[Remote] Senior Software Engineer - Finance & Business Systems

Note: The job is a remote job and is open to candidates in USA. Midwestern is a profitable, fast-growing SaaS platform in the mission-driven technology space. They are seeking a Senior Software Engineer to build systems at the intersection of Finance, Engineering, and Operations, focusing on making unit economics visible and actionable.ResponsibilitiesOwn full-stack delivery from UI to backend services, including database tuning and performanceBuild new features start to finish - architecture design, coding, automated testing, and production supportWork closely with teammates in a fast-paced, agile environment across pods and the broader Engineering orgTackle technical issues throughout the stack and contribute to shared documentationContribute to coding standards, tech debt refinement, and system security monitoringParticipate in interviewing and onboarding new team membersParticipate in on-call support rotation (team-based, paired)SkillsStrong experience with Ruby on RailsSystem design experience focused on incremental, scalable, resilient architectureComfortable across the stack - backend services, databases, and light frontendExperience with modern frontend frameworks (React, Vue.js)SQL database experience (PostgreSQL, MySQL, SQLite)Deployment experience on Heroku, AWS, or similar5+ years of hands-on development experienceComfort with financial concepts: margins, COGS, pricing, revenue recognition, or unit economicsExperience building systems where correctness, auditability, and explainability matterAbility to work with non-technical stakeholders and translate ambiguous business questions into concrete technical workComfortable with ambiguity - shaping the problem, not just executing against a specDeep Ruby on Rails and RSpec expertisePostgres database administration experienceShipped code supporting tens of thousands of users including enterprise customersOperations/SRE experience including networking, caching, database, and performance triageExperience in fundraising, crowdfunding, fintech, or payments productsStartup environment experienceExperience building internal tools for Finance or Operations teamsCompany OverviewMidwestern Interactive | Great vision needs great people to bring it to life. It was founded in 2012, and is headquartered in Joplin, Missouri, USA, with a workforce of 51-200 employees. Its website is https://midwestern.com/.