Word Usage – Difference Between “Human” and “People”

As is used to mean because, but it is also used when two events happen at the same time.

In "I must stop now as I have to go out." it means because, but in "She watched him as the train passed close to his house." it doesn't mean because.

As for the sentences you used as examples, both are correct.

BE is notoriously difficult to define, because you can't say what it "is" without in effect using the word itself.

But the difference between BE and BECOME is relatively easy.

• BE designates a state, something which continues unchanged through time.
• BECOME designates an event, a change of state.

Right now you are (BE) not yet a software developer. You are perhaps a student of software development. That is a state. You will continue to BE a student until your state changes. At that point you will BECOME a software developer. After that point you will no longer BE a student, you will BE a developer.

So both ways of describing your ambition are correct. You want to BE a developer; but in order to achieve that state you must BECOME a developer, you must change your present state.