diff --git a/.env.production b/.env.production
index 8cabc5a..e729e7c 100644
--- a/.env.production
+++ b/.env.production
@@ -1,2 +1,6 @@
 CREDENTIALS_ENABLED = 1
+CREDENTIALS_PATH = /home/ubuntu/.certbot/config/live/algorithm-visualizer.org
+CREDENTIALS_CA = fullchain.pem
+CREDENTIALS_KEY = privkey.pem
+CREDENTIALS_CERT = cert.pem
 WEBHOOK_ENABLED = 1
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..dbd56dc
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,54 @@
+# Contributing
+
+> #### Table of Contents
+> - [Running Locally](#running-locally)
+> - [Directory Structure](#directory-structure)
+
+Are you a first-timer in contributing to open source? [These guidelines](https://opensource.guide/how-to-contribute/#how-to-submit-a-contribution) from GitHub might help!
+
+## Running Locally
+
+1. Fork this repository.
+
+2. Clone your forked repo to your machine.
+
+    ```bash
+    git clone https://github.com/<your-username>/server.git    
+    ```
+
+3. Install [Docker](https://docs.docker.com/install/), if not done already.
+
+4. Create `.env.local` in the project root:
+    ```bash
+    # By putting dummy values, GitHub sign in will not work locally
+    GITHUB_CLIENT_ID = dummy
+    GITHUB_CLIENT_SECRET = dummy
+
+    # By putting dummy values, extracting visualizing commands will not work locally (except for JavaScript).
+    AWS_ACCESS_KEY_ID = dummy
+    AWS_SECRET_ACCESS_KEY = dummy
+    ```
+
+5. Install dependencies, and run the server.
+
+    ```bash
+    cd server
+
+    npm install
+    
+    npm run watch
+    ```
+    
+6. Open [`http://localhost:8080/`](http://localhost:8080/) in a web browser.
+
+## Directory Structure
+
+- [**src/**](src) contains source code. 
+    - [**config/**](src/config) contains configuration files.
+    - [**controllers/**](src/controllers) routes and processes incoming requests.
+    - [**middlewares/**](src/middlewares) contains Express middlewares.
+    - [**models/**](src/models) manages algorithm visualizations and their hierarchy.
+    - [**tracers/**](src/tracers) build visualization libraries and compiles/runs code.
+    - [**utils/**](src/utils) contains utility files.
+
+**NOTE** that for JavaScript, it builds a web worker rather than a docker image. Once a browser fetches the web worker, it will submit users' code to the web worker locally, instead of submitting to the remote server, to extract visualizing commands.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..2a52e6b
--- /dev/null
+++ b/README.md
@@ -0,0 +1,9 @@
+# Server
+
+> This repository is part of the project [Algorithm Visualizer](https://github.com/algorithm-visualizer).
+
+`server` serves [`algorithm-visualizer`](https://github.com/algorithm-visualizer/algorithm-visualizer) and provides APIs that the web app needs on the fly. (e.g., GitHub sign in, compiling/running code, etc.)
+
+## Contributing
+
+Check out the [contributing guidelines](https://github.com/algorithm-visualizer/server/blob/master/CONTRIBUTING.md).
diff --git a/certbot.ini b/certbot.ini
new file mode 100644
index 0000000..dab450e
--- /dev/null
+++ b/certbot.ini
@@ -0,0 +1,7 @@
+config-dir = /home/ubuntu/.certbot/config
+work-dir = /home/ubuntu/.certbot/work
+logs-dir = /home/ubuntu/.certbot/logs
+email = parkjs814@gmail.com
+authenticator = webroot
+webroot-path = /home/ubuntu/server/public/frontend-built
+domains = algorithm-visualizer.org
diff --git a/package-lock.json b/package-lock.json
index ea58289..80b8362 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -112,6 +112,12 @@
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       "dev": true
     },
+    "@types/node-cron": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/@types/node-cron/-/node-cron-3.0.1.tgz",
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+    },
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       "integrity": "sha1-ml9pkFGx5wczKPKgCJaLZOopVdI="
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+      "resolved": "https://registry.npmjs.org/aws-sdk/-/aws-sdk-2.814.0.tgz",
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+      "requires": {
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+        "events": "1.1.1",
+        "ieee754": "1.1.13",
+        "jmespath": "0.15.0",
+        "querystring": "0.2.0",
+        "sax": "1.2.1",
+        "url": "0.10.3",
+        "uuid": "3.3.2",
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-        "is-buffer": "^2.0.2"
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@@ -213,6 +234,11 @@
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+    },
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@@ -258,6 +284,16 @@
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+    "events": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/events/-/events-1.1.1.tgz",
+      "integrity": "sha1-nr23Y1rQmccNzEwqH1AEKI6L2SQ="
+    },
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@@ -711,6 +741,11 @@
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@@ -919,6 +959,19 @@
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+        "moment": ">= 2.9.0"
+      }
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+      }
+    },
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@@ -1091,11 +1152,21 @@
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diff --git a/package.json b/package.json
index 22904c9..d33045a 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,8 @@
 {
   "name": "@algorithm-visualizer/server",
   "version": "2.0.0",
-  "description": "Server for Algorithm Visualizer",
+  "title": "Algorithm Visualizer",
+  "description": "Algorithm Visualizer is an interactive online platform that visualizes algorithms from code.",
   "scripts": {
     "watch": "NODE_ENV=development NODE_PATH=src ts-node-dev --respawn --ignore-watch node_modules --no-notify src",
     "start": "NODE_ENV=production NODE_PATH=src ts-node --transpile-only src",
@@ -19,13 +20,15 @@
     "@types/fs-extra": "^7.0.0",
     "@types/morgan": "^1.7.35",
     "@types/node": "^12.0.0",
+    "@types/node-cron": "^3.0.1",
     "@types/remove-markdown": "^0.1.1",
     "@types/uuid": "^3.4.4",
     "ts-node-dev": "^1.0.0-pre.39",
     "tslint": "^5.16.0"
   },
   "dependencies": {
-    "axios": "^0.19.0",
+    "aws-sdk": "^2.814.0",
+    "axios": "^0.21.2",
     "body-parser": "^1.18.2",
     "compression": "^1.7.3",
     "dotenv": "^8.0.0",
@@ -34,6 +37,7 @@
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     "fs-extra": "^6.0.1",
     "morgan": "^1.9.1",
+    "node-cron": "^3.0.0",
     "remove-markdown": "^0.3.0",
     "ts-httpexceptions": "^4.1.0",
     "ts-node": "^8.1.0",
diff --git a/pm2.json b/pm2.json
new file mode 100644
index 0000000..9450d37
--- /dev/null
+++ b/pm2.json
@@ -0,0 +1,8 @@
+{
+  "apps": [
+    {
+      "name": "algorithm-visualizer",
+      "script": "npm start"
+    }
+  ]
+}
diff --git a/src/Server.ts b/src/Server.ts
index ad9d1d0..637b2df 100644
--- a/src/Server.ts
+++ b/src/Server.ts
@@ -7,18 +7,19 @@ import compression from 'compression';
 import { __PROD__, credentials, httpPort, httpsPort, webhookOptions } from 'config/environments';
 import http from 'http';
 import https from 'https';
+import cron from 'node-cron';
 import { Hierarchy } from 'models';
 import * as Tracers from 'tracers';
 import { errorHandlerMiddleware, frontendMiddleware, redirectMiddleware } from 'middlewares';
-import { execute, pull } from 'utils/misc';
+import { execute, issueHttpsCertificate, pull } from 'utils/misc';
 import { frontendBuildDir, frontendBuiltDir, frontendDir, rootDir } from 'config/paths';
 
 const Webhook = require('express-github-webhook');
 
 export default class Server {
-  private readonly app = express();
   readonly hierarchy = new Hierarchy();
   readonly tracers = Object.values(Tracers).map(Tracer => new Tracer());
+  private readonly app = express();
   private readonly webhook = webhookOptions && Webhook(webhookOptions);
 
   constructor() {
@@ -27,17 +28,17 @@ export default class Server {
       .use(morgan(__PROD__ ? 'tiny' : 'dev'))
       .use(redirectMiddleware())
       .use(bodyParser.json())
-      .use(bodyParser.urlencoded({extended: true}))
+      .use(bodyParser.urlencoded({ extended: true }))
       .use('/api', this.getApiRouter())
       .use(frontendMiddleware(this));
     if (this.webhook) {
-      this.app.use('/webhook', this.webhook);
+      this.app.use(this.webhook);
     }
     this.app.use(errorHandlerMiddleware());
 
     if (this.webhook) {
       this.webhook.on('push', async (repo: string, data: any) => {
-        const {ref, head_commit} = data;
+        const { ref, head_commit } = data;
         if (ref !== 'refs/heads/master') return;
         if (!head_commit) throw new Error('The `head_commit` is empty.');
 
@@ -62,6 +63,12 @@ export default class Server {
         await tracer.update(data.release);
       });
     }
+
+    if (credentials) {
+      cron.schedule('0 0 1 * *', () => {
+        issueHttpsCertificate();
+      });
+    }
   }
 
   getApiRouter() {
@@ -75,7 +82,11 @@ export default class Server {
 
   async update(commit?: string) {
     await pull(rootDir, 'server', commit);
-    await execute('npm install', {cwd: rootDir});
+    await execute('npm install', {
+      cwd: rootDir,
+      stdout: process.stdout,
+      stderr: process.stderr,
+    });
     process.exit(0);
   };
 
@@ -86,7 +97,11 @@ export default class Server {
       'npm run build',
       `rm -rf ${frontendBuiltDir}`,
       `mv ${frontendBuildDir} ${frontendBuiltDir}`,
-    ].join(' && '), {cwd: frontendDir});
+    ].join(' && '), {
+      cwd: frontendDir,
+      stdout: process.stdout,
+      stderr: process.stderr,
+    });
   }
 
   start() {
diff --git a/src/config/environments.ts b/src/config/environments.ts
index 0a8ae31..912d9c8 100644
--- a/src/config/environments.ts
+++ b/src/config/environments.ts
@@ -1,15 +1,10 @@
 import fs from 'fs';
 import { ServerOptions } from 'https';
 import path from 'path';
+import { issueHttpsCertificate } from '../utils/misc';
 
 require('dotenv-flow').config();
 
-declare var process: {
-  env: {
-    [key: string]: string,
-  }
-};
-
 const {
   NODE_ENV,
 
@@ -27,7 +22,12 @@ const {
 
   GITHUB_CLIENT_ID,
   GITHUB_CLIENT_SECRET,
-} = process.env;
+
+  AWS_ACCESS_KEY_ID,
+  AWS_SECRET_ACCESS_KEY,
+} = process.env as {
+  [key: string]: string,
+};
 
 const isEnabled = (v: string) => v === '1';
 
@@ -48,6 +48,8 @@ const missingVars = [
   ] : []),
   'GITHUB_CLIENT_ID',
   'GITHUB_CLIENT_SECRET',
+  'AWS_ACCESS_KEY_ID',
+  'AWS_SECRET_ACCESS_KEY',
 ].filter(variable => process.env[variable] === undefined);
 if (missingVars.length) throw new Error(`The following environment variables are missing: ${missingVars.join(', ')}`);
 
@@ -62,12 +64,22 @@ export const webhookOptions = isEnabled(WEBHOOK_ENABLED) ? {
   secret: WEBHOOK_SECRET,
 } : undefined;
 
-const readCredentials = (file: string) => fs.readFileSync(path.resolve(CREDENTIALS_PATH, file));
-export const credentials: ServerOptions | undefined = isEnabled(CREDENTIALS_ENABLED) ? {
-  ca: readCredentials(CREDENTIALS_CA),
-  key: readCredentials(CREDENTIALS_KEY),
-  cert: readCredentials(CREDENTIALS_CERT),
-} : undefined;
+export let credentials: ServerOptions | undefined;
+if (isEnabled(CREDENTIALS_ENABLED)) {
+  if (fs.existsSync(CREDENTIALS_PATH)) {
+    const readCredentials = (file: string) => fs.readFileSync(path.resolve(CREDENTIALS_PATH, file));
+    credentials = {
+      ca: readCredentials(CREDENTIALS_CA),
+      key: readCredentials(CREDENTIALS_KEY),
+      cert: readCredentials(CREDENTIALS_CERT),
+    };
+  } else {
+    issueHttpsCertificate();
+  }
+}
 
 export const githubClientId = GITHUB_CLIENT_ID;
 export const githubClientSecret = GITHUB_CLIENT_SECRET;
+
+export const awsAccessKeyId = AWS_ACCESS_KEY_ID;
+export const awsSecretAccessKey = AWS_SECRET_ACCESS_KEY;
diff --git a/src/middlewares/errorHandlerMiddleware.ts b/src/middlewares/errorHandlerMiddleware.ts
index 8a1936a..8eeb830 100644
--- a/src/middlewares/errorHandlerMiddleware.ts
+++ b/src/middlewares/errorHandlerMiddleware.ts
@@ -8,7 +8,7 @@ export function errorHandlerMiddleware() {
       err = new InternalServerError(err.message, err);
     }
 
-    const {name, message, status} = err;
-    res.status(status).json({name, message, status});
+    const {message, status} = err;
+    res.status(status).send(message);
   };
 }
diff --git a/src/tracers/DockerTracer.ts b/src/tracers/DockerTracer.ts
index b3d5e27..3672e2f 100644
--- a/src/tracers/DockerTracer.ts
+++ b/src/tracers/DockerTracer.ts
@@ -15,13 +15,15 @@ export class DockerTracer extends Tracer {
     super(lang);
     this.directory = path.resolve(__dirname, lang);
     this.imageName = `tracer-${this.lang}`;
-
-    this.build = this.build.bind(this);
   }
 
   build(release: Release) {
     const {tag_name} = release;
-    return execute(`docker build -t ${this.imageName} . --build-arg tag_name=${tag_name}`, {cwd: this.directory});
+    return execute(`docker build -t ${this.imageName} . --build-arg tag_name=${tag_name}`, {
+      cwd: this.directory,
+      stdout: process.stdout,
+      stderr: process.stderr,
+    });
   }
 
   route(router: express.Router) {
diff --git a/src/tracers/LambdaTracer.ts b/src/tracers/LambdaTracer.ts
new file mode 100644
index 0000000..b608a45
--- /dev/null
+++ b/src/tracers/LambdaTracer.ts
@@ -0,0 +1,33 @@
+import AWS from 'aws-sdk';
+import express from 'express';
+import { Release, Tracer } from 'tracers/Tracer';
+import { awsAccessKeyId, awsSecretAccessKey } from 'config/environments';
+import { BadRequest } from 'ts-httpexceptions';
+
+export class LambdaTracer extends Tracer {
+  static lambda = new AWS.Lambda({
+    region: 'us-east-2',
+    accessKeyId: awsAccessKeyId,
+    secretAccessKey: awsSecretAccessKey,
+  });
+
+  async build(release: Release) {
+  }
+
+  route(router: express.Router) {
+    router.post(`/${this.lang}`, (req, res, next) => {
+      const {code} = req.body;
+      LambdaTracer.lambda.invoke({
+        FunctionName: `extractor-${this.lang}`,
+        InvocationType: 'RequestResponse',
+        Payload: JSON.stringify(code),
+      }, function (err, data) {
+        if (err) return next(err);
+        if (typeof data.Payload !== 'string') return next(new Error('Unexpected Payload Type'));
+        const payload = JSON.parse(data.Payload);
+        if (!payload.success) return next(new BadRequest(payload.errorMessage));
+        res.send(payload.commands);
+      });
+    });
+  }
+}
diff --git a/src/tracers/java/Dockerfile b/src/tracers/java/Dockerfile
deleted file mode 100644
index 8aabc07..0000000
--- a/src/tracers/java/Dockerfile
+++ /dev/null
@@ -1,8 +0,0 @@
-FROM openjdk:8
-
-ARG tag_name
-
-RUN curl --create-dirs -o /usr/local/lib/algorithm-visualizer.jar -L "https://github.com/algorithm-visualizer/tracers.java/releases/download/${tag_name}/algorithm-visualizer.jar"
-
-CMD javac -cp /usr/local/lib/algorithm-visualizer.jar Main.java \
- && java -cp /usr/local/lib/algorithm-visualizer.jar:. Main
diff --git a/src/tracers/java/JavaTracer.ts b/src/tracers/java/JavaTracer.ts
index 043c3c6..e4e5f2b 100644
--- a/src/tracers/java/JavaTracer.ts
+++ b/src/tracers/java/JavaTracer.ts
@@ -1,6 +1,6 @@
-import { DockerTracer } from 'tracers/DockerTracer';
+import { LambdaTracer } from 'tracers/LambdaTracer';
 
-export class JavaTracer extends DockerTracer {
+export class JavaTracer extends LambdaTracer {
   constructor() {
     super('java');
   }
diff --git a/src/tracers/js/JsTracer.ts b/src/tracers/js/JsTracer.ts
index b253a92..a798816 100644
--- a/src/tracers/js/JsTracer.ts
+++ b/src/tracers/js/JsTracer.ts
@@ -1,26 +1,27 @@
 import path from 'path';
-import { download } from 'utils/misc';
 import { Release, Tracer } from 'tracers/Tracer';
 import express from 'express';
-import { publicDir } from 'config/paths';
 
 export class JsTracer extends Tracer {
-  readonly tracerPath: string;
   readonly workerPath: string;
+  tagName?: string;
 
   constructor() {
     super('js');
-    this.tracerPath = path.resolve(publicDir, 'algorithm-visualizer.js');
     this.workerPath = path.resolve(__dirname, 'worker.js');
   }
 
-  build(release: Release) {
+  async build(release: Release) {
     const {tag_name} = release;
-    return download(`https://github.com/algorithm-visualizer/tracers.js/releases/download/${tag_name}/algorithm-visualizer.js`, this.tracerPath);
+    this.tagName = tag_name;
   }
 
   route(router: express.Router) {
-    router.get(`/${this.lang}`, (req, res) => res.sendFile(this.tracerPath));
+    router.get(`/${this.lang}`, (req, res) => {
+      if (!this.tagName) throw new Error('JsTracer has not been built yet.');
+      const version = this.tagName.slice(1);
+      res.redirect(`https://unpkg.com/algorithm-visualizer@${version}/dist/algorithm-visualizer.umd.js`);
+    });
     router.get(`/${this.lang}/worker`, (req, res) => res.sendFile(this.workerPath));
   }
 }
diff --git a/src/utils/misc.ts b/src/utils/misc.ts
index 6074ad2..1b5fe67 100644
--- a/src/utils/misc.ts
+++ b/src/utils/misc.ts
@@ -3,10 +3,12 @@ import fs from 'fs-extra';
 import { File } from 'models';
 import removeMarkdown from 'remove-markdown';
 import * as child_process from 'child_process';
-import { ExecOptions } from 'child_process';
+import { ExecOptions, spawn } from 'child_process';
+import { rootDir } from '../config/paths';
+import path from 'path';
 
 export function download(url: string, localPath: string) {
-  return axios({url, method: 'GET', responseType: 'stream'})
+  return axios({ url, method: 'GET', responseType: 'stream' })
     .then(response => new Promise((resolve, reject) => {
       const writer = fs.createWriteStream(localPath);
       writer.on('finish', resolve);
@@ -17,11 +19,22 @@ export function download(url: string, localPath: string) {
 
 export async function pull(dir: string, repo: string, commit = 'origin/master') {
   if (fs.pathExistsSync(dir)) {
-    await execute(`git fetch`, {cwd: dir});
+    await execute(`git fetch`, {
+      cwd: dir,
+      stdout: process.stdout,
+      stderr: process.stderr,
+    });
   } else {
-    await execute(`git clone https://github.com/algorithm-visualizer/${repo}.git ${dir}`);
+    await execute(`git clone https://github.com/algorithm-visualizer/${repo}.git ${dir}`, {
+      stdout: process.stdout,
+      stderr: process.stderr,
+    });
   }
-  await execute(`git reset --hard ${commit}`, {cwd: dir});
+  await execute(`git reset --hard ${commit}`, {
+    cwd: dir,
+    stdout: process.stdout,
+    stderr: process.stderr,
+  });
 }
 
 export function getDescription(files: File[]) {
@@ -30,7 +43,7 @@ export function getDescription(files: File[]) {
   const lines = readmeFile.content.split('\n');
   lines.shift();
   while (lines.length && !lines[0].trim()) lines.shift();
-  let descriptionLines = [];
+  const descriptionLines = [];
   while (lines.length && lines[0].trim()) descriptionLines.push(lines.shift());
   return removeMarkdown(descriptionLines.join(' '));
 }
@@ -38,9 +51,9 @@ export function getDescription(files: File[]) {
 type ExecuteOptions = ExecOptions & {
   stdout?: NodeJS.WriteStream;
   stderr?: NodeJS.WriteStream;
-}
+};
 
-export function execute(command: string, {stdout, stderr, ...options}: ExecuteOptions = {}): Promise<string> {
+export function execute(command: string, { stdout, stderr, ...options }: ExecuteOptions = {}): Promise<string> {
   return new Promise((resolve, reject) => {
     const child = child_process.exec(command, options, (error, stdout, stderr) => {
       if (error) return reject(error.code ? new Error(stderr) : error);
@@ -50,3 +63,18 @@ export function execute(command: string, {stdout, stderr, ...options}: ExecuteOp
     if (child.stderr && stderr) child.stderr.pipe(stderr);
   });
 }
+
+export function issueHttpsCertificate() {
+  const certbotIniPath = path.resolve(rootDir, 'certbot.ini');
+  const childProcess = spawn('certbot', ['certonly', '--non-interactive', '--agree-tos', '--config', certbotIniPath]);
+  childProcess.stdout.pipe(process.stdout);
+  childProcess.stderr.pipe(process.stderr);
+  childProcess.on('error', console.error);
+  childProcess.on('exit', code => {
+    if (code === 0) {
+      process.exit(0);
+    } else {
+      console.error(new Error(`certbot failed with exit code ${code}.`));
+    }
+  });
+}

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