arch-atlas

SaaS Architecture Atlas

12 pillars for shipping a mobile + web SaaS in 2026 — concrete stack picks, decisions and edge cases per pillar.

SaaS Atlas
12 pillars
1
IdentityAuth, sessions, orgs, roles, SSO, SCIM — the front door of a SaaS.
2
Multi-TenancyKeep tenant data separated by default, isolated for enterprise — the single biggest correctness lever.
3
BillingSubscriptions, invoices, plans, proration, dunning, tax — the revenue surface.
4
Data LayerSchema, queries, migrations, indexes, backups — the database that everything else trusts.
5
APIInternal tRPC, public REST, signed webhooks, versioning, rate limits, SDKs.
6
Web FrontendApp Router, Server Actions, Shadcn UI, optimistic updates, error boundaries.
7
Mobile FrontendClean-arch Flutter app that's offline-first, syncs to your SaaS backend, and ships push notifications.
8
NotificationsEmail, push, in-app, SMS — fanning one event into the channels each user prefers.
9
InfrastructureMonorepo, deploys, edge, jobs, secrets, preview environments — the boring foundation that scales.
10
ObservabilityErrors, traces, metrics, logs, alerts — the loop that turns 'something broke' into 'fixed in 12 min'.
11
GrowthActivation, retention, referral, expansion — AARRR funnel as code.
12
ComplianceSOC 2, GDPR, audit logs, encryption, data residency — the controls that unlock enterprise revenue.