How often should backups be taken?
It depends on how much the site changes. An e-commerce or dynamic portal needs a different frequency from a brochure site. The ability to restore matters just as much.
What do you monitor?
Uptime, SSL, errors, space, resources, forms, anomalies, updates and the critical aspects agreed for the project.
Are updates always necessary?
Yes, but they have to be handled with judgement. Updating reduces risk, though on complex sites it may require testing or staging.
Does maintenance include changes to the site?
It can include small changes and ongoing support, where agreed. It is a different thing from a redesign or the development of large new features.
What happens if the site goes offline?
With monitoring and clear procedures the problem is spotted sooner, the cause is assessed and action is taken on hosting, code, DNS, SSL or a restore.
Is it needed even if the site was just rebuilt?
Yes. Right after launch is when updates, real traffic, forms, campaigns and potential weak points all begin.