diff --git a/modulo4/projeto-todolist-backend/.gitignore b/modulo4/projeto-todolist-backend/.gitignore
new file mode 100644
index 0000000..8f5e467
--- /dev/null
+++ b/modulo4/projeto-todolist-backend/.gitignore
@@ -0,0 +1,3 @@
+node_modules
+package-lock.json
+.env
\ No newline at end of file
diff --git a/modulo4/projeto-todolist-backend/package.json b/modulo4/projeto-todolist-backend/package.json
new file mode 100644
index 0000000..de12877
--- /dev/null
+++ b/modulo4/projeto-todolist-backend/package.json
@@ -0,0 +1,14 @@
+{
+  "name": "projeto-todolist-backend",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "tsc && node ./build/app.js",
+    "dev": "ts-node-dev ./src/app.ts",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "Pablo Leão",
+  "license": "ISC"
+}
\ No newline at end of file
diff --git a/modulo4/projeto-todolist-backend/src/app.ts b/modulo4/projeto-todolist-backend/src/app.ts
new file mode 100644
index 0000000..c13a534
--- /dev/null
+++ b/modulo4/projeto-todolist-backend/src/app.ts
@@ -0,0 +1,176 @@
+import express from 'express';
+import cors from 'cors';
+import { AddressInfo } from 'net';
+import { connection } from './connection';
+
+const app = express();
+app.use(express.json());
+app.use(cors());
+
+const cyan = '\u001b[36m';
+const white = '\u001b[37m';
+
+function formataDataDate(data: string): Date {
+    const arrayDataString = data.split('/');
+    const arrayDataNumber = [Number(arrayDataString[2]), Number(arrayDataString[1]) - 1, Number(arrayDataString[0])];
+    const dataFormatada = new Date(arrayDataNumber[0], arrayDataNumber[1], arrayDataNumber[2]);
+    return dataFormatada;
+}
+
+app.get('/user/:id', async (req, res) => {
+    const id = req.params.id;
+    try {
+        const result = await connection
+            .from("ToDoListUser")
+            .select("id", "nickname")
+            .where("id", id);
+        
+        if (result.length === 0) {
+            throw new Error("Usuário não encontrado!");
+        }
+        
+        res.status(200).send(result[0]);
+
+    } catch (error: any) {
+        switch(error.message) {
+            case "Usuário não encontrado!":
+                res.status(404).send({ message: error.message });
+                break;
+            default:
+                res.status(500).send(error.sqlMessage || error.message);
+                break;
+        }   
+    }
+})
+
+app.get('/task/:id', async (req, res) => {
+    const id = req.params.id;
+    try {
+        const result = await connection("ToDoListTask")
+            .where("id", id);
+        
+        if (result.length === 0) {
+            throw new Error("Tarefa não encontrada!");
+        }
+        
+        res.status(200).send({...result[0], limit_date: result[0].limit_date.toLocaleDateString('pt-BR')});
+
+    } catch (error: any) {
+        switch(error.message) {
+            case "Tarefa não encontrada!":
+                res.status(404).send({ message: error.message });
+                break;
+            default:
+                res.status(500).send(error.sqlMessage || error.message);
+                break;
+        }   
+    }
+})
+
+app.post('/user', async (req, res) => {
+    const { username, nickname, email } = req.body;
+
+    try {
+        if (!username || !nickname || !email) {
+            throw new Error("Todos os campos devem ser preenchidos. Verifique os campos username, nickname e email.")
+        }
+
+        await connection("ToDoListUser")
+            .insert({
+                id: Date.now().toString(),
+                username: username,
+                nickname: nickname,
+                email: email
+            });
+        res.status(201).send("Usuário criado com sucesso!");
+
+    } catch (error: any) {
+        switch (error.message) {
+            case "Todos os campos devem ser preenchidos. Verifique os campos username, nickname e email.":
+                res.status(422).send({ message: error.message });
+                break;
+            default:
+                res.status(500).send(error.sqlMessage || error.message);
+                break;
+        }
+    }
+});
+
+app.post('/task', async (req, res) => {
+    const { title, description, limitDate, creatorUserId } = req.body
+
+    try {
+        if (!title || ! description || !limitDate || !creatorUserId) {
+            throw new Error("Todos os campos devem ser preenchidos. Verifique os campos title, description, limitDate e creatorUserId.")
+        }     
+
+        await connection("ToDoListTask")
+            .insert({
+                id: `${Date.now().toString()}task`,
+                title: title,
+                description: description,
+                limit_date: formataDataDate(limitDate),
+                creator_user_id: creatorUserId
+            });
+        res.status(201).send("Tarefa criada com sucesso!");
+
+    } catch (error: any) {
+        switch (error.message) {
+            case "Todos os campos devem ser preenchidos. Verifique os campos title, description, limitDate e creatorUserId.":
+                res.status(422).send({ message: error.message });
+                break;
+            default:
+                res.status(500).send(error.sqlMessage || error.message);
+                break;
+        }
+    }
+})
+
+app.put('/user/edit/:id', async (req, res) => {
+    const id = req.params.id;
+    const { username, nickname } = req.body;
+
+    try {
+        if (!id || !username || !nickname) {
+            throw new Error("Todos os campos devem ser preenchidos. Verifique os campos id, username e nickname.");
+        }
+        const findUser = await connection
+            .from("ToDoListUser")
+            .select("id")
+            .where("id", id);
+        
+        if (findUser.length === 0) {
+            throw new Error("Não existe usuário com o id inserido!");
+        }
+        await connection("ToDoListUser")
+            .update({
+                username: username,
+                nickname: nickname
+            })
+            .where("id", id);
+        
+        res.status(200).send("Usuário editado com sucesso!");
+
+    } catch (error: any) {
+        switch (error.message) {
+            case "Não existe usuário com o id inserido!":
+                res.status(404).send({ message: error.message });
+                break;
+            case "Todos os campos devem ser preenchidos. Verifique os campos id, username e nickname.":
+                res.status(422).send({ message: error.message });
+                break;
+            default:
+                res.status(500).send(error.sqlMessage || error.message);
+                break;
+        }
+    }
+})
+
+const server = app.listen(3003, () => {
+    if (server) {
+        const address = server.address() as AddressInfo;
+        console.log(`${cyan}Server is running at http://localhost:${address.port}${white}`);
+    } else {
+        console.log("Failure upon starting server");
+    }
+});
\ No newline at end of file
diff --git a/modulo4/projeto-todolist-backend/src/connection.ts b/modulo4/projeto-todolist-backend/src/connection.ts
new file mode 100644
index 0000000..0db5bd7
--- /dev/null
+++ b/modulo4/projeto-todolist-backend/src/connection.ts
@@ -0,0 +1,15 @@
+import knex from 'knex';
+import dotenv from 'dotenv';
+
+dotenv.config();
+export const connection = knex({
+   client: "mysql",
+   connection: {
+       host: process.env.DB_HOST,
+       port: 3306,
+       user: process.env.DB_USER,
+       password: process.env.DB_PASSWORD,
+       database: process.env.DB_SCHEMA,
+       multipleStatements: true
+   }
+});
\ No newline at end of file
diff --git a/modulo4/projeto-todolist-backend/tsconfig.json b/modulo4/projeto-todolist-backend/tsconfig.json
new file mode 100644
index 0000000..467c88a
--- /dev/null
+++ b/modulo4/projeto-todolist-backend/tsconfig.json
@@ -0,0 +1,14 @@
+{
+    "compilerOptions": {
+       "target": "es6",
+       "module": "commonjs",
+       "sourceMap": true,
+       "outDir": "./build",
+       "rootDir": "./src",
+       "removeComments": true,
+       "strict": true,
+       "noImplicitAny": true,
+       "esModuleInterop": true,
+       "forceConsistentCasingInFileNames": true
+    }
+ }
\ No newline at end of file