diff --git a/backend/package.json b/backend/package.json
index d694603..0a7ed10 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -4,7 +4,8 @@
   "main": "index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
-    "start": "nodemon --exec ts-node src/index.ts"
+    "lint": "eslint .",
+    "start": "npm run lint && nodemon --exec ts-node src/index.ts"
   },
   "keywords": [],
   "author": "raquelsr",
diff --git a/backend/src/schema/mutations/User.ts b/backend/src/schema/mutations/User.ts
index 7b28966..500b982 100644
--- a/backend/src/schema/mutations/User.ts
+++ b/backend/src/schema/mutations/User.ts
@@ -1,16 +1,16 @@
 import { GraphQLString } from 'graphql';
 import { Users } from '../../entities/Users';
-import { User } from '../types/User';
+import { CreateUserPayload, User } from '../types/User';
 
 export const CREATE_USER = {
     type: User,
     args: {
-        name: {type: GraphQLString},
-        lastName: {type: GraphQLString},
-        country: {type: GraphQLString},
-        role: {type: GraphQLString}
+        name: { type: GraphQLString },
+        lastName: { type: GraphQLString },
+        country: { type: GraphQLString },
+        role: { type: GraphQLString }
     },
-    resolve: async (_: any, args: any) => {
+    resolve: async (_: unknown, args: CreateUserPayload) => {
         const { name, lastName, country, role } = args;
 
         const result = await Users.insert({
diff --git a/backend/src/schema/queries/User.ts b/backend/src/schema/queries/User.ts
index c161f5d..855486d 100644
--- a/backend/src/schema/queries/User.ts
+++ b/backend/src/schema/queries/User.ts
@@ -1,7 +1,7 @@
 import { GraphQLList } from 'graphql';
 import { Users } from '../../entities/Users';
 import { Countries } from '../../entities/Countries';
-import { getUsersByCountrySuccessPayload, getTUsersByRoleSuccessPayload, UserRegistrationStatistics, UsersByCountry, UsersByRole, User } from '../types/User';
+import { GetUsersByCountrySuccessPayload, GetTUsersByRoleSuccessPayload, UserRegistrationStatistics, UsersByCountry, UsersByRole, User } from '../types/User';
 import { Roles } from '../../entities/Roles';
 
 
@@ -31,7 +31,7 @@ export const GET_USER_REGISTRATION_STATISTICS = {
 export const GET_USERS_BY_COUNTRY = {
     type: new GraphQLList(UsersByCountry),
     resolve: async () => {
-        const result: getUsersByCountrySuccessPayload[] = [];
+        const result: GetUsersByCountrySuccessPayload[] = [];
         const countries = await Countries.find();
         const users = await Users.find();
         countries.map(country => {
@@ -50,7 +50,7 @@ export const GET_USERS_BY_COUNTRY = {
 export const GET_USERS_BY_ROLE = {
     type: new GraphQLList(UsersByRole),
     resolve: async () => {
-        const result: getTUsersByRoleSuccessPayload[] = [];
+        const result: GetTUsersByRoleSuccessPayload[] = [];
         const roles = await Roles.find();
         const users = await Users.find();
         roles.map(role => {
diff --git a/backend/src/schema/types/User.ts b/backend/src/schema/types/User.ts
index 3b362c1..ba16cef 100644
--- a/backend/src/schema/types/User.ts
+++ b/backend/src/schema/types/User.ts
@@ -56,14 +56,21 @@ export const UsersByRole = new GraphQLObjectType({
     }
 });
 
-export type getUsersByCountrySuccessPayload = {
+export type GetUsersByCountrySuccessPayload = {
     country: string;
     totalCount: number;
     percentage: number;
 }
 
-export type getTUsersByRoleSuccessPayload = {
+export type GetTUsersByRoleSuccessPayload = {
     role: string;
     totalCount: number;
     percentage: number;
+}
+
+export type CreateUserPayload = {
+    name: string;
+    lastName: string;
+    country: string;
+    role: string;
 }
\ No newline at end of file
diff --git a/frontend/package.json b/frontend/package.json
index ff8306b..f77852f 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -23,7 +23,8 @@
     "start": "react-scripts start",
     "build": "react-scripts build",
     "test": "react-scripts test",
-    "eject": "react-scripts eject"
+    "eject": "react-scripts eject",
+    "lint": "eslint src/**/*.ts src/**/*.tsx"
   },
   "eslintConfig": {
     "extends": [
diff --git a/frontend/src/components/BarChart.tsx b/frontend/src/components/BarChart.tsx
index a4b3e1f..62810b3 100644
--- a/frontend/src/components/BarChart.tsx
+++ b/frontend/src/components/BarChart.tsx
@@ -3,7 +3,7 @@ import { BarChart as BarChartRechart, Bar, CartesianGrid, Legend, Tooltip, XAxis
 import { LayoutType } from 'recharts/types/util/types';
 
 export type BarChartProps = {
-    data: any[];
+    data: unknown[];
     dataKey: string;
     xAxisKeys?: string;
     yAxisKeys?: string;
diff --git a/frontend/src/components/LineChart.tsx b/frontend/src/components/LineChart.tsx
index 1e9c5ff..20adb41 100644
--- a/frontend/src/components/LineChart.tsx
+++ b/frontend/src/components/LineChart.tsx
@@ -2,7 +2,7 @@ import * as React from 'react';
 import { LineChart as LineChartRechart, Line, CartesianGrid, XAxis, YAxis } from 'recharts';
 
 export type LineChartProps = {
-  data: any[];
+  data: unknown[];
   dataKey: string;
   xAxisKeys: string;
 }
diff --git a/frontend/src/components/PieChart.tsx b/frontend/src/components/PieChart.tsx
index 840cd08..9a7e30f 100644
--- a/frontend/src/components/PieChart.tsx
+++ b/frontend/src/components/PieChart.tsx
@@ -2,7 +2,7 @@ import * as React from 'react';
 import { Label, LabelList, Pie, PieChart as PieChartRechart } from 'recharts';
 
 export type PieChartProps = {
-    data: any[];
+    data: unknown[];
     dataKey: string;
     nameKey: string;
 }
diff --git a/frontend/src/components/RadarChart.tsx b/frontend/src/components/RadarChart.tsx
index 6a6a25f..5efbd45 100644
--- a/frontend/src/components/RadarChart.tsx
+++ b/frontend/src/components/RadarChart.tsx
@@ -2,7 +2,7 @@ import * as React from 'react';
 import { RadarChart as RadarChartRechart, PolarAngleAxis, PolarRadiusAxis, PolarGrid, Radar, Legend } from 'recharts';
 
 type RadarChartProps = {
-    data: any[];
+    data: unknown[];
 }
 
 export const RadarChart: React.FC<RadarChartProps> = ({ data }) => {