEmpty === false && count === 0) {
       count = 1
     }
-    let categorieIds = _.shuffle(_.keys(seederstore.categories))
-    let ids = []
+    const categorieIds = _.shuffle(_.keys(seederstore.categories))
+    const ids = []
     for (let i = 0; i < count; i++) {
       ids.push(categorieIds.pop())
     }
@@ -95,7 +95,7 @@ export default {
   },
   randomAddresses: () => {
     const count = Math.round(Math.random() * 3)
-    let addresses = []
+    const addresses = []
     for (let i = 0; i < count; i++) {
       addresses.push({
         city: faker.address.city(),
@@ -116,7 +116,7 @@ export default {
    * @param key    the field key that is represented in the values (slug, name, etc.)
    */
   mapIdsByKey: (items, values, key) => {
-    let res = []
+    const res = []
     values.forEach(value => {
       res.push(_.find(items, [key, value]).id.toString())
     })