diff --git a/functions/.eslintrc.js b/functions/.eslintrc.js
index 5d66d2c6..91ca1cea 100644
--- a/functions/.eslintrc.js
+++ b/functions/.eslintrc.js
@@ -9,17 +9,27 @@ module.exports = {
     {
       files: ['**/*.ts'],
       plugins: ['@typescript-eslint'],
+      extends: ['plugin:@typescript-eslint/recommended'],
       parser: '@typescript-eslint/parser',
       parserOptions: {
         tsconfigRootDir: __dirname,
         project: ['./tsconfig.json'],
       },
+      rules: {
+        '@typescript-eslint/no-explicit-any': 'off',
+        '@typescript-eslint/no-extra-semi': 'off',
+        '@typescript-eslint/no-unused-vars': [
+          'error',
+          {
+            argsIgnorePattern: '^_',
+            varsIgnorePattern: '^_',
+            caughtErrorsIgnorePattern: '^_',
+          },
+        ],
+      },
     },
   ],
   rules: {
-    'no-extra-semi': 'off',
-    'no-unused-vars': 'off',
-    'no-constant-condition': ['error', { checkLoops: false }],
     'lodash/import-scope': [2, 'member'],
   },
 }
diff --git a/functions/src/api.ts b/functions/src/api.ts
index 36b63692..a305197e 100644
--- a/functions/src/api.ts
+++ b/functions/src/api.ts
@@ -27,7 +27,6 @@ export class APIError {
     this.msg = msg
     this.details = details
   }
-  toJson() {}
 }
 
 export const parseCredentials = async (req: Request): Promise<Credentials> => {
diff --git a/functions/src/backup-db.ts b/functions/src/backup-db.ts
index e840b71a..163760c8 100644
--- a/functions/src/backup-db.ts
+++ b/functions/src/backup-db.ts
@@ -24,9 +24,12 @@ const bucket = 'gs://manifold-firestore-backup'
 
 export const backupDb = functions.pubsub
   .schedule('every 24 hours')
-  .onRun((context) => {
+  .onRun((_context) => {
     const projectId = process.env.GCP_PROJECT || process.env.GCLOUD_PROJECT
-    const databaseName = client.databasePath(projectId!, '(default)')
+    if (projectId == null) {
+      throw new Error('No project ID environment variable set.')
+    }
+    const databaseName = client.databasePath(projectId, '(default)')
 
     return client
       .exportDocuments({
diff --git a/functions/src/call-cloud-function.ts b/functions/src/call-cloud-function.ts
index f1e48aa7..35191343 100644
--- a/functions/src/call-cloud-function.ts
+++ b/functions/src/call-cloud-function.ts
@@ -2,10 +2,10 @@ import * as admin from 'firebase-admin'
 
 import fetch from './fetch'
 
-export const callCloudFunction = (functionName: string, data: {} = {}) => {
+export const callCloudFunction = (functionName: string, data: unknown = {}) => {
   const projectId = admin.instanceId().app.options.projectId
 
-  let url = `https://us-central1-${projectId}.cloudfunctions.net/${functionName}`
+  const url = `https://us-central1-${projectId}.cloudfunctions.net/${functionName}`
 
   return fetch(url, {
     method: 'POST',
diff --git a/functions/src/create-fold.ts b/functions/src/create-fold.ts
index 2d808673..d6a33188 100644
--- a/functions/src/create-fold.ts
+++ b/functions/src/create-fold.ts
@@ -22,17 +22,18 @@ export const createFold = functions.runWith({ minInstances: 1 }).https.onCall(
     const creator = await getUser(userId)
     if (!creator) return { status: 'error', message: 'User not found' }
 
-    let { name, about, tags } = data
+    let { name, about } = data
 
     if (!name || typeof name !== 'string')
       return { status: 'error', message: 'Name must be a non-empty string' }
-
     name = name.trim().slice(0, 140)
 
     if (typeof about !== 'string')
       return { status: 'error', message: 'About must be a string' }
     about = about.trim().slice(0, 140)
 
+    const { tags } = data
+
     if (!Array.isArray(tags))
       return { status: 'error', message: 'Tags must be an array of strings' }
 
diff --git a/functions/src/create-notification.ts b/functions/src/create-notification.ts
index bd77f690..fc5e606d 100644
--- a/functions/src/create-notification.ts
+++ b/functions/src/create-notification.ts
@@ -72,7 +72,7 @@ export const createNotification = async (
     sourceType === 'answer' ||
     sourceType === 'contract'
   ) {
-    let reasonTextPretext = getReasonTextFromReason(sourceType, reason)
+    const reasonTextPretext = getReasonTextFromReason(sourceType, reason)
 
     const notifyContractCreator = async (
       userToReasonTexts: user_to_reason_texts
diff --git a/functions/src/emails.ts b/functions/src/emails.ts
index 61fded50..2f484f36 100644
--- a/functions/src/emails.ts
+++ b/functions/src/emails.ts
@@ -3,7 +3,7 @@ import { Answer } from '../../common/answer'
 import { Bet } from '../../common/bet'
 import { getProbability } from '../../common/calculate'
 import { Comment } from '../../common/comment'
-import { Contract, FreeResponseContract } from '../../common/contract'
+import { Contract } from '../../common/contract'
 import { DPM_CREATOR_FEE } from '../../common/fees'
 import { PrivateUser, User } from '../../common/user'
 import { formatMoney, formatPercent } from '../../common/util/format'
diff --git a/functions/src/market-close-emails.ts b/functions/src/market-close-emails.ts
index bb144600..382751f6 100644
--- a/functions/src/market-close-emails.ts
+++ b/functions/src/market-close-emails.ts
@@ -40,7 +40,7 @@ async function sendMarketCloseEmails() {
       .filter((x) => !!x) as Contract[]
   })
 
-  for (let contract of contracts) {
+  for (const contract of contracts) {
     console.log(
       'sending close email for',
       contract.slug,
diff --git a/functions/src/on-fold-delete.ts b/functions/src/on-fold-delete.ts
index 7762e113..10afca43 100644
--- a/functions/src/on-fold-delete.ts
+++ b/functions/src/on-fold-delete.ts
@@ -2,7 +2,7 @@ import * as functions from 'firebase-functions'
 
 export const onFoldDelete = functions.firestore
   .document('folds/{foldId}')
-  .onDelete(async (change, context) => {
+  .onDelete(async (change, _context) => {
     const snapshot = await change.ref.collection('followers').get()
 
     // Delete followers sub-collection.
diff --git a/functions/src/scripts/cache-views.ts b/functions/src/scripts/cache-views.ts
index dc54bdf9..44ceb89a 100644
--- a/functions/src/scripts/cache-views.ts
+++ b/functions/src/scripts/cache-views.ts
@@ -52,25 +52,25 @@ async function cacheUserViews(userId: string) {
   console.log(viewCounts, lastViewTime)
 }
 
-async function deleteCache() {
-  console.log('Deleting view cache')
+// async function deleteCache() {
+//   console.log('Deleting view cache')
 
-  const users = await getValues<User>(firestore.collection('users'))
+//   const users = await getValues<User>(firestore.collection('users'))
 
-  await batchedWaitAll(
-    users.map((user) => async () => {
-      console.log('Deleting view cache for', user.username)
-      await firestore.doc(`private-users/${user.id}/cache/viewCounts`).delete()
-      await firestore
-        .doc(`private-users/${user.id}/cache/lastViewTime`)
-        .delete()
-      await firestore
-        .doc(`private-users/${user.id}/cache/contractScores`)
-        .delete()
-      await firestore.doc(`private-users/${user.id}/cache/wordScores`).delete()
-    })
-  )
-}
+//   await batchedWaitAll(
+//     users.map((user) => async () => {
+//       console.log('Deleting view cache for', user.username)
+//       await firestore.doc(`private-users/${user.id}/cache/viewCounts`).delete()
+//       await firestore
+//         .doc(`private-users/${user.id}/cache/lastViewTime`)
+//         .delete()
+//       await firestore
+//         .doc(`private-users/${user.id}/cache/contractScores`)
+//         .delete()
+//       await firestore.doc(`private-users/${user.id}/cache/wordScores`).delete()
+//     })
+//   )
+// }
 
 if (require.main === module) {
   cacheViews().then(() => process.exit())
diff --git a/functions/src/scripts/change-user-info.ts b/functions/src/scripts/change-user-info.ts
index 64858c46..65f5317f 100644
--- a/functions/src/scripts/change-user-info.ts
+++ b/functions/src/scripts/change-user-info.ts
@@ -1,5 +1,3 @@
-import * as admin from 'firebase-admin'
-
 import { initAdmin } from './script-init'
 initAdmin()
 
diff --git a/functions/src/scripts/create-private-users.ts b/functions/src/scripts/create-private-users.ts
index 37168a39..9b0c4096 100644
--- a/functions/src/scripts/create-private-users.ts
+++ b/functions/src/scripts/create-private-users.ts
@@ -11,7 +11,7 @@ async function main() {
   const snap = await firestore.collection('users').get()
   const users = snap.docs.map((d) => d.data() as User)
 
-  for (let user of users) {
+  for (const user of users) {
     const fbUser = await admin.auth().getUser(user.id)
     const email = fbUser.email
     const { username } = user
diff --git a/functions/src/scripts/denormalize.ts b/functions/src/scripts/denormalize.ts
index ca4111b0..20bfc458 100644
--- a/functions/src/scripts/denormalize.ts
+++ b/functions/src/scripts/denormalize.ts
@@ -6,7 +6,7 @@ import { DocumentSnapshot, Transaction } from 'firebase-admin/firestore'
 export type DocumentValue = {
   doc: DocumentSnapshot
   field: string
-  val: any
+  val: unknown
 }
 export type DocumentCorrespondence = [DocumentSnapshot, DocumentSnapshot[]]
 export type DocumentDiff = {
@@ -20,9 +20,9 @@ export function findDiffs(
   destPath: string
 ) {
   const diffs: DocumentDiff[] = []
-  for (let [srcDoc, destDocs] of docs) {
+  for (const [srcDoc, destDocs] of docs) {
     const srcVal = srcDoc.get(srcPath)
-    for (let destDoc of destDocs) {
+    for (const destDoc of destDocs) {
       const destVal = destDoc.get(destPath)
       if (destVal !== srcVal) {
         diffs.push({
diff --git a/functions/src/scripts/migrate-contract.ts b/functions/src/scripts/migrate-contract.ts
index b3ed6025..acfdd41e 100644
--- a/functions/src/scripts/migrate-contract.ts
+++ b/functions/src/scripts/migrate-contract.ts
@@ -18,7 +18,7 @@ async function migrateBet(contractRef: DocRef, bet: Bet) {
   await contractRef.collection('bets').doc(id).update({ shares })
 }
 
-async function migrateContract(contractRef: DocRef, contract: Contract) {
+async function migrateContract(contractRef: DocRef) {
   const bets = await contractRef
     .collection('bets')
     .get()
@@ -48,7 +48,7 @@ async function migrateContracts() {
     console.log('contract', contract.question, 'bets', bets.length)
 
     for (const bet of bets) await migrateBet(contractRef, bet)
-    await migrateContract(contractRef, contract)
+    await migrateContract(contractRef)
   }
 }
 
diff --git a/functions/src/scripts/migrate-to-cfmm.ts b/functions/src/scripts/migrate-to-cfmm.ts
index 039b04be..503dbfdf 100644
--- a/functions/src/scripts/migrate-to-cfmm.ts
+++ b/functions/src/scripts/migrate-to-cfmm.ts
@@ -57,7 +57,7 @@ async function recalculateContract(contractRef: DocRef, isCommit = false) {
         : 0
     }
 
-    for (let bet of bets) {
+    for (const bet of bets) {
       const shares = bet.sale
         ? getSoldBetPayout(bet)
         : bet.isSold
@@ -139,7 +139,7 @@ async function main() {
             !snap.empty ? [firestore.doc(`contracts/${snap.docs[0].id}`)] : []
           )
 
-  for (let contractRef of contractRefs) {
+  for (const contractRef of contractRefs) {
     await recalculateContract(contractRef, isCommit).catch((e) =>
       console.log('error: ', e, 'id=', contractRef.id)
     )
diff --git a/functions/src/scripts/migrate-to-dpm-2.ts b/functions/src/scripts/migrate-to-dpm-2.ts
index ffbd1ef2..98e2f9fc 100644
--- a/functions/src/scripts/migrate-to-dpm-2.ts
+++ b/functions/src/scripts/migrate-to-dpm-2.ts
@@ -100,7 +100,7 @@ async function recalculateContract(
 
     console.log('start', { pool, totalBets, totalShares })
 
-    for (let bet of bets) {
+    for (const bet of bets) {
       if (bet.sale) {
         const soldBet = bets.find((b) => b.id === bet.sale?.betId)
         if (!soldBet) throw new Error('invalid sold bet' + bet.sale.betId)
diff --git a/functions/src/scripts/script-init.ts b/functions/src/scripts/script-init.ts
index d3acbc66..8f65e4be 100644
--- a/functions/src/scripts/script-init.ts
+++ b/functions/src/scripts/script-init.ts
@@ -64,6 +64,7 @@ export const initAdmin = (env?: string) => {
     return
   }
   console.log(`Initializing connection to ${env} Firebase...`)
+  /* eslint-disable-next-line @typescript-eslint/no-var-requires */
   const serviceAccount = require(keyPath)
   admin.initializeApp({
     credential: admin.credential.cert(serviceAccount),
diff --git a/functions/src/sell-bet.ts b/functions/src/sell-bet.ts
index 3ef5a094..93fcb6a2 100644
--- a/functions/src/sell-bet.ts
+++ b/functions/src/sell-bet.ts
@@ -6,7 +6,6 @@ import { User } from '../../common/user'
 import { Bet } from '../../common/bet'
 import { getSellBetInfo } from '../../common/sell-bet'
 import { addObjects, removeUndefinedProps } from '../../common/util/object'
-import { Fees } from '../../common/fees'
 
 export const sellBet = functions.runWith({ minInstances: 1 }).https.onCall(
   async (
@@ -50,7 +49,8 @@ export const sellBet = functions.runWith({ minInstances: 1 }).https.onCall(
       if (!betSnap.exists) return { status: 'error', message: 'Invalid bet' }
       const bet = betSnap.data() as Bet
 
-      if (userId !== bet.userId) return { status: 'error', message: 'Not authorized' }
+      if (userId !== bet.userId)
+        return { status: 'error', message: 'Not authorized' }
       if (bet.isSold) return { status: 'error', message: 'Bet already sold' }
 
       const newBetDoc = firestore
diff --git a/functions/src/unsubscribe.ts b/functions/src/unsubscribe.ts
index baea8022..a41a7155 100644
--- a/functions/src/unsubscribe.ts
+++ b/functions/src/unsubscribe.ts
@@ -6,7 +6,8 @@ import { PrivateUser } from '../../common/user'
 export const unsubscribe = functions
   .runWith({ minInstances: 1 })
   .https.onRequest(async (req, res) => {
-    let { id, type } = req.query as { id: string; type: string }
+    const id = req.query.id as string
+    let type = req.query.type as string
     if (!id || !type) {
       res.status(400).send('Empty id or type parameter.')
       return
diff --git a/functions/src/update-feed.ts b/functions/src/update-feed.ts
index 104473c1..03b1666c 100644
--- a/functions/src/update-feed.ts
+++ b/functions/src/update-feed.ts
@@ -31,7 +31,7 @@ const MAX_BATCHES = 50
 
 const getUserBatches = async () => {
   const users = shuffle(await getValues<User>(firestore.collection('users')))
-  let userBatches: User[][] = []
+  const userBatches: User[][] = []
   for (let i = 0; i < users.length; i += BATCH_SIZE) {
     userBatches.push(users.slice(i, i + BATCH_SIZE))
   }
@@ -197,18 +197,18 @@ function getActivityScore(contract: Contract, viewTime: number | undefined) {
   return isNew ? newMappedScore : mappedScore
 }
 
-function getLastViewedScore(viewTime: number | undefined) {
-  if (viewTime === undefined) {
-    return 1
-  }
+// function getLastViewedScore(viewTime: number | undefined) {
+//   if (viewTime === undefined) {
+//     return 1
+//   }
 
-  const daysAgo = (Date.now() - viewTime) / DAY_MS
+//   const daysAgo = (Date.now() - viewTime) / DAY_MS
 
-  if (daysAgo < 0.5) {
-    const frac = logInterpolation(0, 0.5, daysAgo)
-    return 0.5 + 0.25 * frac
-  }
+//   if (daysAgo < 0.5) {
+//     const frac = logInterpolation(0, 0.5, daysAgo)
+//     return 0.5 + 0.25 * frac
+//   }
 
-  const frac = logInterpolation(0.5, 14, daysAgo)
-  return 0.75 + 0.25 * frac
-}
+//   const frac = logInterpolation(0.5, 14, daysAgo)
+//   return 0.75 + 0.25 * frac
+// }
diff --git a/functions/src/update-user-metrics.ts b/functions/src/update-user-metrics.ts
index 08dc63e6..0ab7cd8c 100644
--- a/functions/src/update-user-metrics.ts
+++ b/functions/src/update-user-metrics.ts
@@ -71,9 +71,9 @@ const computeTotalPool = async (
   return sum(pools)
 }
 
-const computeVolume = async (contract: Contract) => {
-  const bets = await getValues<Bet>(
-    firestore.collection(`contracts/${contract.id}/bets`)
-  )
-  return sumBy(bets, (bet) => Math.abs(bet.amount))
-}
+// const computeVolume = async (contract: Contract) => {
+//   const bets = await getValues<Bet>(
+//     firestore.collection(`contracts/${contract.id}/bets`)
+//   )
+//   return sumBy(bets, (bet) => Math.abs(bet.amount))
+// }