From the rooftop terrace of Kosovo’s innovation center, Shpend Lila pointed out a red-brick building on a recent weekday morning. Originally the headquarters of a local publishing agency, the modernist structure was Pristina’s tallest for decades. Today, it is dwarfed by high-rises housing a growing mix of tech companies — including SPEEEX, a business processing outsource firm on track to become the country’s first unicorn.