Cloud & SaaS Architecture

Serverless is not just FaaS — it is an ecosystem of fully managed services you compose rather than program, billed per use and scaled to zero.

Serverless-first means choosing serverless as the best-fit first option — reached through a sequence of X-first disciplines, not as a dogmatic must.

Compose serverless systems from named patterns — storage-first, functionless integration, gatekeeper bus, choreography vs. orchestration — over an event-driven backbone.

The AWS Well-Architected Framework's six pillars — plus the Serverless Lens — give a shared vocabulary for reviewing trade-offs across security, cost, reliability, and sustainability.

Serverless needs a novel test approach: don't re-couple decoupled services — aim for maximum confidence in minimum time across business logic, integration points, and data contracts.

Operating pay-per-use systems: infer internal state from metrics, logs, and traces, and treat the monthly bill as a direct measure of architectural efficiency.

SaaS is a business model first — a unified, single-version service experience for tenants — and multi-tenancy means collective management, not necessarily shared infrastructure.

Every SaaS environment divides into a control plane that orchestrates all tenants and an application plane where the multi-tenant product features live.

Silo, pool, and bridge express how resources map to tenants — but deployment is not isolation; true isolation needs a separate gatekeeper scoped by tenant context.

Start with onboarding and identity: a fully automated front door that binds every user to a tenant and carries tenant context downstream as a JWT.

Tiers turn multi-tenant levers — deployment, throughput, isolation — into priced value boundaries, while metering and throttling tame the noisy-neighbor problem.