Node App Deployment on Vercel giving a Not Found error

Question

I'm trying to create a small hobby project to scrape real time stock prices using a simple NodeJS app.

I came across a couple of posts online saying Vercel would be a good platform to host a free tier and I was trying it out, but I keep seeing Not Found errors.

Would you guys know how to make this work? Will appreciate any help!

Folder structure:

├── api
│   └── index.ts
├── src
│   ├── api
│   │   └── router.ts
│   │   └── ...more_files
│   ├── config.ts
│   ├── scraper
│   │   └── script.ts
│   │   └── ...more_files
│   │   └── page.html (To render on one specific endpoint)
├── vercel.json
├── package.json
├── tsconfig.json

index.ts:

import express from "express";
import cors from "cors";
import * as CONFIG from "../src/config";
import { startUp, daily, dailyEx, quote, quoteEx } from "../src/scraper/script";
import cron from 'node-cron';
import bodyParser from 'body-parser';
import router from "../src/api/router";

const app = express();
app.use(bodyParser.json());
app.use(cors({ origin: "*" }));
app.use("/", router);

const HOST = CONFIG.HOST;
const PORT = parseInt(CONFIG.PORT);

const assets = startUp();
export const quoteArgs = quote.bind(null, assets);

cron.schedule(dailyEx, daily, {
    timezone: 'Etc/UTC'
});

cron.schedule(quoteEx, quoteArgs, {
    timezone: 'Etc/UTC'
});

export default app;

package.json:

{
  "name": "stock-analyzer",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "clean": "rimraf build",
    "build": "npm run clean && tsc",
    "start": "npm run build && node build/api/index.js"
  },
  "dependencies": {
    "body-parser": "^1.20.2",
    "cors": "^2.8.5",
    "dotenv": "^16.4.5",
    "express": "^4.19.2",
    "fs": "^0.0.1-security",
    "h5wasm": "^0.7.5",
    "node-cron": "^3.0.3",
    "rimraf": "^5.0.8",
    "serverless-http": "^3.2.0",
    "yahoo-finance2": "^2.11.3"
  },
  "devDependencies": {
    "@types/node": "20.14.10",
    "typescript": "5.5.3"
  }
}

tsconfig:

{
  "compilerOptions": {
    "lib": [
      "es6"
    ],
    "target": "es6",
    "module": "commonjs",
    "moduleResolution": "node",
    "outDir": "./build",
    "rootDir": ".",
    "experimentalDecorators": true,
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "noImplicitAny": false
  },
  "include": [
    "src/**/*.ts",
    "api/**/*.ts"
  ]
}

vercel.json:

{
    "version": 2,
    "builds": [
      {
        "src": "build/api/index.js",
        "use": "@vercel/node"
      }
    ],
    "routes": [
      {
        "src": "/(.*)",
        "dest": "build/api/index.js"
      }
    ],
    "buildCommand": "npm run build"
  }

I've been stumped with what isn't working and tried a bunch of things.

This is the Vercel error I get, although there are no errors on deployment logs.