Personalization?

It's very difficult to identify the type of prospect when a visitor first comes to the website

Few websites do it based on some parameters like visitor's country, website they visited from, UTM parameters. Few of them ask upfront "What are you trying to solve today ? " ,

Once you identify the prospect, then few websites change the headings, sub headings , logos to create a personalization.

I don't think any one will personalize whole page. Instead, sometime they create a dedicated landing page per prospects type like For Buyers , For Sellers etc.

I wouldn't put much thought into this beyond maybe just supporting dark/light themes to match the OS settings. With one big caveat. If you're building a B2B app, then you should think about whether your website would benefit from white-labelling (e.g. custom domains, logos, branding and other assets), being aware that if you're not careful this can add an extra layer of complexity to everything you do.

First, you need to learn how to work with A/B testing, categorize users into segments, and, based on the assumptions, introduce some personalized features or content into your product: creating personalized features directly from A/B segments is a common practice in large companies. For example, allocate feature A to young people and feature B to older generations. Each feature should have its own feature-toggle, and each user can belong to multiple segments at once.

Many services offer feature-toggle and A/B testing capabilities, and deciding which one to choose can be quite challenging. Your decision should start with an evaluation of the project's current architecture.