I met this person when I was working for my first company. He was not good at work, wrote crappy code, didn't follow rules and standard. He didn't like me for the fact that I always asked him to do a better job.
Five years later, he joined my current company. It implies that he must have been improve quite a bit because the recruiting process is quite tough.
So, the question is should I talk to him? and How to start the conversation?
Shake his hand and say "Nice to meet you again. How have you been doing?" for the following reasons.
It is good to be nice to people and treat them how you would like to be treated.
Say hi when you pass him in the hall. Talk to him at meetings, regarding the topic of the meeting, when you have information to exchange. Other than that, try to act as if this is a person you have never met before. As you noted, it's been five years. In coding terms, that's time for a person to have not improved one iota...or quite a bit, especially if they've gotten through an interview process that you know is pretty thorough and good at weeding out those who can't hack it.
If he brings up your shared past history, say to him what you just said up in your question: it's been five years, you know that your company's recruiting process is fairly tough, and so based on that, you're guessing that he has probably improved and expanded his skillset quite a lot from the last time you two worked together.
That has the advantages of:
But, may I ask: why do you say he's 'your enemy'? Is this person truly 'your enemy', someone you would never again work with under any circumstances; or is this someone who you previously had a negative experience with, but based on your own knowledge of your company's recruitment policies and the fact that it's been half a decade since you interacted professionally with this person, you're willing to say that what was true then may not be true today?
Me being me, I wouldn't say 'Hi' to him until I see for myself that he is for real. Yeah, five years ago, he stank as substandard. What's to say that he was not great but just good enough to barely make it through the hiring process? The company's recruiting process is tough, but what if it were effective enough to filter out idiots but not idiot savants?
I'd reserve all judgment about him having improved until I see the evidence that he has improved. It's not gracious of me to give him the benefit of the doubt but waiting until I see evidence in his favor accumulate is perfectly righteous behavior, if not exactly gracious, to me.
If I am wrong, I'll be glad to say I'm wrong and I am enough of a big boy to say publicly that I am wrong. In the meantime, I want him to prove me wrong. If he has really improved over the last five years, it shouldn't be too hard for him to prove me wrong :)
No, I wouldn't think of him as my enemy - that's taking it way too personally. The fact is, I got burned by him before. I want to make sure that I am not being burned again. That's a far cry from thinking of this individual as my enemy.
