Getting a mortgage can be complicated and full of surprises. Ali and Josh Lupo would know: They’ve gone through the process nine times. In 2018, the husband and wife held jobs as social workers and owed a whopping $100,000 in student loans, car loans and credit card debt. After being repeatedly outbid on single-family starter homes, they got creative in order to buy their first house in upstate New York for $158,000 — a multifamily property that came with a tenant upstairs. Since then, the two have bought seven additional rental properties and one forever home, each with another run through the gauntlet that is the home lending process. Their use of this “house hacking” strategy — renting out part of your primary residence to cover future mortgage costs — has given them a unique level of experience and expertise when it comes to getting a mortgage.…