Cost to Build a SaaS Platform in 2026

What is the cost to build a SaaS platform, and what moves it?

The cost to build a SaaS platform depends on scope far more than on team rate. Four variables dominate: tenancy model, the identity and billing layer, integrations, and compliance obligations. Change any one and the total moves materially.

We do not publish a rate card, because any figure we wrote would be invented before scope is known. Public ranges run from a narrow MVP at the low end to a multi-team enterprise build at the high end. They are not comparable with each other, because the products behind them are not the same product.

Viithiisys has been building software since 2007. This guide explains what drives the number so you can brief a vendor, or your own team, with fewer surprises. If you are still deciding whether to commission bespoke work at all, our custom software development service sets out how we approach it.

Which scope decisions change the cost most?

Rank your scope by how hard each item is to reverse later. Tenancy and data model are expensive to change after launch. A settings page is not.

The usual cost movers are:

• the number of user roles
• the number of third-party integrations (each one means credentials, retries, rate limits and a support burden)
• reporting depth
• any compliance requirement, such as SOC 2 or data residency in a specific country

A B2B product also carries a hidden multiplier: customers will ask for SSO, audit logs and custom contracts as soon as they are larger than you. Decide which of those are in the first release and which are explicitly deferred.

Why does multi-tenancy set your floor?

Multi-tenancy is the choice of how customers share infrastructure. It sets the cost floor because it shapes your database, deployment pipeline, security review and support model, and it is the hardest decision to reverse.

AWS's SaaS Lens in the Well-Architected Framework describes three models: silo (separate stack per tenant), pool (shared resources with logical separation), and bridge (a mix). You can read the definitions in the AWS Well-Architected SaaS Lens.

Silo is quicker to reason about and easier to sell to cautious enterprise buyers. Pool is cheaper per tenant at scale but needs more engineering up front.

How does pooled isolation work in practice?

In a pooled design every table carries a tenant identifier, and every query must filter on it. The failure mode is a single missed filter that shows one customer another customer's data.

PostgreSQL's row-level security lets the database enforce that filter itself rather than trusting each query. That moves the guarantee from developer discipline to the data layer.

It still needs tests. Budget time for:

• automated cross-tenant access tests
• per-tenant rate limits, so one noisy customer cannot starve the rest
• tenant-aware backups and exports

Those items are invisible in a demo and are exactly what a security questionnaire asks about.

Auth, billing, roles: why are they the boring part that eats the budget?

Authentication, billing and role-based access are unglamorous, mandatory and easy to underestimate. Practitioners often say they absorb something like 40% of early engineering. That is a rule of thumb, not a measured industry figure, and it varies by product.

The reason is edge cases. Sign-up is easy. Password reset, email verification, invitation flows, session expiry, failed payments, plan changes mid-cycle and tax handling are where the days go.

None of this differentiates your product, and every one of those flows is a place customers lose trust if it breaks.

What does the identity layer involve?

At minimum: sign-up and login, email verification, password reset, organisation and user separation, invitations, and roles with permission checks on every endpoint. B2B buyers then ask for SSO via SAML or OIDC and sometimes SCIM provisioning.

Treat SSO as a scoped later feature unless a named customer requires it at signing. Build the user model so organisations, not individual users, own the data. Retrofitting that is painful.

What does billing involve?

Billing is more than a payment form. You need plans, trials, proration, invoices, failed-payment retries, tax, and a sync between subscription state and what the user can access.

Stripe publishes its card pricing, at 2.9% plus 30 cents per successful domestic card charge in the US at the time of writing.

That is a vendor fee on your revenue, separate from the build effort of wiring it in. Its Billing documentation shows how many states a subscription can occupy, which is a fair indicator of the test surface you inherit.

Cost to build a SaaS platform by stage: MVP, v1, scale

Cost rises in steps tied to stage, not smoothly. An MVP proves one workflow, v1 makes it sellable to a team, and scale makes it survivable under load and audit. Fund the stage you are in, not the one after.

The list below describes scope and commercial shape for each stage. It carries no prices, because those are set per project after discovery.

• MVP. Built: one core workflow, tenant isolation, hosted auth, basic roles, one billing path. Deferred: SSO, admin console, analytics, integrations beyond one. Commercial shape: fixed scope, short fixed timeline.
• v1. Built: team features, invitations, plan tiers, audit trail, two or three integrations, monitoring. Deferred: advanced reporting, custom contracts, regional hosting. Commercial shape: fixed scope per release, or a fractional team.
• Scale. Built: SSO and SCIM, compliance work, performance tuning, tenant-level controls, SLAs. Deferred: rarely anything, because this is where deferred items land. Commercial shape: an ongoing team, scoped per quarter.

How does an MVP differ from a prototype?

A prototype can fake the back end. An MVP cannot, because real customers will put real data in it. That means authentication, tenant isolation and billing must work, even if the feature set is narrow.

A fixed scope is the discipline that makes this affordable: it forces the list of "not now" items to be written down before work starts. Anything on that list becomes a candidate for v1 rather than a surprise mid-build.

What does infra run-rate look like at 100, 1,000 and 10,000 users?

Infrastructure cost grows slower than user count at first, then in steps as you add redundancy, background workers and data volume. We have not published first-party run-rate figures for a live product here, so this section describes the steps rather than quoting dollars.

At around 100 users, a single application service and one managed database are usually enough. Cost is dominated by fixed items such as the database instance and a load balancer, not by traffic.

At 1,000 users you typically need a standby database, a job queue, error tracking and log retention. Each is a line item that did not exist before.

At 10,000 users, database size, read replicas, caching and egress start to matter, and cost per user is driven by your heaviest tenants rather than the average one.

Which infrastructure line items surprise teams?

High availability is the first. AWS documents that an RDS Multi-AZ deployment keeps a standby copy in a different Availability Zone, and that standby is a resource you pay for.

Others to look for:

• non-production environments (staging often mirrors production)
• observability tooling priced by data volume
• data transfer out

None of them scale with the number of signed-up users, which is why a flat per-user estimate is misleading.

Price your own architecture with the vendor's calculator, using your own usage assumptions. Re-run it whenever the architecture changes, because a new queue or replica is a new line on the bill.

Build vs assemble: what should you buy off the shelf?

Buy anything that is mandatory but not differentiating: identity, payments, email delivery, file storage, error tracking. Build what customers pay you for. The saving is not only build time but also the security and uptime burden you avoid.

Assembling has costs too. Vendor fees scale with usage, pricing changes are outside your control, and migrating away later is real work if you let vendor concepts leak into your data model.

A practical test: if a vendor's outage would make your product unusable, wrap it behind an interface of your own so you can replace it. If it would only degrade a side feature, call it directly.

What should you build yourself?

Build the domain model, the core workflow and anything where your pricing or permissions logic is the product. If usage-based billing with unusual metering is your business model, off-the-shelf subscription tooling may fit poorly and a custom metering layer can be justified.

Also build the thin layer between vendors and your data. Store your own user and organisation IDs and map vendor IDs to them. That small decision keeps your options open.

What is a large SaaS quote really pricing?

A large quote prices risk, team shape and unknowns as much as features. Read it for what is included, what is assumed, and what is excluded, because two quotes with the same total can describe very different products.

Look for the line items buyers commonly miss:

• security review
• automated tests
• deployment pipeline
• documentation
• handover
• a warranty period

A quote that omits them is cheaper on paper and more expensive later.

Look also for how change is handled. A fixed scope with a clear change process is easier to govern than an open-ended time-and-materials estimate, though it requires a better brief up front.

How do you compare two quotes fairly?

Ask each vendor the same five questions:

1. Which tenancy model is assumed?
2. Which identity and billing providers are assumed?
3. What is excluded?
4. How many releases does the total cover?
5. Who owns the code and infrastructure at the end?

If answers differ, the totals are not comparable. Ask for a written scope that you could hand to another team.

Where can you get help scoping?

If you want a scoped answer for your own product, start with a workflow assessment and ask for a fixed-scope quote.

If you are weighing vendors and want a second view on the build itself, our SaaS development service is where we cover it.