A All APEX developers know that you can develop prototypes really fast. Many times even the whole applications. But sometimes, the expectations from your stakeholders can be very different then what it is possible to do in APEX in reasonable time. Sometimes, the requirements you receive might be weird from your point of view. As a developer, you should think about extending your knowledge to the product world. To think about apps you build from the product/customer perspective. Don't thing too much on the features and technical side, think more about benefits for users and solving users problems. There are some excellent resources on the market and you can get most of them for free. In just few hours of your time you might change your perspective how to develop software. There is a great course and bottomless well of wisdom about building products from Pawel Huryn . Just subscribe to the free (or paid) newsletter, explore the blog or/and go for Continuous Product Discovery M
Mainly APEX, sometimes SQL, PL/SQL, clean code and certifications