There are likely more skills that you have beyond language which you have developed in Avionics SW. There are high verification/validation SW work environments

There are likely more skills that you have beyond language which you have developed in Avionics SW. There are high verification/validation SW work environments which you probably have developed skills (e.g. medical or automotive). There are likely 'complex systems' or architecture areas of software where you might have developed transferable skills - esp. if you've done things such as Avionics integration. (perhaps cloud/big data/web backend) Then there is general embedded work (pickup C/C++). I'd definitively look into some side projects or select some open source projects to contribute to just to demonstrate that picking up new environments isn't difficult. The certificate does that too - but personally side-projects/open source speak to me a little more. It's largely a matter of what you're interested in, but I'd lose the thought that because the language & dev environment is new, you'd come in at an entry level. With 9 years of experience in SW, you're a mid to senior dev and you should take confidence in the value of that experience.