And to me it is feeling like I am headed to Dumbo. Dumbo and Union Square are two places in town that have tech clusters. There are a whole bunch of tech startups congregated in those two locales.
If there are other such clusters in the city, I am not aware of them as of yet. I am surprised there are not similar clusters in Williamsburg and Chinatown. I know of at least one major tech company that is based out of Chinatown, but I don't think you would call that a cluster.