Site down - Internal Server Error

Hi. All of a sudden my site puregainz.co.uk has started to get 500s Internal Server Error on all functions. The site hasn’t been changed for over a week, and everything was fine until yesterday (Sat 16th) morning.

I’ve tried to redeploy but that hasn’t fixed it. I’m assuming something has changed at the backend. Please could you let me know how I get my site back online. Thanks.

I noticed in the deployment logs that the node version was increased which broke my site. Nice!