Senior Full Stack Engineer

Overview As a Senior Full Stack Engineer at Sincere, you own end-to-end product improvements across a broad stack, influencing customer value and UX. You collaborate with product, design, and DevOps to identify pain points, shape solutions, and ship high-quality features. You’ll leverage AI-assisted development tools and monitor product impact to drive pragmatic tradeoffs and reliable experiences. This role offers ownership, cross-functional impact, and opportunities to shape large-scale customer-facing applications. Compensation / Benefits100% Health, Dental & Vision coverage401K Plan with Profit ShareAnnual bonus potentialHealth & Wellness stipendsPaid time off plus 12 paid holidays & Summer FridaysPaid parental leave ResponsibilitiesBuild full-stack features across Ruby on Rails and Next.jsOwn product initiatives end-to-end from ideation to launch and iterationPartner with product managers and designers to identify pain points and opportunitiesLeverage AI-assisted tools (Claude Code, Codex) to explore, develop, test, and shipMake practical technical decisions balancing speed, quality, and maintainabilityDeliver polished, user-focused experiences with strong UXUse Datadog and Mixpanel to monitor production behavior and inform decisionsChampion new ideas and continuously improve products and engineering practices Key requirements7+ years of professional software developmentProficiency across Ruby on Rails, TypeScript, React, Next.js, MySQL/Postgres, Redis, MongoDB, Sidekiq, OpenSearch, AWS, DockerFluent with AI-assisted development tools (Claude Code, Codex)Experience building and maintaining large-scale customer-facing web appsProduct-minded with strong instincts for customer needs and business valueSelf-starter who brings structure to undefined problems and executesCollaborative with DevOps, understanding of cloud infrastructure (AWS), TerraformPragmatic improvement of existing architectures and codebasesCollaborative and low-egoStrong communication and craft prideDetail-oriented with a focus on customer experienceRuby on RailsTypeScriptReact