&gt;<i>I like types, but jeez, the vast majority of web systems over the last decade were written in dynamic languages</i><p>That&#x27;s because the vast majority of web systems are glorified CRUD apps, the easiest kind of application one can make.<p>When it comes to the real hard backend parts (not just some queue handling of video conversion tasks for example, but things like search engines, social graph stores, programs for finding the cheapest air tickets, etc.), they&#x27;re usually done in languages like Java, Scala, C++, Go, etc.<p>Heck, even as web front-ends got more evolved, people developed several typing systems to assist us (Flow, Typescript, etc) to solve that need, we got Go, Hack. Optional types are also landing in PHP and even in Python -- there&#x27;s a consensus among many people about a need for such things. And Google wrote their more complex apps in a Java lib that could spat out Javascript IIRC (GWT).<p>As for the non CRUD apps, from PostgeSQL, Chrome, Office and Photoshop to Pixelmator, OmniPlan, Notepad++ and Scrivener, nobody writes those in dynamic languages (where nobody obviously means: some outliers being excepted). One might argue that those are few (they are not, they are merely &quot;fewer&quot; than web systems. Still millions of programmers work in that space), but the point remains: for developing harder apps, people opt to static languages.