In my last job- which lasted for 2 years (it was also my first job)- I was given "needs improvement" rating. After that, I changed my job.
In my current job (it has been 1 year), my first 6 months have been fairly productive, though I have been alluded to pace up. Last few months have been rather slower productivity wise.
I find it hard to concentrate (though I am technically capable of completing the given task, or to reach the answers/solutions when I don't know them at first) and miss my deadlines. I don't feel much motivated to work (though, I always intend to perform better and be a better developer).
As much I would like to blame my depression for it, I know that isn't the cause. I also feel inferior because of missing my deadlines and lagging behind.
Has this happened to you? Is there a way out- did you become from "bad hire" to "valuable asset" to the company?
I've hit several plateaus in my history -- mostly around the time I feel comfortable with something. Thats my sign that I need to learn something new.
You're going to be called a lot of things when you start out, Its all about how you take it. To this day, After ~7 tech jobs, countless "needs improvement", 2 companies founded, and about 1.4M in VC funding --- I still feel like a damn rookie.