The terms "web developer" and "software engineer" are a bit muddied and it's not really anybody's fault (just years of inadvertent misuse and abuse as non-industry folk such as recruitment agencies have struggled to describe what it is we do).

There are different types of software engineer:

• There are software developers, who create software. You can argue that these developers are indeed engineering software in the same way that you could argue that building your own car makes you a mechanic. In this context, most developers are software engineers (e.g. checking your oil and fluids doesn't make you an engineer).
• There are academic software engineers, who actively pursue software engineering principles. In this context, software developers are not engineers (the distinction is required).

And there are also different types of web developer:

• There are developers who develop software for the web, whether client or server side, as a byproduct of the software they create, using the languages and platforms that are relevant to their product or service.
• There are developers who specifically target the web using languages and platforms that are also specifically targeted for the web.

So for example, let's take Twitter. Twitter has both engineers and web developers. The engineers are busy writing the backend and exposing its APIs, while the web developers are creating its front end (not just client side!).

In contrast, let's take a sole PHP developer working on a bespoke product. He/she is both an engineer and a web developer, creating both the backend software and the front end.

In contrast again, let's take a sole PHP developer creating a website for a client by customising Wordpress (or Shopify, or something off the shelf). Are they an engineer? If they are not actually architecting either the back or front end, then I would be tempted to say not.

So, to cut a long explanation short, these days you have to take the context into account to determine what they are really looking for. Not all engineers are web developers (obviously), but also not all web developers are engineers, and the distinction really lies in the role itself and its requirements.

In your example above, I would say that Google's interpretation of and distinction between "web developer" and "software engineer" are pretty clear cut as they make those distinctions in the projects that they publish and contribute to (Angular, Kubernetes, etc). A "web developer" at Google will almost certainly be working primarily on the client side, or on the client side of the server side, whereas a "software engineer"'s jurisdiction will almost certainly end at the HTTP API.

I hope that helps, though I realise it doesn't clear much up - it's a bit of a problem in the industry really, and has been for a while, but we seem to be muddling through ok-ish...

It often depends on the company. I've been a web developer for nearly 20 years and in the course of my career I've had titles like "Senior Software Engineer" and "Programmer/Analyst."

In my experience, any web developer worth their salt knows about application architecture, algorithms, scalability, distributed systems, version control, databases, data migration, APIs, testing, and on and on.

It's the companies who realize a good web developer is a software engineer that often use that title whether you are building web applications, embedded software, etc. In these cases, Facebook/Google may very well have web developer positions for hire under the "Software Engineer" title.

I have to respectfully disagree with @cdagli. As developers, we all face problems that are already solved. A good developer knows how to evaluate the existing solutions and determine which ones are well done and evaluate when their time is better spent building their own. Or, contributing to open source solutions that meet some of their needs but lack in other areas. If doing unique work was what made someone a software engineer, then there wouldn't be many of them out there.

Also, unlike @cdagli, it's been my experience that a Wordpress developer can be responsible for custom development, integrating with 3rd party systems, and other "software" oriented roles. It's the platform itself that gets a bad name due to many poor implementations and how easy it is to get started but there's a big difference between an editor who builds pages in Wordpress, Drupal, etc. and a developer who implements custom solutions built on these platforms.

If companies were to think like that, then a Java developer who deploys some of his apps on Heroku isn't a software engineer. Slack uses a ton of PHP for server-side application logic in their infrastructure. I bet the developers behind their codebase are considered software engineers. Just my 2 cents but I wouldn't assume every web developer is just building Wordpress pages.

I think a web developer is someone who builds web pages for companies or some media agencies using Wordpress, e-commerce solutions or things like that. Mostly faces with problems that are already solved and implements that solutions taken from others.

On the other hand, a software engineer is someone who designs and implements unique software and thinks about maintenance, code quality, testing, scaling etc. Mostly faces with problems that are not already solved or needs optimization.

Companies like Google and Facebook needs software developers more than web developers since they are pioneers in most web technologies and mostly their engineers will be the ones that faces with unsolved problems.