There's more to know beyond the software aspect. Web apps require a lot of knowledge too, but it mostly falls under the umbrella of software. Application softwa

There's more to know beyond the software aspect. Web apps require a lot of knowledge too, but it mostly falls under the umbrella of software. Application software is just one of many things an embedded engineer does. Start with the basic skills you'd need for any software like data structures and algorithms. But you'll actually need to know it for the job, not just for the interview. Add extra low-level computer systems skills. Add electronics skills. Depending on the application, you might also need to know control systems, signal processing, communications theory, hardware security, or computer architecture, for example. Then add the engineering math/physics knowledge for the specific domain. It adds up. If you can't do those things, all of those problems need to already be solved, simplified, and polished for you. At that point, you've avoided firmware engineering and gone right back to application development.