We have developed and implemented a "rigor-first" approach to CS1 instruction, in which we introduce rigorous techniques for understanding algorithms alongside associated programming skills. This core material is developed through a number of engaging problems from more advanced courses in computer science and other natural sciences. These principles are continued in CS2, and the two courses form our "3-2-1" first-year sequence: three programming paradigms and two models of program execution are explored on a single platform. This article discusses the design of our CS1 course, its role in the computer science curriculum, and our experiences with it. Preliminary assessment suggests this approach has merit in our curriculum.