After his little brother died of Oxycontin abuse, Jeremiah Lindemann tried volunteering in a rehab center for people addicted to opioids. He felt awkward, unhelpful and sad, so he stopped. Years would pass before Lindemann, a mapping software engineer from Thornton, found a way to honor his brother and, at the same time, help other families grieving loved ones who overdosed on opioids. Lindemann, skilled at digging up and then mapping data for cities, counties and state governments across the country, took his day-job talents to stoke an after-hours project.