People all over the world are traveling more for work again. If you’ve flown anytime in the past few months, the packed planes are in part evidence of that. Further evidence that travel is rebounding lies in the number of people staying in hotels, and the money going into startups that serve the industry as well as travelers. Hotel Engine is the latest such startup, having just raised $65 million in a Series B round at a $1.3 billion valuation. Investors include Telescope Partners and Blackstone.