All of this requires experience, not just with the tools of the day, but the problems that need solved are the same that they have been since Mosaid and the NCSA first servers went live.
You may be looking for experience in a particular framework, but those frameworks change. You weren't using Angular five years ago and you won't be five years from now. You need a web developer who can transcend tools that may come and go and adapt to your now and your future.
Web Development is best when your developer undertstands the full-stack. That is they can both build and utilize server-side techologies like creating RESTful API's from your database that can be consumed via your site's web scripting technology and have that output in efficient, well structured elegant front end langages that are cross-browser and mobile friendly.
Knowledge of content management systems (CMS) is also key for many customers because they don't want to think about any of this. They just want to create the content and have it displayed. I've worked for a company that built custom content management systems. I've even built my own and of course I've worked with some of the most popular CMS's like Wordpress and Drupal.
While my comfort zone on the server-side includes PHP, MySQL, and Wordpress, I'm certainly comfortable learning new technologies. I can work with technology like Node.js, Angular and React.
In my career, I've built everything from the website for a major national newspaper to personal portofolio sites for photograpers. I've built dynamic pages for a company that let the HR department use a Google spreadsheet to track employee information and transform that data to an interactive seating chart.