Core system
Node.js (NestJS)
Runs the core system layer for business logic, APIs, bookings, operations, billing flows, and connected product modules.
Tech stacks
Technology powering the Fitbiz OS stack.
The platform combines a scalable backend, a dedicated AI layer, cross-platform apps, flexible hosting, modern LLM infrastructure, and delivery-ready notification systems built for serious fitness operators.
SYSTEM STACK
core_system: Node.js (NestJS)
ai_layer: FastAPI (Python)
mobile_app: React Native
web_framework: Next.js (React)
hosting: AWS / GCP / Azure
llm_layer: OpenAI / Gemini / Claude
notifications: Meta WhatsApp Cloud API / FCM
Architecture
Core systems for a modern fitness platform.
Each layer is selected to support performance, extensibility, AI readiness, mobile delivery, and reliable operator workflows across the entire Fitbiz OS product.
AI layer
FastAPI (Python)
Powers the AI layer for nutrition intelligence, decision support, scoring systems, automation logic, and future model-driven services.
Mobile app
App - React Native
Supports branded mobile experiences for clients and coaches across iOS and Android without maintaining two separate native codebases.
Web framework
Framework: Next.js (React)
Delivers fast web application surfaces for admins, operators, and business owners with a modern React-based framework foundation.
Hosting
Hosting: AWS / GCP / Azure
Designed to deploy on major cloud environments so infrastructure can align with scale, region, compliance, and enterprise requirements.
LLM layer
OpenAI, Gemini & Claude
Supports a flexible LLM layer for AI workflows, reasoning tasks, content generation, copilots, and future intelligent product experiences.
Notifications
Meta WhatsApp Cloud API, FCM
Enables WhatsApp and push notification delivery for reminders, alerts, follow-ups, promotions, and operational communication at scale.