diff --git a/backend/api-renamed/status/pat-info.js b/backend/api-renamed/status/pat-info.js
index 1b007970..46aae023 100644
--- a/backend/api-renamed/status/pat-info.js
+++ b/backend/api-renamed/status/pat-info.js
@@ -12,17 +12,12 @@ import { logger, dateDiff } from "../../src/common/utils.js";
 
 export const RATE_LIMIT_SECONDS = 60 * 3; // 1 request per 3 minutes
 
-/**
- * @typedef {import('axios').AxiosRequestHeaders} AxiosRequestHeaders Axios request headers.
- * @typedef {import('axios').AxiosResponse} AxiosResponse Axios response.
- */
-
 /**
  * Simple uptime check fetcher for the PATs.
  *
- * @param {AxiosRequestHeaders} variables Fetcher variables.
+ * @param {any} variables Fetcher variables.
  * @param {string} token GitHub token.
- * @returns {Promise<AxiosResponse>} The response.
+ * @returns {Promise<import('axios').AxiosResponse>} The response.
  */
 const uptimeFetcher = (variables, token) => {
   return request(
@@ -47,7 +42,7 @@ const getAllPATs = () => {
 };
 
 /**
- * @typedef {(variables: AxiosRequestHeaders, token: string) => Promise<AxiosResponse>} Fetcher The fetcher function.
+ * @typedef {(variables: any, token: string) => Promise<import('axios').AxiosResponse>} Fetcher The fetcher function.
  * @typedef {{validPATs: string[], expiredPATs: string[], exhaustedPATs: string[], suspendedPATs: string[], errorPATs: string[], details: any}} PATInfo The PAT info.
  */
 
@@ -55,10 +50,11 @@ const getAllPATs = () => {
  * Check whether any of the PATs is expired.
  *
  * @param {Fetcher} fetcher The fetcher function.
- * @param {AxiosRequestHeaders} variables Fetcher variables.
+ * @param {any} variables Fetcher variables.
  * @returns {Promise<PATInfo>} The response.
  */
 const getPATInfo = async (fetcher, variables) => {
+  /** @type {Record<string, any>} */
   const details = {};
   const PATs = getAllPATs();
 
diff --git a/backend/api-renamed/status/up.js b/backend/api-renamed/status/up.js
index 57f450aa..6bbc1ab4 100644
--- a/backend/api-renamed/status/up.js
+++ b/backend/api-renamed/status/up.js
@@ -13,17 +13,12 @@ import { logger } from "../../src/common/utils.js";
 
 export const RATE_LIMIT_SECONDS = 60 * 3; // 1 request per 3 minutes
 
-/**
- * @typedef {import('axios').AxiosRequestHeaders} AxiosRequestHeaders Axios request headers.
- * @typedef {import('axios').AxiosResponse} AxiosResponse Axios response.
- */
-
 /**
  * Simple uptime check fetcher for the PATs.
  *
- * @param {AxiosRequestHeaders} variables Fetcher variables.
+ * @param {any} variables Fetcher variables.
  * @param {string} token GitHub token.
- * @returns {Promise<AxiosResponse>} The response.
+ * @returns {Promise<import('axios').AxiosResponse>} The response.
  */
 const uptimeFetcher = (variables, token) => {
   return request(
diff --git a/backend/src/common/http.js b/backend/src/common/http.js
index 0f3270fe..388d1052 100644
--- a/backend/src/common/http.js
+++ b/backend/src/common/http.js
@@ -1,15 +1,10 @@
 import axios from "axios";
 
-/**
- * @typedef {import('axios').AxiosRequestConfig['data']} AxiosRequestConfigData Axios request data.
- * @typedef {import('axios').AxiosRequestConfig['headers']} AxiosRequestConfigHeaders Axios request headers.
- */
-
 /**
  * Send GraphQL request to GitHub API.
  *
- * @param {AxiosRequestConfigData} data Request data.
- * @param {AxiosRequestConfigHeaders} headers Request headers.
+ * @param {import('axios').AxiosRequestConfig['data']} data Request data.
+ * @param {import('axios').AxiosRequestConfig['headers']} headers Request headers.
  * @returns {Promise<any>} Request response.
  */
 const request = (data, headers) => {
diff --git a/backend/src/common/retryer.js b/backend/src/common/retryer.js
index 45831337..ab01bda7 100644
--- a/backend/src/common/retryer.js
+++ b/backend/src/common/retryer.js
@@ -13,14 +13,14 @@ const RETRIES = process.env.NODE_ENV === "test" ? 7 : PATs;
 
 /**
  * @typedef {import("axios").AxiosResponse} AxiosResponse Axios response.
- * @typedef {(variables: object, token: string, retriesForTests?: number) => Promise<AxiosResponse>} FetcherFunction Fetcher function.
+ * @typedef {(variables: any, token: string, retriesForTests?: number) => Promise<AxiosResponse>} FetcherFunction Fetcher function.
  */
 
 /**
  * Try to execute the fetcher function until it succeeds or the max number of retries is reached.
  *
  * @param {FetcherFunction} fetcher The fetcher function.
- * @param {object} variables Object with arguments to pass to the fetcher function.
+ * @param {any} variables Object with arguments to pass to the fetcher function.
  * @param {number} retries How many times to retry.
  * @returns {Promise<any>} The response from the fetcher function.
  */
diff --git a/backend/src/fetchers/gist.js b/backend/src/fetchers/gist.js
index 635892cf..d9cccc67 100644
--- a/backend/src/fetchers/gist.js
+++ b/backend/src/fetchers/gist.js
@@ -4,11 +4,6 @@ import { retryer } from "../common/retryer.js";
 import { MissingParamError } from "../common/error.js";
 import { request } from "../common/http.js";
 
-/**
- * @typedef {import('axios').AxiosRequestHeaders} AxiosRequestHeaders Axios request headers.
- * @typedef {import('axios').AxiosResponse} AxiosResponse Axios response.
- */
-
 const QUERY = `
 query gistInfo($gistName: String!) {
     viewer {
@@ -36,9 +31,9 @@ query gistInfo($gistName: String!) {
 /**
  * Gist data fetcher.
  *
- * @param {AxiosRequestHeaders} variables Fetcher variables.
+ * @param {object} variables Fetcher variables.
  * @param {string} token GitHub token.
- * @returns {Promise<AxiosResponse>} The response.
+ * @returns {Promise<import('axios').AxiosResponse>} The response.
  */
 const fetcher = async (variables, token) => {
   return await request(
@@ -58,7 +53,9 @@ const fetcher = async (variables, token) => {
  * @returns {string} Primary language.
  */
 const calculatePrimaryLanguage = (files) => {
+  /** @type {Record<string, number>} */
   const languages = {};
+
   for (const file of files) {
     if (file.language) {
       if (languages[file.language.name]) {
@@ -68,12 +65,14 @@ const calculatePrimaryLanguage = (files) => {
       }
     }
   }
+
   let primaryLanguage = Object.keys(languages)[0];
   for (const language in languages) {
     if (languages[language] > languages[primaryLanguage]) {
       primaryLanguage = language;
     }
   }
+
   return primaryLanguage;
 };
 
diff --git a/backend/src/fetchers/repo.js b/backend/src/fetchers/repo.js
index 1434b39e..6d45f4e7 100644
--- a/backend/src/fetchers/repo.js
+++ b/backend/src/fetchers/repo.js
@@ -5,17 +5,12 @@ import { request } from "../common/http.js";
 import { retryer } from "../common/retryer.js";
 import { fetchRepoUserStats } from "./stats.js";
 
-/**
- * @typedef {import('axios').AxiosRequestHeaders} AxiosRequestHeaders Axios request headers.
- * @typedef {import('axios').AxiosResponse} AxiosResponse Axios response.
- */
-
 /**
  * Repo data fetcher.
  *
- * @param {AxiosRequestHeaders} variables Fetcher variables.
+ * @param {object} variables Fetcher variables.
  * @param {string} token GitHub token.
- * @returns {Promise<AxiosResponse>} The response.
+ * @returns {Promise<import('axios').AxiosResponse>} The response.
  */
 const fetcher = (variables, token) => {
   return request(
diff --git a/backend/src/fetchers/stats.js b/backend/src/fetchers/stats.js
index 88941588..1f54bdb3 100644
--- a/backend/src/fetchers/stats.js
+++ b/backend/src/fetchers/stats.js
@@ -82,16 +82,12 @@ const GRAPHQL_STATS_QUERY = `
   }
 `;
 
-/**
- * @typedef {import('axios').AxiosResponse} AxiosResponse Axios response.
- */
-
 /**
  * Stats fetcher object.
  *
- * @param {object} variables Fetcher variables.
+ * @param {object & { after: string | null }} variables Fetcher variables.
  * @param {string} token GitHub token.
- * @returns {Promise<AxiosResponse>} Axios response.
+ * @returns {Promise<import('axios').AxiosResponse>} Axios response.
  */
 const fetcher = (variables, token) => {
   const query = variables.after ? GRAPHQL_REPOS_QUERY : GRAPHQL_STATS_QUERY;
@@ -116,7 +112,7 @@ const fetcher = (variables, token) => {
  * @param {boolean} variables.includeDiscussionsAnswers Include discussions answers.
  * @param {string|undefined} variables.startTime Time to start the count of total commits.
  * @param {string[]} ownerAffiliations The owner affiliations to filter by. Default: OWNER.
- * @returns {Promise<AxiosResponse>} Axios response.
+ * @returns {Promise<import('axios').AxiosResponse>} Axios response.
  *
  * @description This function supports multi-page fetching if the 'FETCH_MULTI_PAGE_STARS' environment variable is set to true.
  */
@@ -169,6 +165,35 @@ const statsFetcher = async ({
   return stats;
 };
 
+/**
+ * Fetch total commits using the REST API.
+ *
+ * @param {object} variables Fetcher variables.
+ * @param {string} token GitHub token.
+ * @returns {Promise<import('axios').AxiosResponse>} Axios response.
+ *
+ * @see https://developer.github.com/v3/search/#search-commits
+ */
+const fetchTotalItems = (variables, token) => {
+  return axios({
+    method: "get",
+    url:
+      `https://api.github.com/search/` +
+      type +
+      `?per_page=1&q=` +
+      buildSearchFilter(variables.repo, variables.owner).replaceAll(
+        " ",
+        "+",
+      ) +
+      filter,
+    headers: {
+      "Content-Type": "application/json",
+      Accept: "application/vnd.github.cloak-preview",
+      Authorization: `token ${token}`,
+    },
+  });
+};
+
 /**
  * Fetch all the commits for all the repositories of a given username.
  *
@@ -184,27 +209,6 @@ const totalItemsFetcher = async (username, repo, owner, type, filter) => {
     throw new Error("Invalid username provided.");
   }
 
-  // https://developer.github.com/v3/search/#search-commits
-  const fetchTotalItems = (variables, token) => {
-    return axios({
-      method: "get",
-      url:
-        `https://api.github.com/search/` +
-        type +
-        `?per_page=1&q=` +
-        buildSearchFilter(variables.repo, variables.owner).replaceAll(
-          " ",
-          "+",
-        ) +
-        filter,
-      headers: {
-        "Content-Type": "application/json",
-        Accept: "application/vnd.github.cloak-preview",
-        Authorization: `token ${token}`,
-      },
-    });
-  };
-
   let res;
   try {
     res = await retryer(fetchTotalItems, {
@@ -287,10 +291,6 @@ const fetchRepoUserStats = async (
   return stats;
 };
 
-/**
- * @typedef {import("./types").StatsData} StatsData Stats data.
- */
-
 /**
  * Fetch stats for a given username.
  *
@@ -303,7 +303,7 @@ const fetchRepoUserStats = async (
  * @param {string[]} ownerAffiliations Owner affiliations. Default: OWNER.
  * @param {number|undefined} commits_year Year to count total commits
  * @param {string[]} ownerAffiliations Owner affiliations. Default: OWNER.
- * @returns {Promise<StatsData>} Stats data.
+ * @returns {Promise<import("./types").StatsData>} Stats data.
  */
 const fetchStats = async (
   username,
diff --git a/backend/src/fetchers/top-languages.js b/backend/src/fetchers/top-languages.js
index 680232e4..33a7c977 100644
--- a/backend/src/fetchers/top-languages.js
+++ b/backend/src/fetchers/top-languages.js
@@ -10,17 +10,12 @@ import { CustomError, MissingParamError } from "../common/error.js";
 import { wrapTextMultiline } from "../common/fmt.js";
 import { request } from "../common/http.js";
 
-/**
- * @typedef {import("axios").AxiosRequestHeaders} AxiosRequestHeaders Axios request headers.
- * @typedef {import("axios").AxiosResponse} AxiosResponse Axios response.
- */
-
 /**
  * Top languages fetcher object.
  *
- * @param {AxiosRequestHeaders} variables Fetcher variables.
+ * @param {any} variables Fetcher variables.
  * @param {string} token GitHub token.
- * @returns {Promise<AxiosResponse>} Languages fetcher response.
+ * @returns {Promise<import("axios").AxiosResponse>} Languages fetcher response.
  */
 const fetcher = (variables, token) => {
   return request(
@@ -103,6 +98,7 @@ const fetchTopLanguages = async (
   }
 
   let repoNodes = res.data.data.user.repositories.nodes;
+  /** @type {Record<string, boolean>} */
   let repoToHide = {};
   const allExcludedRepos = [...exclude_repo, ...excludeRepositories];