Couro — AI Biomechanical Analysis Platform

Overview

Couro is an AI-powered biomechanical analysis platform for athletic running performance. Coaches and athletes upload a running clip (treadmill or track) and the system returns:

• A composite Couro Score (0–100)
• Four joint-level scores — shoulder, elbow, hip, knee
• A pose-estimation overlay video
• A stride-isolated video
• AI-generated textual insights on running form

Results are tracked longitudinally per athlete with score-trend charts and session-over-session comparison. Built at Codecubics as a cross-platform monorepo: a React Native mobile app and a Next.js 14 web app, both backed by Supabase + an external AI/Patient API. 30% measurable improvement in athlete performance metrics, 95% production uptime across staging and prod via Terraform-provisioned AWS.

Architecture

A distributed monolith with a BFF pattern — Next.js API routes proxy to an external AI service while owning the auth, billing, and webhook surface.

┌─────────────────────────┐         ┌─────────────────────────────┐
│  React Native           │         │  Next.js (App Router)       │
│  • Auth screens         │         │  • Server + Client comps    │
│  • Athlete management   │         │  • API routes (BFF)         │
│  • Video upload         │         │  • Server actions           │
│  • Score display        │         │  • Auth-guard middleware    │
│  • IAP billing          │         │                             │
└────────────┬────────────┘         └──────────────┬──────────────┘
             │                                     │
             ▼                                     ▼
        ┌────────────────────────────────────────────────┐
        │            BFF / API Layer                     │
        │  Auth proxy → External API + Supabase          │
        │  Patient proxy → api.couro.io                  │
        │  Session proxy → api.couro.io/sessions/*       │
        │  Billing → Stripe SDK                          │
        │  Webhooks → Stripe + Apple S2S                 │
        │  Account → Supabase direct                     │
        └────┬──────────────┬────────────────┬──────────┘
             ▼              ▼                ▼
        ┌─────────┐   ┌──────────┐   ┌──────────────────┐
        │ Supabase│   │ Stripe   │   │ External AI API  │
        │ Auth    │   │ Billing  │   │ Pose estimation  │
        │ Postgres│   │ Subs     │   │ Score generation │
        │ RLS     │   │ Portal   │   │ AI insights      │
        └─────────┘   └──────────┘   └──────────────────┘

Highlights

Cross-platform delivery

A React Native 0.74 app for iOS + Android (couro-mobile-app) and a Next.js 14 web app (couro-web-app) share the same Supabase auth and external AI backend, so a coach can record on iPhone and review on a desktop browser without re-uploading.

Video → AI pipeline

Video uploads are base64-streamed to the BFF, forwarded to the external API for pose estimation and joint-angle scoring, and returned as structured JSON + S3 video URLs. The frontend renders the pose-overlay and stride-isolated clips through react-player (web) and react-native-video (mobile).

Longitudinal tracking

Per-athlete score history is rendered with Recharts + Chart.js on web and react-native-chart-kit on mobile, with bezier interpolation between sessions so coaches can read the trend, not just the spikes. Session detail views use circular progress gauges (react-native-svg-circular-progress) for joint-level scores.

Multi-rail subscriptions

• Web — Stripe Checkout + Customer Portal (@stripe/react-stripe-js, server stripe SDK).
• iOS — Apple In-App Purchases (react-native-iap) with server-to-server receipt verification.
• IAP receipts are validated against Apple's certificate chain using @peculiar/x509 + node-forge for x.509 parsing — no third-party verifier in the loop.
• Token-based consumption model (100 / 1000 tokens-per-month tiers) keeps web and iOS billing reconciled in Supabase.

Multi-provider auth

Email/password + Google + Apple + Facebook OAuth via Supabase Auth, with @supabase/ssr for App Router cookie sessions and a 15-day HTTP-only accessToken on web; AsyncStorage on mobile.

PDF report generation

Printable session summaries via react-to-print + html2canvas-pro keep rendering on the client and the BFF stateless.

Infrastructure-as-code

Terraform-provisioned multi-environment AWS (prod + staging) — ASG-backed EC2 (1–3 instances) behind ALB, with stateless Next.js for horizontal scale.

Tech Stack

Mobile (couro-mobile-app)

Web (couro-web-app)

Backend / BFF