Dozens of factors—from food to mood—can affect skin health, which makes picking products to address dermatological woes a gamble. Atolla co-founders Meghan Maupin, Sid Salvi, and Ranella Hirsch, who met while studying at MIT, realized that data science could help. To create a bespoke serum, customers complete a lifestyle survey and take simple at-home tests to determine their oiliness, pH, and moisture levels. For example, the number of black speckles on a paper strip pressed to your forehead can reveal how slick you get in a given month. Soon, users will be able to scan non-Atolla products to check how well they’ve worked for customers with similar issues.