Remote senior developer position for profitable SaaS company, resOS. Requires at least 5 years of full-stack JavaScript experience, specifically with Node, React, and MongoDB; Meteor and Material-UI experience is a plus. Responsibilities include improving code quality, testing, deployment, and mentoring junior developers. Competitive salary between €5,000 and €7,200, with flexible working hours, remote work options, and social gatherings. Candidates must be based in Europe, within 2 hours of GMT+2. Immediate start preferred, but not urgent. Apply with GitHub link and project examples.