Blackstone just hired an Amazon Web Services exec who helped the cloud giant do M&A. It's the latest sign that big private-equity firms are muscling in on specialty tech investors' turf.

· Private-equity giant Blackstone just hired an Amazon Web Services exec in an effort to scout out tech deals.
· Christine Feng, a director in corporate development at AWS, joins Blackstone as senior managing director, three months after Blackstone poached another tech-focused dealmaker, Vini Letteri, from KKR. Both staff the...