Yafet Z.

I build and repair SaaS web apps with Next.js, React, Node.js, Supabase and MongoDB. I help teams finish MVPs, fix authentication and database issues, and connect APIs so their product is ready for launch. I'm Top Rated with a 100% Job Success Score. My completed Upwork work includes these projects, each with a 5/5 client rating: • A multi-tenant fintech SaaS using React, TypeScript and Supabase • An API layer built in front of Supabase • Pre-launch backend and QA work across Next.js, Supabase, authentication and deployment • Supabase authentication bug fixes What I can help with: • SaaS MVPs, dashboards, client portals and CRM workflows • Next.js/React interfaces and Node.js backends • MongoDB, Supabase and PostgreSQL development • Authentication, access controls and Supabase row-level security • API integrations, webhooks and AI features for web applications • Debugging, pre-launch QA, Netlify deployment and ongoing maintenance My integration work includes a Node.js Meta Conversions API integration for Facebook and Instagram conversion tracking. I also hold API Security Certified Professional (ASCP) and Certified API Security Analyst (CASA) certifications. Share your product goal, existing stack or current blocker, and I'll help define a practical next milestone.