Do I need to have existing tech in place before we start?

Starting from an existing setup is also fine and simply includes an extra step. Before anything gets built, what exists gets audited: what you have, who owns it, what it costs, and whether it is doing anything. That audit routinely finds subscriptions nobody uses, a domain registered under somebody else's account, analytics that was never installed properly or is recording nothing useful, and two tools doing the same job. Sorting that out is frequently the highest value work in the first month, and none of it is glamorous.

The thing worth knowing is that existing setups carry ownership questions. If a previous contractor registered your domain, created your advertising account, or built your site on a platform only they can host, you may not control assets you believe you own. That is worth establishing early, because it is much easier to resolve while the relationship is cordial than after it has ended. The first question in any audit is not what do you have, it is whose name is it in.

What you do need before starting is less about technology and more about information. A clear sense of who your customer is, or at least an honest description of who has bought so far. What you charge. Where the work has come from to date. Those answers shape everything technical, and no amount of infrastructure compensates for not having them.

If you have nothing at all and are not sure where to begin, that is a normal starting point rather than a disadvantage. The sequence is the same either way, it just has fewer steps that involve undoing something.

If you have accumulated tools already, the audit frequently finds duplication rather than absence. Two things doing the same job because the second was bought before anybody checked, a subscription from a project that ended, or a free tier of something nobody has opened. Removing those is usually the first month's most valuable work and it costs nothing, which makes it an unusual starting point for an engagement.

What genuinely slows a start is not missing technology but missing decisions. Not knowing what you charge, who you serve, or what you are actually selling will stall a website build regardless of what infrastructure exists. Those questions get asked early for that reason, and answering them roughly is sufficient to proceed while leaving them unanswered is not.