Building a Multi-Language SaaS Platform: Architecture Guide
Architecture patterns and tools for building multi-language SaaS applications.
Building a SaaS platform that serves multiple languages requires architectural decisions that affect the entire technology stack, from database schema to content delivery strategy. Getting the architecture right from the start prevents costly rework as you expand into new markets.
The fundamental principle is to completely separate translation from code. All user-facing strings should be externalized into locale-specific resource files from day one, even if you initially launch in a single language. For database-stored content (user-generated content, product descriptions, CMS-managed pages), use a language column alongside each content row, storing translations in the same table or a related translations table. The polymorphic translation pattern (a translations table with target_type, target_id, locale, and translated_value columns) offers the most flexibility for content that varies by locale.
Recommended stack: next-intl for Next.js frontend internationalization, Lokalise or Crowdin for translation management with Git integration, DeepL API for automated translation of dynamic user-generated content, and Redis for caching translated responses to minimize API costs. For URL structure, use locale prefixes (domain.com/fr/product) rather than subdomains for SEO benefits, and implement proper hreflang tags. CDN caching with locale-aware invalidation ensures fast delivery of translated content to global users. Edge functions can handle locale negotiation and redirect users to the appropriate language version based on browser settings or geolocation.