The verdict in three sentences
For a B2B SaaS V1, a shared database with row-level isolation is the right call in 8 cases out of 10: it costs USD 330 to 980 a month in infrastructure up to 200 customers. A database per tenant is only justified when your first contracts demand physical isolation, typically banking, healthcare or government. Budget USD 65,000 to 130,000 for development (about EUR 60,000 to 120,000) and set aside USD 22,000 to 44,000 for SOC 2 or ISO 27001 as soon as enterprise buyers ask for it.
Three isolation models, three cost profiles
The data isolation choice drives infrastructure cost, migration complexity and how easily you reassure an enterprise buyer. It is hard to change after 50 customers, so settle it before the first line of code.
| Criterion | Shared DB, row-level isolation | Schema per tenant | Database per tenant |
|---|---|---|---|
| Infrastructure, 50 customers | USD 220 to 440/month | USD 380 to 760/month | USD 1,600 to 4,400/month |
| Infrastructure, 200 customers | USD 330 to 980/month | USD 870 to 1,950/month | USD 6,500 to 16,300/month |
| Cost per customer | USD 1.6 to 4.4/month | USD 4.4 to 9.8/month | USD 33 to 82/month |
| Schema migration | 1 operation | N scripted operations | N databases to migrate |
| Cross-tenant leak risk | Medium, controlled by RLS and tests | Low | Very low |
| Development premium | Baseline | +10 to 15% | +20 to 30% |
| Best fit | SMB, volume | Mid-market, sensitive data | Banking, health, public sector |
These are 2026 order-of-magnitude figures on AWS ap-southeast-1 (Singapore), managed PostgreSQL with high availability. A hybrid model is common: shared database for most customers, dedicated database sold as an Enterprise option at USD 550 to 1,650 a month. Singapore's PDPA does not force local hosting, but regulated buyers under MAS guidelines often expect data to stay in-region.
V1 development budget
Multi-tenancy adds building blocks that early estimates forget: organisations and roles, subscription billing, audit log, per-tenant data export, an isolated staging environment.
| Component | Range | Note |
|---|---|---|
| Multi-tenant core, organisations, roles, invites | USD 11,000 to 20,000 | SAML SSO optional: +USD 4,400 to 8,700 |
| Core product feature | USD 27,000 to 60,000 | Depends on domain complexity |
| Stripe billing, plans, quotas | USD 5,500 to 11,000 | Stripe Singapore fee 3.4% + SGD 0.50 per card |
| Audit log and data export | USD 3,300 to 6,500 | Required by IT buyers in 2026 |
| Infrastructure as code, CI/CD, monitoring | USD 6,500 to 13,000 | Terraform, alerts, tested backups |
| Isolation tests and initial pentest | USD 4,400 to 9,800 | 5-day external pentest |
| V1 total | USD 65,000 to 130,000 | 4 to 6 months |
SOC 2 or ISO 27001: when and how much
Singapore startups selling to US customers meet SOC 2 Type II requests, while European and Asian enterprises lean toward ISO 27001. The USD 22,000 to 44,000 budget covers the compliance platform (USD 8,700 to 16,300 a year), the external audit (USD 11,000 to 22,000) and advisory. Expect 6 to 9 months. Below 30 customers, a well-filled security questionnaire and a public Security page often suffice; beyond that, no certification blocks contracts above USD 22,000 a year.
Decisions that blow up the cloud bill
Three mistakes keep coming back: a Kubernetes cluster for the V1 (USD 1,600 a month before the first customer), logs kept forever, and oversized staging databases. A V1 runs well on managed containers and a 2-vCPU PostgreSQL instance.
Mini case study
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Wei Ling, CTO of a Singapore startup building scheduling software for accounting firms, targets 150 customers at USD 315 a month. She picks the shared database with RLS: infrastructure at USD 710 a month, or USD 4.7 per customer, barely 1.5% of monthly revenue of USD 47,250. A database per tenant would have cost about USD 9,800 a month, 20% of revenue. The V1 is priced at USD 92,000 over 5 months. She reserves USD 30,000 for SOC 2 at month 12, when the first regional firm networks ask for it.
FAQ
Can we move from a shared database to per-tenant databases later?
Yes, if the tenant ID is present in every table and query from day one. Moving one customer to a dedicated database then takes 2 to 5 days, about USD 1,300 to 3,800.
Must we host in Singapore to sell to Singapore enterprises?
PDPA allows overseas transfers with safeguards, but 30 to 40% of regulated buyers expect in-region hosting. AWS ap-southeast-1 typically costs 8 to 12% more than US regions.
How many developers for a multi-tenant V1?
A team of 2 to 3 developers plus a tech lead delivers a V1 in 4 to 6 months. Agency day rates in Singapore range from USD 600 to 950.
What cost per customer should a healthy SaaS target?
Infrastructure should stay under 5 to 10% of recurring revenue. At USD 110 a month per subscription, under USD 5.5 per customer is realistic on a shared database.
Is row-level isolation secure enough?
With database-level RLS policies, automated cross-tenant access tests and a pentest, it passes most audits. Breaches almost always come from application code, not the model.
Let's scope your project. Share your product roadmap and we will price your multi-tenant V1, architecture, indicative budget between USD 65,000 and 130,000 and projected infrastructure cost at 200 customers. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
