The SaaS architecture decisions that matter most at early stage

When building an early-stage SaaS product, speed is your primary metric. However, bad early choices can slow you down to a crawl. Here are the four pillars of early-stage SaaS architecture that you must get right on day one. ## 1. Multi-Tenant Database Strategy Should you use database-per-tenant, schema-per-tenant, or tenant-id columns with RLS? For 95% of early SaaS, **tenant-id with Row Level Security (RLS)** is the right path. It is cheap to run, simple to query, and scales well enough for your first 10,000 customers. ## 2. Billing Integration Do not write custom subscription logic. Use Stripe Billing or Paddle. Decouple your system auth status from Stripe events by relying on webhooks to keep sync.