I build AI-powered SaaS
end to end.
Full-stack developer from Manila. I specialize in Next.js + LangGraph + Supabase — from the agent state machine and RAG pipeline down to the Postgres schema and the operator UI. Currently running Aya, a multi-tenant AI receptionist with real paying clients.
Things I've built
Aya
LiveMulti-tenant AI receptionist platform — live at 4 dental clinics in the Philippines, producing 50+ qualified leads. Niche-agnostic agent core, deterministic LangGraph loop, RAG with operator-visible citations, HMAC-signed booking.
LangGraph RAG Starter
Public repoMinimal LangGraph.js RAG agent — retrieve → grade → generate | refuse. Zero embeddings required, runs in 30 seconds with no API key. A clean starter for agentic RAG patterns.
simple-pos
In progressOffline-first point-of-sale designed for small and medium retail stores. Works without internet — local writes hit IndexedDB immediately; a background sync manager pushes changes when connectivity returns.
Client engagements — anonymized
LiveProduction work delivered through CliqueHA Information Services OPC. Client names are under NDA, so this section lists the problem shape and the interesting technical work.
Who I am
I'm Belteshazzar Marquez — a full-stack developer based in Manila. I studied Computer Engineering (embedded systems, IoT, real-time applications) at the University of Mindanao, and for the past few years I've been building production software for small and medium businesses.
My current focus is AI-powered SaaS — specifically the Next.js + LangGraph + Supabase stack. I like the full path: modeling agent loops as state machines, RAG pipelines operators can actually audit, multi-tenant RLS, and the operator UIs that make the whole thing usable by non-technical owners.
I work at CliqueHA Information Services — a startup where I'm part of the dev team delivering client engagements (NDA — operations ERP, retail inventory, e-commerce). Aya is my own side project, independent of CliqueHA.
Looking for mid-level remote full-stack or AI/automations engineer roles, or serious freelance engagements on AI SaaS. If that's you — let's talk.