Twitter's policy guru in the UK Nick Pickles is heading to Silicon Valley to take up a new role as a senior strategist at the social networks headquarters.
The former privacy campaigner joined Twitter in 2014 and has overseen the social network's relationships with government at a time when it has been under scrutiny over issues such as fake news and extremist content.
Pickles last year faced a particularly tough grilling from the Home Affairs Select Committee - in particular from its then chair Yvette Cooper - along with executives from Google and Facebook over efforts to tackle abuse.
Most recently he gave evidence to a committee of MPs in the US investigating fake news. Previously he was director of Big Brother Watch.
Twitter last week reported its first ever quarterly profit signalling a turnaround in its business.