MADRID/STOCKHOLM—Web Summit, one of the largest tech conference organizers, will open its doors next week in Lisbon for its first in-person event since the pandemic struck, with the likes of Microsoft, Amazon, and Apple set to speak. Hot on the heels of the Mobile World Congress (MWC) in Barcelona in June, it will be the next large tech conference to test a return to normal, reuniting entrepreneurs, top executives, and major investors after 19 months of video meetings. About 40,000 attendees are slated to join the summit, which will feature 1,000 speakers ranging from Microsoft Vice Chairman Brad Smith to Apple software boss Craig Federighi, addressing audiences including founders of companies which have only recently emerged. “It’s almost 100 percent in-person attendees—we don’t sell online-only tickets,” Web Summit co-founder Paddy Cosgrave said. “Most of these company founders have never been seen in person: they went from nowhere to somewhere exclusively …