Derrick Reimer discusses how to win the 59DaysOfCode competition. He emphasizes that code is less important than design and having a business plan. Good design is critical to the user experience. Contestants will not win without proving their app is commercially viable by submitting a business plan that outlines their marketing strategy, target customers, and competitive advantages. It is important to demonstrate how the app could generate revenue by pitching it as if seeking investor funding. To be successful, entrants need to focus on code, design, and marketing as the "trifecta" and build a team with complementary skills in these areas.