[ISSUE] Express+Mongo API backend Not working on Vercel

[sagnikpal]

I deployed a basic Express Hello world app on vercel & it worked fine. https://hello-world-vercel-tawny.vercel.app/

However, the next complex app failed to go online. https://genius-tools-backend.vercel.app/
I created an Express API server with MogoDB cloud connection. I used typescript.

The APIs are working fine locally, but when I deploy on vercel it shows 404 error on vercel dashboard.

I configured the Mong_URI in the vercel env variables section. Then did the deployment.

Blockquote
Build logs
[22:42:13.559] Cloning github.com/sagnikpal/genius-tools-backend (Branch: master, Commit: b540bed)
[22:42:13.580] Skipping build cache, deployment was triggered without cache.
[22:42:13.955] Cloning completed: 396.000ms
[22:42:14.202] Running build in Washington, D.C., USA (East) – iad1
[22:42:14.379] Running “vercel build”
[22:42:14.833] Vercel CLI 41.3.2
[22:42:14.946] WARN! Due to builds existing in your configuration file, the Build and Development Settings defined in your Project Settings will not apply. Learn More: Error List
[22:42:14.962] Build Completed in /vercel/output [12ms]
[22:42:14.978] Deploying outputs…
[22:42:15.829]
[22:42:15.963] Deployment completed
[22:42:16.448] Uploading build cache [4.00 kB]…
[22:42:16.545] Build cache uploaded: 96.944ms
Blockquote

There are no erors in runtime logs either

Any help would be highly appreciated.

[system]

There’s another community post with 404 debugging tips that might be helpful. Please give these solutions a try and let us know how it goes.

Debugging 404 Errors

Sometimes things don’t go as expected when deploying a website. If you see a 404 on your site, that means the page or resource couldn’t be found. There are many possible causes, and the absence of something can be tricky debug if you don’t know where to look. Here are some things you can do to find the cause and fix it. Debugging Tips Check the error code If you see a mostly white screen with 404: NOT_FOUND along with a Code and and ID then you can click the blue info box below the error deta…

A human should be around soon to offer more advice. But you can also get helpful information quickly by asking v0.

If you’re having trouble deploying an Express app, this guide can help.

How to Deploy an Express.js Application to Vercel

You can also ask v0 for suggestions tailored to your own project setup.