Hey, as part of my deployment, I need to run some code every time I create / replace a specific ec2 instance. I have not found the api to do so, I was expecting some kind of lifecycle event such as:

let instance = new aws.ec2.Instance( ......);
instance.onReplace((_) => {myCodeHere;})

Is this possible with Pulumi ?

You can use the Pulumi Command provider: https://www.pulumi.com/registry/packages/command/