I currently have an EC2 instance up and running with Amazon Linux running and transferred my project (which contains both React/NodeJS/Express) onto the EC2 instance via SFTP using FileZilla.

For the EC2’s Security Groups, I opened a port for 3000 (protocol: tcp, source: 0.0.0.0/0), which is how my Express is defined as well.

So I sshed into EC2 instance and ran the project’s Express, and sees it listening to port 3000 within the terminal. But once I hit the Public DNS with ec2...us-west-1.compute.amazonaws.com:3000, it says The site can’t be reached – ec2…us-west-1.compute.amazonaws.com took too late to respond.

What could be the issue and how can I go about from here to connect to it?

Thank you in advance and will upvote/accept answer.

You may be encountering an issue with outbound traffic. You may be inside a company’s network, either physically connected or VPN’d in. In some instances, your VPN isnt set up to handle split traffic, so you must abide by your company’s outbound restrictions.

In a situation like this, you would want to use a proxy to access your site. when locking down your security group, make sure you use your proxy’s public IP (not your company’s).