Is any company safe? Twitter lays off 336 software engineers

Almost all of the cuts from the 4,100 strong workforce are coming from its "product and engineering" division, rather than in marketing or sales. Almost at the same time as cutting staff, Twitter rolled out its "Moments" service that aims to collect tweets and links about noteworthy news events, and is considering tweets where links and names aren't included in its 140-character limit.

But culling engineering jobs is a shocking act in a field where poaching is commonplace, such is the intense competition for staff. Ego-pumped rivals try hard to dismiss any loss they suffer to a competitor. Or in the case of Elon Musk, founder of the electric vehicle maker Tesla, a rival such as Apple is downgraded to jumped-up rival. "They have hired people we've fired," Musk said recently about Apple having poached a number ofkey members of his staff. "We always jokingly call Apple the 'Tesla graveyard'. If you don't make it at Tesla, you go work at Apple.