Templates/SaaS Application

SaaS Application

Web ApplicationProductionTeam-scale product

Baseline SaaS architecture with sync APIs, async job processing, webhook billing, and cache layer. Suitable for scalable web apps with background workloads.

Recommended for: SaaS teams shipping subscription products

11 nodes11 connectionsHot-path cachingBackground jobsObservability-ready

Use Case

SaaS products, subscription platforms, dashboards

Best Fit Scenarios

  • B2B SaaS with billing and user roles
  • Product teams splitting sync APIs and async workers
  • Teams that need built-in error visibility from day one

Stack Breakdown

ReactNext.jsNestJSPostgreSQLRedisStripe

Architecture Layers

1Frontend SPA
2API Gateway
3Backend Services
4Data Layer
5External Integrations

Components by Category

frontend

ReactNext.js

backend

API GatewayAuth ServiceNestJS

async

Worker ServiceBullMQ

database

PostgreSQLRedis

external

StripeSentry

Why This Topology Works

Cleanly separates frontend concerns from business logic via an API gateway. Auth, billing, and monitoring are decoupled services, making the stack horizontally scalable and independently deployable.

Scaling Notes

Backend services scale horizontally behind the gateway. Redis caches session data and hot reads. PostgreSQL handles persistent state with read replicas for analytics queries.

Observability

Sentry captures frontend and backend errors. Structured logging flows through the API gateway for traceability.

Typical Bottlenecks

  • API throughput during tenant spikes
  • Background job backlog around billing cycles
  • PostgreSQL write pressure on high-cardinality events

Async Flow and Reliability

User actions stay fast on synchronous APIs while expensive work is queued to background workers. This keeps request latency predictable and avoids blocking checkout, onboarding, or reporting paths.

Upgrade Path

Start with a single API service and worker queue. Then split billing, auth, and reporting into independently deployable services once product usage stabilizes.

Operating Envelope

Complexity is marked as Production with an intended scope of Team-scale product. Use this as a planning baseline before adapting the template to your reliability and team constraints.