Jonattan Steven Pescador Fonseca

I am Steven, an independent SaaS Architect and Full-Stack Tech Lead. I don't just write disposable code; I engineer scalable Minimum Viable Products (MVPs) designed to automate processes, reduce operational costs, and drive revenue from day one
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💻 My Core Stack: • Frontend: React 18, Vite 5, TypeScript, Tailwind CSS, TanStack Query
. • Backend & BaaS: Supabase (PostgreSQL), Edge Functions (Serverless), advanced Row Level Security (RLS)
. • Focus: PWA transformation (Offline-first) and Technical React SEO (Prerendering)
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🏆 Proven Track Record (Case Study: SportPago): I recently architected a complete B2B/B2C SaaS platform from scratch to production
. Highlights include: • Multi-tenant Security: 16 relational tables with strict RLS for 100% data isolation
. • Business Automation: Engineered an automated 'Payment Semaphore' via Cron Jobs and Edge Functions to update billing statuses in real-time
. • Retention Workflows: Utilized pg_net and the Resend API to trigger transactional emails directly from the database, eliminating expensive third-party tools
. • Global Reach: Dynamically internationalized (i18n) into 4 languages with dynamic currency handling
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🚀 What I Offer to Founders & Agencies:
Custom SaaS MVP Development (Fixed-price builds ready to scale).
Strategic architecture consulting and refactoring.
Let’s build an architecture that scales. Send me a DM to discuss your core business problem.