Senior Full-Stack Developer (React + Node.js) | Enterprise SaaS MVP

We are developing an enterprise web platform that digitizes complex business onboarding and workflow processes. We are looking for an experienced Full-Stack Developer to lead the technical implementation of our MVP. This is a greenfield project where you'll work directly with the founder to build a scalable, secure foundation that can evolve into a long-term enterprise platform. The initial engagement is expected to last approximately 3-5 weeks and will focus on delivering the first functional MVP. Responsibilities You will be responsible for designing and implementing the technical foundation of the platform, including: Backend architecture REST APIs Database design Authentication and authorization Frontend implementation Documentation Development best practices Technical recommendations and architecture decisions The application includes secure user onboarding, document management, workflow automation, approval processes, and mock integrations with external enterprise systems. Detailed functional requirements will be shared with shortlisted candidates. Required Skills 5+ years of professional Full-Stack development experience React TypeScript Node.js NestJS (preferred) PostgreSQL REST API design JWT Authentication GitHub Docker Experience building SaaS or enterprise business applications is highly preferred. Experience with workflow systems, onboarding platforms, document management, or regulated industries is a significant advantage. What We're Looking For We're looking for someone who enjoys solving technical problems—not just writing code. The ideal candidate should be able to: Design scalable software architecture Think through future extensibility Write clean and maintainable code Communicate technical ideas clearly Recommend improvements when appropriate Take ownership of deliverables Project Structure Remote engagement Approximately 3-5 weeks Milestone-based delivery Weekly progress reviews Source code hosted in our GitHub organization NDA required before sharing detailed specifications Successful completion of this phase may lead to additional development work as the platform evolves. Please Include in Your Proposal A short introduction. Your most relevant SaaS or enterprise project. Your role in that project. The architecture or technical decision you're most proud of. Your GitHub profile or portfolio (if available). Your availability over the next six weeks. Please avoid sending generic AI-generated proposals. We're interested in understanding how you think and solve technical challenges.