Multi-Region Deployment

Architecture guide for deploying the LMS platform across multiple regions with low latency and high availability.

Architecture Overview

The platform uses a multi-tier deployment strategy: Vercel Edge Functions handle API logic at the nearest PoP, Edge Config provides instant feature flag reads, static assets are served via CDN, and database read replicas reduce query latency for geographically distributed users.

Edge Functions for Low-Latency API Responses

Edge Runtime

Server Actions and API routes run on Vercel Edge Functions, executing at the PoP closest to the user.
Edge middleware handles authentication token validation, locale detection, and tenant routing with sub-millisecond cold starts.
Use the `runtime = 'edge'` export in API routes for globally distributed execution across 30+ regions.
Streaming responses via React Server Components enable progressive rendering regardless of user location.

Vercel Edge Config for Feature Flags

Edge Config

Edge Config provides ultra-low latency reads (~1ms) for feature flags, A/B test assignments, and tenant-level configuration.
Feature flags are evaluated at the edge before rendering, enabling instant rollouts and gradual releases without redeployment.
Tenant-specific module toggles (gamification, food safety, CRM) are stored in Edge Config for instant activation.
Maintenance mode and rate-limiting rules propagate globally within seconds of an update.

CDN for Static Assets

CDN

Static assets (JS bundles, CSS, images, fonts) are served from Vercel's global CDN with automatic cache invalidation on deploy.
Course cover images and uploaded files are stored in Vercel Blob Storage with edge-cached delivery.
ISR (Incremental Static Regeneration) pre-renders marketing pages and course catalogs at the edge with configurable revalidation intervals.
Stale-while-revalidate strategy ensures users always get a fast response while fresh content is generated in the background.

Regional Database Read Replicas

Database

Supabase PostgreSQL primary database in EU (Frankfurt) handles all write operations with full ACID guarantees.
Read replicas in US-East, US-West, and Asia-Pacific serve read-heavy queries (course catalog, leaderboards, analytics) with minimal latency.
Connection pooling via Supavisor routes read queries to the nearest replica automatically based on the Vercel region header.
RLS policies are enforced identically across all replicas, maintaining tenant isolation globally.

Best Practices

Use Edge for reads, Serverless for writes

Route read-heavy operations through Edge Functions and write operations through Serverless Functions connected to the primary database.

Cache aggressively at the edge

Use ISR with short revalidation windows for course catalogs and long TTLs for marketing pages.

Monitor replica lag

Track replication lag metrics and fall back to the primary for time-sensitive reads if lag exceeds thresholds.

Geo-route with middleware

Use Vercel's x-vercel-ip-country header in middleware to select the optimal database replica and locale.