Arry Yu. (Photo via ArryinSeattle.com) Find your “AJ.” Watch out for assholes. And know when to call it quits. closed the book last week on GiftStarter, her 4-year-old Seattle startup that aimed to personalize and simplify the process of purchasing gifts as a group. In an email to GeekWire, Yu said the biggest problem for GiftStarter was product-market fit. The company went through two accelerators, and 500 Startups, but struggled to acquire customers and nail down a robust business model. Yu let go of her employees in April 2016 but kept the company alive, even taking a major personal loan to try and fund it further. But she officially closed up shop last week. In a , Yu thanked her investors — local angels like Heather Redman, Gary Rubens, Rebecca Norlander, and Rudy Gadre — and other supporters. The entrepreneur also admitted that she should have shut down GiftStarter in 2016 and listed 10 lessons from her startup journey. “Startups are really hard,” Yu wrote. “Don’t do them light heartedly or just because it’s the trend. Don’t do it because you’re bored at work. Do it because you cannot exist in life without the big idea going big.” Among her other lessons for founders: “Find the ‘AJ,'” which is someone by your side “that’ll turn left and pounce 5 feet into the air when you just jump left” — a tip she learned from OfferUp founder Nick Huzar. She also advises startups to focus on finding a market before building a product; file proper documentation; and watch out for “assholes posing as advisors just for the vanity of it.” You can read the full post . Yu is now COO at , a Seattle startup formerly known as CakeCodes that lets people earn cryptocurrency by performing micro-tasks.