I get this question so often that it's worth posting the answer more publicly. The question goes something like this:
I had 5 interviews for a software development position. 4 went really well - I got all the answers perfectly. I bombed the fifth one though. I don't think I got the best solution, and I made some mistakes in coding. What are my odds of getting an offer?
Let's step back a moment.
First, your interview performance is nearly impossible to judge. So when you say you "bombed" this interview and did "really well" on the others, you don't know that - trust me.
Second, I find it hard to believe that you were basically flawless in all your other interviews. For that to have happened, you either had incredibly easy questions or were one of the best candidates that anyone has ever seen. In my interviews at Google, fewer than 1% of candidates answered my moderate-to-hard difficulty questions "perfectly." Odds are, you made a lot more mistakes than you realize.
Remember that you're judged relative to other candidates (which is why your interview performance is nearly impossible to judge) and on things like:
- how quickly you arrive at a good solution
- how optimal your algorithm(s) are
- how you discuss the trade offs between the different approaches
- how many bugs you make in your code
- how easily you discover those bugs
- how you fix the bugs
All of these factors are qualitative (and relative to how other candidates do them), not binary "correct vs. incorrect" factors. I have never, ever asked someone a question like, "Design an algorithm to ..." and reported that a candidate got the question "correct" or "incorrect."
So when you say you got a question "correct," it doesn't make sense (unless it was a simple factual question). You can say you did an interview flawlessly, but that would mean that you immediately spit out the optimal solution to a problem (and somehow you knew it was optimal), coded it in completion without a single mistake, and checked for bugs anyway but there weren't any. Did you? It's possible, but it's far more likely that you made a bunch of mistakes along the way.
And that's okay - everyone makes mistakes in interviews. And you can get an offer while bombing one interview. But again - you don't know which one you bombed, if any. I've see a lot of candidates say that they did "bombed" in one interview, when in fact, that was their best interview of all.