01
Multi-tenancy
Organisations, members and per-tenant data isolation enforced at the database with row-level security.
- Org model
- RLS
- Data isolation
Build a SaaS that survives success
Ship a SaaS that can take money and scale from day one.
SaaS development at Oxwyn Studio means building a paying software-as-a-service MVP on Next.js and Postgres with multi-tenancy, Stripe subscription and seat-based billing, role-based access control, feature gating and product analytics designed in from the first commit, so the product can safely take money and scale past its first hundred customers without a rewrite.
SaaS control plane
Monthly recurring revenue
$48,200
Active orgs
1,284
Seats in use
6,910
Plan distribution
Starter
46%
Pro
34%
Scale
20%
Activity stream
New signup
NorthwindUpgraded to Scale
Acme CoSeat added
GlobexR&D pipeline
From prototype to a SaaS that scales
Each foundation is designed in deliberately, in order, so the product can take money on day one and grow without a rewrite later.
- Tenancy
- Billing
- Roles
- Analytics
- Admin
- Scale
Why you need this
The three things that sink most SaaS builds.
Pain 1
Charging money turned into a full refactor
Plans, seats, trials, proration, invoicing and access rules all have to land at once, on top of code never designed for them, while real customers are already using the app.
Pain 2
Tenant data leaked between accounts
One customer seeing another's data is the single worst SaaS failure. It ends trust, contracts and often the company. Bolted-on tenancy almost always has a gap.
Pain 3
No idea what users actually do
Pricing, onboarding and retention run on hunches. You cannot see activation, where trials stall, or which features drive upgrades, so growth decisions are guesses.
Where it starts
Every SaaS starts as a drawing. We make sure it survives contact with real customers.
MRR & billing simulator
Model the revenue your billing must handle
Subscriptions, seats and metered usage compound fast. This is the exact billing model we wire in with Stripe, so the numbers below are revenue the app can actually charge and collect.
120
5
£24
£8
Monthly recurring revenue
£15,360
£184,320 annual recurring revenue
Seats £14,400Metered £960
Hand-coded billing handles all of this, seats, proration, trials and metered usage, without breaking when a customer upgrades mid-cycle. That is the part prototypes skip.
Illustrative model. Real MRR depends on churn, discounts and plan mix, all of which the billing system we build tracks for you.
The method
Five foundations, built in the right order.
A repeatable build path: model multi-tenancy first, wire Stripe billing, add roles and gating, instrument the funnel, then launch the paying MVP with a runbook your team can operate.
01
Model tenancy
Pick the isolation model, design the org and membership schema, and enforce it with row-level security before any feature is built.
Org modelRLS
02
Wire billing
Connect Stripe for subscriptions, seats and metered usage, with idempotent webhooks that keep entitlements in sync.
StripeSeatsMetered
03
Roles & gating
Build role-based access, team invites and feature gating so plans, permissions and limits are enforced everywhere.
RBACInvitesFlags
04
Instrument
Capture activation, retention and feature-usage events, and build the admin console to support and understand customers.
AnalyticsFunnelsAdmin
05
Launch & iterate
Ship the paying MVP, watch real usage, and harden the parts that take live load, with a runbook your team can operate.
LaunchRunbook
Multi-tenant isolation
One database. Every tenant sealed off.
Org A
Org B
Org C
RLS gateway
stamps org_id
stamps org_id
Every query scoped at the database, not just in app code
One database, isolated rows
Org A rowssealed
Org B rowssealed
Org C rowssealed
What's included
Every SaaS build ships with this.
- Multi-tenant data model with row-level security
- Stripe subscriptions: seats, metered usage, trials and proration
- Role-based access, team invites and feature gating
- Product analytics: activation, retention and feature usage
- Admin console with safe impersonation and audit logging
- Transactional email for invites, receipts and lifecycle
- Onboarding flow and customer billing portal
- Operations runbook and handover so your team can run it
What you receive
A product you own, not a template you outgrow.
SaaS control plane
The owner dashboard: MRR, active organisations, plan distribution and live signups at a glance.
Billing and plans
Stripe-native plan tiers, seat management, metered usage and invoices with a self-serve portal.
Teams and roles
Organisation members, role badges, invites and a permission matrix with feature flags.
Product analytics
Activation funnels, retention cohorts and feature-usage insight so growth runs on data.
Ship day
Day one in production, with billing, roles and observability already wired.
What we build
Six SaaS foundations. One stack you fully own.
From multi-tenancy and Stripe billing to roles, feature gating, product analytics and an admin console, every part is built into a codebase you own, with no platform lock-in.
Takes money from day one
02
Subscriptions and billing
Stripe-native plans, seat-based and metered pricing, trials, proration, invoices and a billing portal.
- Stripe
- Seats
- Metered
- Proration
03
Roles and teams
Role-based access control, team invites, ownership transfer and granular permissions across every surface.
- RBAC
- Invites
- Permissions
04
Feature flags and gating
Plan-based feature gating and flags so you can ship, limit and price features without redeploying.
- Flags
- Plan gating
- Limits
05
Product analytics
Activation funnels, retention cohorts and feature-usage events so pricing and onboarding run on data.
- Funnels
- Cohorts
- Events
06
Admin and support
An internal admin console with safe impersonation, audit logging and the controls to support customers.
- Admin
- Impersonation
- Audit log
No lock-in. The stack we build your SaaS on, all of it yours to own and extend.
- Next.js
- React Server Components
- PostgreSQL + RLS
- Stripe Billing
- TypeScript
- Product analytics
FAQ
Questions founders ask before they build.
What exactly is a SaaS MVP build?
It is a paying product with the foundations that decide whether it scales: multi-tenancy, subscription billing, roles and product analytics, built on Next.js and a Postgres database. It is the smallest version that can safely take money and grow without a rewrite.
Why not just add billing and tenancy later?
Because both touch every table and every route. Retrofitting multi-tenancy or billing onto a prototype usually means a large, risky refactor under live customer load. Designing them in from commit one is dramatically cheaper and safer.
How do you stop one customer seeing another's data?
Every table is scoped by organisation and protected with row-level security, and requests pass through a gateway that stamps the org context. Isolation is enforced at the database, not just in application code, so a single bug cannot leak data across tenants.
What billing models can you support?
Stripe-native flat-rate plans, per-seat pricing, metered and usage-based billing, free trials, proration on upgrades and downgrades, invoices and a self-serve customer billing portal. The MRR simulator on this page reflects the model we wire in.
Do we own the code and the data?
Yes. You own the repository, the database and every integration. There is no platform lock-in and no per-seat tax to a third-party app builder, you can host it and evolve it however you like.
What stack do you build SaaS on?
Next.js with the App Router and React Server Components, a Postgres database with row-level security, Stripe for billing, and product analytics. The same modern, owned stack we use across every service.
Can you take over an existing prototype?
Often, yes. We audit the prototype, map what is safe to keep, and add the tenancy, billing and analytics foundations around it, rather than throwing away working product.
How do you handle product analytics and privacy?
We instrument activation, retention and feature-usage events with a privacy-conscious setup, scoped per tenant, so you get the funnel insight you need without mishandling customer data.
Ready to build your SaaS?
Foundations first. Scale without the rewrite.
Bring the napkin sketch. A senior engineer maps it to tenancy, billing and a launch window, on a 15-minute call.
