[KineticLensman]

Crucially, don't start the discussion with "do you still want me" but with "I'm concerned that I might run into problems and wanted to discuss how we can avoid them" (or something like that).

Some managers would welcome this discussion. It shows that you are aware that you have limitations and that you would like to improve. If nothing else it helps keep the manager / company from placing you on a task that you wouldn't be able to complete successfully, which would ultimately hit their bottom line. If the company / management are sufficiently enlightened (such companies do exist), they may be able to find additional training or development opportunities to enhance your skills

FWIW, when I was a manager, I ALWAYS liked to find things out before they created a problem, when there was time to fix them, rather than in the middle of some critical task.

Good luck!

[michaelbuckbee]

An even better starting point would be: "Hey Manager, I'm dissatisfied with the quality of my work on medium_complexity_project and want to make sure that I'm improving going forward. Here are the steps I'm taking (list steps) do you have any other suggestions on what I can do to improve here?"

[KineticLensman]

Yes. In fact this is an interesting topic in its own right - how do you approach management when you have found a problem. In my experience, there is a sort of scale here, along the lines of:

* do nothing and keep quiet (almost always the wrong thing)

* say "help"

* say "I've found this specific problem, but I don't know what to do"

* say "I've found this specific problem, here are some options for fixing it - what do you think?"

* say ""I've found this specific problem, doing X will fix it - what do you think?"

This will vary a lot in practice and depending on circumstances, but I think as people increase in experience and knowledge they tend to approach management with solutions rather than just problems.