diff --git a/backend/controllers/configurations.js b/backend/controllers/configurations.js
index 05a320c..2df9d06 100644
--- a/backend/controllers/configurations.js
+++ b/backend/controllers/configurations.js
@@ -220,9 +220,11 @@ configurationsRouter.delete(
     const success = await db.Configuration.destroy({
       where: { id: req.params.configurationId },
     })
-    success
-      ? console.log(`Configuration ${req.params.configurationId} destroyed.`)
-      : console.log('Nothing to delete.')
+    if (success) {
+      console.log(`Configuration ${req.params.configurationId} destroyed.`)
+    } else {
+      console.log('Nothing to delete.')
+    }
     return res.status(204).end()
   }
 )
diff --git a/backend/controllers/email.js b/backend/controllers/email.js
index c24fdff..087c68b 100644
--- a/backend/controllers/email.js
+++ b/backend/controllers/email.js
@@ -242,7 +242,7 @@ emailRouter.get('/templates', checkAdmin, async (req, res) => {
 
     const payload = templates.length > 0 ? templates[0] : defaultEmailTemplates
     return res.json(serializeTemplatesByLanguage(payload))
-  } catch (err) {
+  } catch {
     res.status(500).json({ error: 'Something is wrong... try reloading the page' })
   }
 })
@@ -281,7 +281,7 @@ const parseTemplates = (req, res, next) => {
       templates: deserialized
     }
     next()
-  } catch (e) {
+  } catch {
     res.status(500).json({ error: 'internal server error' })
   }
 }
@@ -311,7 +311,7 @@ emailRouter.post(
         customer_review_link_eng
       })
       res.status(200).json(serializeTemplatesByLanguage(createdTemplates))
-    } catch (e) {
+    } catch {
       res.status(500).json({ error: 'Something is wrong... try reloading the page' })
     }
   }
diff --git a/backend/controllers/groups.js b/backend/controllers/groups.js
index 1c11a1c..019cffe 100644
--- a/backend/controllers/groups.js
+++ b/backend/controllers/groups.js
@@ -283,9 +283,11 @@ router.put('/:groupId', checkAdmin, async (req, res) => {
 
 router.delete('/:groupId', checkAdmin, async (req, res) => {
   const success = await db.Group.destroy({ where: { id: req.params.groupId } })
-  success
-    ? console.log(`Group ${req.params.groupId} destroyed.`)
-    : console.log('Nothing to delete.')
+  if (success) {
+    console.log(`Group ${req.params.groupId} destroyed.`)
+  } else {
+    console.log('Nothing to delete.')
+  }
   return res.status(204).end()
 })
 
diff --git a/backend/controllers/instructorTimeLogs.js b/backend/controllers/instructorTimeLogs.js
index 1cc6326..1332105 100644
--- a/backend/controllers/instructorTimeLogs.js
+++ b/backend/controllers/instructorTimeLogs.js
@@ -75,7 +75,7 @@ instructorTimeLogsRouter.get('/', checkInstructor, async (req, res) => {
   try {
     const timeLogs = await fetchAllFromDb()
     return res.status(200).json(timeLogs)
-  } catch (error) {
+  } catch {
     return res.status(500).json({ error: 'Error fetching time logs.' })
   }
 })
diff --git a/backend/controllers/timeLogs.js b/backend/controllers/timeLogs.js
index 62a5335..4d861b3 100644
--- a/backend/controllers/timeLogs.js
+++ b/backend/controllers/timeLogs.js
@@ -178,7 +178,7 @@ timeLogsRouter.get('/', checkLogin, async (req, res) => {
     const user_id = req.user.id
     const timeLogs = user_id ? await fetchFromDb(user_id) : []
     return res.status(200).json(timeLogs)
-  } catch (error) {
+  } catch {
     return res.status(500).json({ error: 'Error fetching time logs.' })
   }
 })
diff --git a/backend/index.js b/backend/index.js
index 2489089..563af52 100644
--- a/backend/index.js
+++ b/backend/index.js
@@ -33,7 +33,7 @@ const shibbolethHeaders = [
 app.use(cors())
 app.use(bodyParser.json({ limit: '100mb' }))
 app.use(headersMiddleware(shibbolethHeaders))
-isDevelopmentEnvironment() && app.use(fakeshibbo)
+if (isDevelopmentEnvironment()) app.use(fakeshibbo)
 app.use(unless('/api/login', logger))
 
 // Routers
diff --git a/frontend/.oxlintrc.json b/frontend/.oxlintrc.json
index 9a7d3f8..8c0fc98 100644
--- a/frontend/.oxlintrc.json
+++ b/frontend/.oxlintrc.json
@@ -16,5 +16,13 @@
   "rules": {
     "eqeqeq": "error",
     "react-hooks/exhaustive-deps": "warn"
-  }
+  },
+  "overrides": [
+    {
+      "files": ["src/components/RegistrationDetailsPage.jsx"],
+      "rules": {
+        "react/no-did-mount-set-state": "warn"
+      }
+    }
+  ]
 }
\ No newline at end of file
diff --git a/frontend/src/App.jsx b/frontend/src/App.jsx
index 32fe54c..d683d96 100644
--- a/frontend/src/App.jsx
+++ b/frontend/src/App.jsx
@@ -116,8 +116,8 @@ const App = (props) => {
 
     const fetchData = async () => {
       updateIsLoading(true)
-      !isCustomerReviewPage && (await handleLogin())
-      user && (await handleGroupInit())
+      if (!isCustomerReviewPage) await handleLogin()
+      if (user) await handleGroupInit()
       await fetchRegistrationManagementData()
       updateIsLoading(false)
     }
diff --git a/frontend/src/components/AdminSprintsPage/AdminSprintsPage.jsx b/frontend/src/components/AdminSprintsPage/AdminSprintsPage.jsx
index 33575d1..524157e 100644
--- a/frontend/src/components/AdminSprintsPage/AdminSprintsPage.jsx
+++ b/frontend/src/components/AdminSprintsPage/AdminSprintsPage.jsx
@@ -97,7 +97,7 @@ const AdminSprintsPage = (props) => {
       await fetchSprints(selectedGroupId)
       setIsLoading(false)
     }
-    selectedGroup?.id && fetchData(selectedGroup.id)
+    if (selectedGroup?.id) fetchData(selectedGroup.id)
   }, [selectedGroup, selectedConfiguration])
 
 
diff --git a/frontend/src/components/EmailTemplatesPage/EmailTemplatesPage.jsx b/frontend/src/components/EmailTemplatesPage/EmailTemplatesPage.jsx
index 132942c..43d3abc 100644
--- a/frontend/src/components/EmailTemplatesPage/EmailTemplatesPage.jsx
+++ b/frontend/src/components/EmailTemplatesPage/EmailTemplatesPage.jsx
@@ -27,7 +27,7 @@ class EmailTemplatesPage extends React.Component {
     try {
       await this.props.updateEmailTemplates(newTemplates)
       this.props.setSuccess('Email templates saved!')
-    } catch (e) {
+    } catch {
       this.props.setError('Failed to update email templates')
     }
   }
diff --git a/frontend/src/components/GroupManagementPage/GroupManagementPage.jsx b/frontend/src/components/GroupManagementPage/GroupManagementPage.jsx
index 3c1f317..88f0feb 100644
--- a/frontend/src/components/GroupManagementPage/GroupManagementPage.jsx
+++ b/frontend/src/components/GroupManagementPage/GroupManagementPage.jsx
@@ -37,7 +37,7 @@ const GroupManagementPage = (props) => {
         setUsers(fetchedUsers)
         setGroups(fetchedGroups)
         await fetchTopics()
-      } catch (err) {
+      } catch {
         setError('Some error happened')
       }
     }
diff --git a/frontend/src/components/InstructorReviewPage.jsx b/frontend/src/components/InstructorReviewPage.jsx
index 2468027..e26a42f 100644
--- a/frontend/src/components/InstructorReviewPage.jsx
+++ b/frontend/src/components/InstructorReviewPage.jsx
@@ -311,7 +311,7 @@ const Review = ({ student, updateAnswer, index }) => {
 const Reviews = ({ answerSheet, updateAnswer }) => {
   return answerSheet.map((student, index) => {
     return (
-      <Review student={student} updateAnswer={updateAnswer} index={index} />
+      <Review key={index} student={student} updateAnswer={updateAnswer} index={index} />
     )
   })
 }
diff --git a/frontend/src/components/PeerReviewPage.jsx b/frontend/src/components/PeerReviewPage.jsx
index d900e56..f6cbc59 100644
--- a/frontend/src/components/PeerReviewPage.jsx
+++ b/frontend/src/components/PeerReviewPage.jsx
@@ -19,7 +19,13 @@ import timeLogService from '../services/timeLogs'
 
 import TextField from '@material-ui/core/TextField'
 import Button from '@material-ui/core/Button'
-import { Table, TableHead, TableRow, TableBody, TableCell } from '@material-ui/core'
+import {
+  Table,
+  TableHead,
+  TableRow,
+  TableBody,
+  TableCell,
+} from '@material-ui/core'
 
 class PeerReview extends React.Component {
   async componentDidMount() {
@@ -264,7 +270,7 @@ const Question = ({
   updateAnswer,
   updatePeerReview,
 }) => {
-  if (!questionId === undefined) {
+  if (!questionId) {
     console.error('No questionId given')
     return (
       <div>
@@ -281,10 +287,7 @@ const Question = ({
     return (
       <div className="peer-review-box">
         <h3 className="peer-review-box__h3">{question.header}</h3>
-        <Table
-          size="small"
-          className="peer-review-box__radio-button-table"
-        >
+        <Table size="small" className="peer-review-box__radio-button-table">
           <TableHead>
             <TableRow hover>
               <TableCell className="peer-review-box__radio-header" />
diff --git a/frontend/src/components/QuestionSetForm.jsx b/frontend/src/components/QuestionSetForm.jsx
index 4c9b451..8bda75f 100644
--- a/frontend/src/components/QuestionSetForm.jsx
+++ b/frontend/src/components/QuestionSetForm.jsx
@@ -9,7 +9,7 @@ const validateQuestionsJson = (str) => {
       return { ok: false, error: 'Questions should be an array' }
     }
     return { ok: true }
-  } catch (err) {
+  } catch {
     return { ok: false, error: 'Field contains invalid JSON' }
   }
 }
diff --git a/frontend/src/components/TagPage/StudentTagPage.jsx b/frontend/src/components/TagPage/StudentTagPage.jsx
index e1a4248..7559491 100644
--- a/frontend/src/components/TagPage/StudentTagPage.jsx
+++ b/frontend/src/components/TagPage/StudentTagPage.jsx
@@ -70,7 +70,7 @@ const StudentTagPage = (props) => {
 
     const fetchData = async () => {
       setIsLoading(true)
-      group?.id && (await fetchSprints())
+      if (group?.id) await fetchSprints()
       await tagService.getTagsByStudent(user.studentNumber).then((data) => {
         setStudentTags(data)
       })
diff --git a/frontend/src/components/TimeLogsPage/InstructorTimeLogsPage.jsx b/frontend/src/components/TimeLogsPage/InstructorTimeLogsPage.jsx
index 407466d..f6fcd63 100644
--- a/frontend/src/components/TimeLogsPage/InstructorTimeLogsPage.jsx
+++ b/frontend/src/components/TimeLogsPage/InstructorTimeLogsPage.jsx
@@ -196,7 +196,7 @@ const InstructorTimeLogsPage = (props) => {
       await fetchSprintData(selectedGroupId)
       setIsLoading(false)
     }
-    selectedGroupId && fetchChartData(selectedGroupId)
+    if (selectedGroupId) fetchChartData(selectedGroupId)
   }, [selectedGroupId])
 
   const handleTimeLogCheck = (logId) => {
@@ -233,7 +233,7 @@ const InstructorTimeLogsPage = (props) => {
       const updatedLogs = await instructorTimeLogsService.deleteTimeLog(logId)
       setAllLogs(updatedLogs)
       setSuccess('Time log deleted successfully')
-    } catch (error) {
+    } catch {
       setError('Error deleting time log')
     }
   }
diff --git a/frontend/src/components/TimeLogsPage/TimeLogChart.jsx b/frontend/src/components/TimeLogsPage/TimeLogChart.jsx
index 42d6192..90e61dc 100644
--- a/frontend/src/components/TimeLogsPage/TimeLogChart.jsx
+++ b/frontend/src/components/TimeLogsPage/TimeLogChart.jsx
@@ -1,6 +1,6 @@
 import React, { useState, useEffect } from 'react'
 import { connect } from 'react-redux'
-import { ResponsiveContainer, BarChart, XAxis, YAxis, Tooltip, ReferenceLine, Label, LabelList, Bar, Cell } from 'recharts'
+import { ResponsiveContainer, BarChart, XAxis, YAxis, Tooltip, ReferenceLine, LabelList, Bar, Cell } from 'recharts'
 import { NoTimeLogsPlaceholderSprint, NoTimeLogsPlaceholderProject } from '../common/Placeholders'
 import Error from '@material-ui/icons/Error'
 import { useTheme } from '@material-ui/core/styles';
@@ -130,7 +130,7 @@ const checkStudentProgressPaceTotal = (studentName, allStudentHours, totalDurati
 const checkStudentProgressPacePerSprint = (targetStudent, allStudentHours, allSprintDates, isShortProject) => {
   const { idealHoursPerDay, okHoursPerDay, dangerousHoursPerDay } = getProjectHours(isShortProject)
   const sprintPaces = {}
-  allStudentHours.forEach((student, index) => {
+  allStudentHours.forEach((student, _index) => {
     if (student.sprint === -1)
       return
 
diff --git a/frontend/src/components/TimeLogsPage/TimeLogsPage.jsx b/frontend/src/components/TimeLogsPage/TimeLogsPage.jsx
index 4137331..d42b310 100644
--- a/frontend/src/components/TimeLogsPage/TimeLogsPage.jsx
+++ b/frontend/src/components/TimeLogsPage/TimeLogsPage.jsx
@@ -1,4 +1,4 @@
-import React, { useEffect, useState, useCallback } from 'react'
+import React, { useEffect, useState } from 'react'
 import { connect } from 'react-redux'
 import { withRouter } from 'react-router-dom'
 import { TimeLogForm } from './TimeLogForm'
@@ -107,9 +107,9 @@ const TimeLogsPage = (props) => {
     }
     const fetchData = async () => {
       setIsLoading(true)
-      group?.id && await fetchSprints()
+      if (group?.id) await fetchSprints()
       await fetchTimeLogs()
-      group?.id && await fetchGroupSprintSummary(group.id)
+      if (group?.id) await fetchGroupSprintSummary(group.id)
       await fetchTags()
       setIsLoading(false)
     }
@@ -131,12 +131,14 @@ const TimeLogsPage = (props) => {
       }
     )
 
-    currentSprintObject && setCurrentSprintNumber(currentSprintObject.sprint)
-    currentSprintObject && setSelectedSprintNumber(currentSprintObject.sprint)
-    !currentSprintObject &&
+    if (currentSprintObject) {
+      setCurrentSprintNumber(currentSprintObject.sprint)
+      setSelectedSprintNumber(currentSprintObject.sprint)
+    } else {
       setSelectedSprintNumber(
         existingSprintNumbers.length > 0 ? existingSprintNumbers.at(-1) : null
       )
+    }
   }, [allSprints])
 
   const handleSubmit = async (date, time, description, tags) => {
diff --git a/frontend/src/components/TopicFormPageInfo.jsx b/frontend/src/components/TopicFormPageInfo.jsx
index 52a7b5d..cf211da 100644
--- a/frontend/src/components/TopicFormPageInfo.jsx
+++ b/frontend/src/components/TopicFormPageInfo.jsx
@@ -5,7 +5,12 @@ import { Typography } from '@material-ui/core'
 import topicFormPageActions from '../reducers/actions/topicFormPageActions'
 import './TopicFormPageInfo.css'
 
-const TopicFormPageInfo = ({ topicOpen, topicMessage, updateShowInfo, toggle }) => {
+const TopicFormPageInfo = ({
+  topicOpen,
+  topicMessage,
+  updateShowInfo,
+  toggle,
+}) => {
   const allowCretion = topicOpen && toggle
 
   return (
@@ -30,26 +35,25 @@ const TopicFormPageInfo = ({ topicOpen, topicMessage, updateShowInfo, toggle })
       {!allowCretion && (
         <div className="topic-form-page-info-message">{topicMessage}</div>
       )}
-      {false && <span style={{ margin: 10,  color: 'white' }} onClick={() => updateShowInfo(false)}>.</span>}
     </div>
   )
 }
 
 const mapStateToProps = (state) => {
   return {
-    toggle: true || state && state.login && state.login.user && state.login.user.user && state.login.user.user.username === 'mluukkai2',
+    toggle: true,
     topicOpen: state.registrationManagement.topicRegistrationOpen,
-    topicMessage: state.registrationManagement.topicRegistrationMessage
+    topicMessage: state.registrationManagement.topicRegistrationMessage,
   }
 }
 
 const mapDispatchToProps = {
-  ...topicFormPageActions
+  ...topicFormPageActions,
 }
 
 const ConnectedTopicFormPageInfo = connect(
   mapStateToProps,
-  mapDispatchToProps
+  mapDispatchToProps,
 )(TopicFormPageInfo)
 
 export default ConnectedTopicFormPageInfo
diff --git a/frontend/src/components/ViewUsersPage/ViewUsersPage.jsx b/frontend/src/components/ViewUsersPage/ViewUsersPage.jsx
index 6c6a1fa..11a510c 100644
--- a/frontend/src/components/ViewUsersPage/ViewUsersPage.jsx
+++ b/frontend/src/components/ViewUsersPage/ViewUsersPage.jsx
@@ -19,13 +19,11 @@ const customTheme = createMuiTheme({
     overline: {
       color: 'darkOrange',
     },
+    useNextVariants: true,
   },
   link: {
     color: 'darkOrange',
   },
-  typography: {
-    useNextVariants: true,
-  },
 })
 
 const TopicDetailsLink = ({ topicId, ...props }) => (