diff --git a/services/web/scripts/helpers/batchedUpdate.mjs b/services/web/scripts/helpers/batchedUpdate.mjs
index fb746a7b55..7f89959314 100644
--- a/services/web/scripts/helpers/batchedUpdate.mjs
+++ b/services/web/scripts/helpers/batchedUpdate.mjs
@@ -1,3 +1,4 @@
+// @ts-check
 import mongodb from 'mongodb-legacy'
 import {
   db,
@@ -16,11 +17,33 @@ let BATCH_RANGE_START
 let BATCH_RANGE_END
 let BATCH_MAX_TIME_SPAN_IN_MS
 
+/**
+ * @typedef {import("mongodb").Collection} Collection
+ * @typedef {import("mongodb").Document} Document
+ * @typedef {import("mongodb").FindOptions} FindOptions
+ * @typedef {import("mongodb").UpdateFilter<Document>} UpdateDocument
+ * @typedef {import("mongodb").ObjectId} ObjectId
+ */
+
+/**
+ * @typedef {Object} BatchedUpdateOptions
+ * @property {string} [BATCH_DESCENDING]
+ * @property {string} [BATCH_LAST_ID]
+ * @property {string} [BATCH_MAX_TIME_SPAN_IN_MS]
+ * @property {string} [BATCH_RANGE_END]
+ * @property {string} [BATCH_RANGE_START]
+ * @property {string} [BATCH_SIZE]
+ * @property {string} [VERBOSE_LOGGING]
+ */
+
+/**
+ * @param {BatchedUpdateOptions} options
+ */
 function refreshGlobalOptionsForBatchedUpdate(options = {}) {
   options = Object.assign({}, options, process.env)
 
   BATCH_DESCENDING = options.BATCH_DESCENDING === 'true'
-  BATCH_SIZE = parseInt(options.BATCH_SIZE, 10) || 1000
+  BATCH_SIZE = parseInt(options.BATCH_SIZE || '1000', 10) || 1000
   VERBOSE_LOGGING = options.VERBOSE_LOGGING === 'true'
   if (options.BATCH_LAST_ID) {
     BATCH_RANGE_START = new ObjectId(options.BATCH_LAST_ID)
@@ -33,8 +56,10 @@ function refreshGlobalOptionsForBatchedUpdate(options = {}) {
       BATCH_RANGE_START = ID_EDGE_PAST
     }
   }
-  BATCH_MAX_TIME_SPAN_IN_MS =
-    parseInt(options.BATCH_MAX_TIME_SPAN_IN_MS, 10) || ONE_MONTH_IN_MS
+  BATCH_MAX_TIME_SPAN_IN_MS = parseInt(
+    options.BATCH_MAX_TIME_SPAN_IN_MS || ONE_MONTH_IN_MS.toString(),
+    10
+  )
   if (options.BATCH_RANGE_END) {
     BATCH_RANGE_END = new ObjectId(options.BATCH_RANGE_END)
   } else {
@@ -46,14 +71,23 @@ function refreshGlobalOptionsForBatchedUpdate(options = {}) {
   }
 }
 
-async function getNextBatch({
+/**
+ * @param {Collection} collection
+ * @param {Document} query
+ * @param {ObjectId} start
+ * @param {ObjectId} end
+ * @param {Document} projection
+ * @param {FindOptions} findOptions
+ * @return {Promise<Array<Document>>}
+ */
+async function getNextBatch(
   collection,
   query,
   start,
   end,
   projection,
-  findOptions,
-}) {
+  findOptions
+) {
   if (BATCH_DESCENDING) {
     query._id = {
       $gt: end,
@@ -73,21 +107,39 @@ async function getNextBatch({
     .toArray()
 }
 
+/**
+ * @param {Collection} collection
+ * @param {Array<Document>} nextBatch
+ * @param {UpdateDocument} update
+ * @return {Promise<void>}
+ */
 async function performUpdate(collection, nextBatch, update) {
-  return collection.updateMany(
+  await collection.updateMany(
     { _id: { $in: nextBatch.map(entry => entry._id) } },
     update
   )
 }
 
+/**
+ * @param {number} ms
+ * @return {ObjectId}
+ */
 function objectIdFromMs(ms) {
   return ObjectId.createFromTime(ms / 1000)
 }
 
+/**
+ * @param {ObjectId} id
+ * @return {number}
+ */
 function getMsFromObjectId(id) {
   return id.getTimestamp().getTime()
 }
 
+/**
+ * @param {ObjectId} start
+ * @return {ObjectId}
+ */
 function getNextEnd(start) {
   let end
   if (BATCH_DESCENDING) {
@@ -104,6 +156,10 @@ function getNextEnd(start) {
   return end
 }
 
+/**
+ * @param {Collection} collection
+ * @return {Promise<ObjectId|null>}
+ */
 async function getIdEdgePast(collection) {
   const [first] = await collection
     .find({})
@@ -112,11 +168,19 @@ async function getIdEdgePast(collection) {
     .limit(1)
     .toArray()
   if (!first) return null
-  // Go 1s further into the past in order to include the first entry via
+  // Go one second further into the past in order to include the first entry via
   // first._id > ID_EDGE_PAST
   return objectIdFromMs(Math.max(0, getMsFromObjectId(first._id) - 1000))
 }
 
+/**
+ * @param {string} collectionName
+ * @param {Document} query
+ * @param {UpdateDocument | ((batch: Array<Document>) => Promise<void>)} update
+ * @param {Document} [projection]
+ * @param {FindOptions} [findOptions]
+ * @param {BatchedUpdateOptions} [batchedUpdateOptions]
+ */
 async function batchedUpdate(
   collectionName,
   query,
@@ -143,14 +207,14 @@ async function batchedUpdate(
 
   while (start !== BATCH_RANGE_END) {
     let end = getNextEnd(start)
-    nextBatch = await getNextBatch({
+    nextBatch = await getNextBatch(
       collection,
       query,
       start,
       end,
       projection,
-      findOptions,
-    })
+      findOptions
+    )
     if (nextBatch.length > 0) {
       end = nextBatch[nextBatch.length - 1]._id
       updated += nextBatch.length
@@ -177,14 +241,30 @@ async function batchedUpdate(
   return updated
 }
 
+/**
+ * @param {string} collectionName
+ * @param {Document} query
+ * @param {UpdateDocument | ((batch: Array<Object>) => Promise<void>)} update
+ * @param {Document} [projection]
+ * @param {FindOptions} [findOptions]
+ * @param {BatchedUpdateOptions} [batchedUpdateOptions]
+ */
 function batchedUpdateWithResultHandling(
-  collection,
+  collectionName,
   query,
   update,
   projection,
-  options
+  findOptions,
+  batchedUpdateOptions
 ) {
-  batchedUpdate(collection, query, update, projection, options)
+  batchedUpdate(
+    collectionName,
+    query,
+    update,
+    projection,
+    findOptions,
+    batchedUpdateOptions
+  )
     .then(processed => {
       console.error({ processed })
       process.exit(0)