Tucked on the second floor of a turquoise building with peeling paint is a five-person tech startup that shares an office with Linn Construction, a property developer. Thar Htet, a cherubic 29-year-old Yangon native who dreams of Google-style success, does double duty as the founder of the app company, Zwenex, and a manager of the construction firm — a family business that’s currently helping to keep his tech venture afloat.