Expression seeks a Senior Full Stack Developer to design, build, and maintain web-based applications using modern front-end and back-end technologies. You will work with small, feature-focused teams to engineer solutions and mentor team members, collaborating with data scientists, DevSecOps engineers, and product designers to contribute to an Agile development process. Fully remote, full-time role; US citizenship required for security clearance; DoD Secret clearance is nice to have but optional.