Claritas One
Consulting/Cloud/SaaS Architecture
Multi-tenant by design

SaaS
architecture.
Designed for scale.

Multi-tenant platforms built for enterprise buyers and product-led growth teams. We design the tenancy model, the data isolation, the platform team topology — and the architecture diagram your largest prospect reads before they sign.

→ 40+ platforms·pool / bridge / silo·API-first·principal-led
Platform telemetry/live

Requests / second · sampled

0
avg p99 < 80ms · tenant-scoped

Tenant distribution

pool · 312 tenantssilo · 4 enterprise
DWG02of 04
Multi-tenant isn't a pattern. It's an economic model.
Enterprise procurement reads your arch diagram before they sign
Noisy-neighbour is the #1 cause of churn for platform SaaS
BYOK is the line between prosumer and enterprise
Platform team topology decides engineering leverage
Row-level security is not data isolation
The hardest SaaS decisions aren't in the code
Multi-tenant isn't a pattern. It's an economic model.
Enterprise procurement reads your arch diagram before they sign
Noisy-neighbour is the #1 cause of churn for platform SaaS
BYOK is the line between prosumer and enterprise
Platform team topology decides engineering leverage
Row-level security is not data isolation
The hardest SaaS decisions aren't in the code

§ 01 — The decision

Tenancy is
a spectrum,
not a checkbox.

The right tenancy model is the one that maps to your ICP, pricing, and compliance envelope — not the one that was trendy when the platform was conceived. Slide the marker to see the trade-offs.

← lowest unit coststrongest isolation →
fig. 02Bridge topology
shared app tier
t1
t2
t3
t4
t5
t6
pool
Starter DB
pool
Growth DB
dedicated
Ent DB

Shared runtime with dedicated resources where it matters.

The pragmatic default for most scaling SaaS. Shared where economics demand it (app, auth, queues). Dedicated where customers demand it (DBs, KMS, egress). Engineering-grade tenancy tiers.

Trade-offs

Unit economics
70
Isolation strength
70
Operational complexity
55
Enterprise fit
75

Typical fit

Mixed ICP (SMB + enterprise)Tier-based pricingSelective BYOK

§ 02 — Inside a request

Tenant context
carried end-to-end.

Every request is resolved, scoped, and routed inside the platform — not inside every service. One middleware, five stages, zero per-call boilerplate.

request lifecycle · tenant-aware
streaming

Stage 01 · Edge

Request lands · WAF · mTLS

tenant-middleware.ts
// stage 01 — edge
await validateToken(req)

§ 03 — Six decisions

The six decisions
that decide SaaS margin.

Get any of these wrong and every roadmap slide gets 20% slower for the life of the product. These are the decisions where we insist on principal-level engagement.

01

Identity & access

Workforce, customer, and machine identities with tenant-aware authorisation. SSO, SCIM, and scoped API trust as defaults.

02

Data isolation

Row-level security, per-tenant KMS, BYOK for regulated tenants, and encryption boundaries that survive a compliance audit.

03

Noisy-neighbour defence

Quota enforcement, circuit breakers, bulkheads, and tenant-aware rate limiting. The largest customer can't starve the smallest.

04

Control plane

Onboarding, provisioning, entitlement, and billing as a first-class subsystem — not an ops tool bolted on later.

05

Observability by tenant

Metrics, logs, and traces carry tenant context end-to-end. SRE answers “is tenant X healthy?” in one query, not five.

06

Platform team topology

A clear split between product and platform — with shared language, accountable on-call, and the funding model that makes it stick.

§ 04 — The drawing

Six layers.
Read it in two minutes.

Adapted per engagement, but the skeleton is stable. The line between product services and platform services is where engineering leverage either compounds or stalls.

DWG / SAAS-REF-02
Platform stack · top-down
06

Customer experience

Web
Mobile
Embed SDK
Edge routing
05

Edge & API

WAF / BotID
API gateway
mTLS
Token validation
04

Product services

Service A
Service B
Service C
Service D
03

Platform services

Identity
Entitlement
Billing
Notifications
02

Data plane

Per-tier DB
Event bus
Warehouse
Per-tenant KMS
01

Foundation

Landing zone
IaC
CI/CD
Observability
Service Platform layer

Scale: 1 row ≈ 1 architectural layer

§ 05 — From the field

Four conversations
we keep having.

Names changed. Details blurred. The shape of the problem — and the shape of the answer — is real.

01 / 04
CTO, Series B, 86 eng

“Our data room just asked how the architecture scales past 10x. We don't have an honest answer.”

— our answer

Tenancy model audit, platform plan, and a hiring profile that fits the capital plan. Six weeks to a data-room-ready answer.

02 / 04
VP Eng, enterprise SaaS

“A $1M ACV prospect needs BYOK, tenant isolation, and SOC 2 — without turning us into a services company.”

— our answer

We design the escape hatches: per-tier KMS, silo-on-demand, and a commercial model your sales team can actually quote.

03 / 04
Chief Product Officer

“One product is becoming three. Every team is rebuilding auth, billing, and observability. We can feel the tax.”

— our answer

Platform layer design. Shared capability gets built once, carries tenant context, and frees product teams to build product.

04 / 04
Group CTO, post-M&A

“We just acquired a SaaS. Their stack is different, their tenancy is different, and both roadmaps can't freeze.”

— our answer

Integration spine: shared identity, entitlement, and data lineage designed so neither team has to stop shipping.

§ 06 — The numbers

// medians across live platforms

01
0+

platforms architected

B-stage to public SaaS

02
0.00%

availability delivered

tenant-scoped SLA

03
<0ms

tenant-level p99

end-to-end, including auth

04
0×

multi-tenant margin lift

median, post-engagement

§ 07 — Open a review

We'll stress-test
your platform in
two weeks.

An architecture review run by the people who've shipped 40+ multi-tenant platforms. You'll leave with a tenancy recommendation, a platform-team plan, and the first three things to change next quarter.

Intake form live
  • Current tenancy model & shape
  • ICP & compliance envelope
  • Platform team context
  • 30-min principal call
Book a review

// scheduled within 48h

Next drawing:

Cloud Security