FORTUNE — There are some big changes afoot at Atlas Venture, which has transformed itself into one of the most influential VC firms in Boston (not only in terms of deals, but also in terms of encouraging growth of the local tech ecosystem). Atlas is expected to add Jon Karlen as a new tech-focused partner, while existing partner Fred Destin is planning to depart. Both moves will take effect sometime next month.
Karlen most recently spent eight years as a partner with Flybridge Capital Partners, where he led such deals as Digital Lumens, Restorando, 33Accross and Open English. He plans to focus on software and e-commerce investing at Atlas, but not on some of the Latin American stuff he did while with Flybridge.
Destin has been with Atlas for more than a decade, having first joined when the firm still had a large European presence with offices in London, Paris and Munich. When the firm basically reinvented and refocused itself in 2010 around Boston, Destin chose to come stateside. Now, however, he tells me that it’s time to return home.
“It’s gut-wrenching and heart-breaking to leave this firm and my portfolio companies,” Destin says. “But I’ve heard about how most ex-pats hit some sort of wall after five years and return to Europe, and my family and I made it almost that long. I’ll keep at least one portfolio company board seat because it’s in the UK, and plan to stay in venture. We talked about the idea of me working from London, but there was a good reason for why we became a one-office firm, so it just didn’t seem like it would work.”
This switch leaves Atlas with four tech-focused partners, but the firm is in talks to add a fifth. It also has three partners focused on the life sciences space. Atlas is investing out of a $295 million ninth fund raised last year
Sign up for Dan’s daily email newsletter on deals and deal-makers: GetTermSheet.com
.