B2B SaaS Product Development Agency — MVP to Market Leader
Home/Services/SaaS Product Development
SaaS Product Development

B2B SaaS Product Development Agency — MVP to Market Leader

Brantum builds B2B SaaS products from zero to market leader. We handle the full product lifecycle: strategy and UX, backend and frontend engineering, cloud infrastructure, billing integration, and PLG mechanics — all under one accountable team. We don't just build software; we build software designed to grow itself.

Core Capabilities

B2B SaaSPLGReactNode.jsStripeAWSMulti-tenantSeries A Ready

What We Build

B2B SaaS MVPs (8–14 weeks from brief to production). Multi-tenant SaaS architecture with workspace isolation. Subscription billing (Stripe, Paddle) and usage-based pricing. Self-serve onboarding flows with product-led activation. Analytics dashboards and admin portals. API-first architecture for integrations and marketplace listings.

PLG Built In

Every SaaS product we build has PLG mechanics from sprint one: viral invite loops, freemium tier architecture, usage-based feature gating, onboarding progress indicators, empty state design, in-app upgrade prompts. We do not bolt growth on at the end — it's engineered from day one.

Compliance & Security

SOC 2 Type II readiness by design. GDPR-compliant data architecture (PII isolation, right-to-erasure, data processing agreements). HIPAA-compliant health data systems. Financial data security (PCI DSS scope minimisation). Penetration testing and security review before every launch.

Series A Readiness

Brantum's SaaS builds are designed to survive Series A due diligence. Clean architecture, comprehensive test coverage, production monitoring, runbook documentation, infrastructure-as-code, and a security posture that investors recognise. We've helped 8 clients pass technical due diligence for Series A rounds.

Pricing

SaaS MVP (8–14 weeks): £45,000–£90,000. Full SaaS product (16–28 weeks): £90,000–£200,000. Ongoing retainer (post-launch): from £12,000/month for a dedicated engineering pod. All projects begin with a 2-week, £5,000 Discovery Sprint.

Relevant Case Studies

B2B SaaS: 0 to 1M+ Active Users

340% organic growth18 months100% Ownership

Frequently Asked Questions

How long does it take to build a SaaS MVP?

A focused B2B SaaS MVP (core feature set, authentication, billing, basic admin portal) typically takes 8–12 weeks with a senior team. A more complex MVP with AI features, multi-tenant architecture, or compliance requirements takes 12–20 weeks. The 2-week Discovery Sprint defines the scope precisely.

What's the difference between an MVP and a full SaaS product?

An MVP is the minimum viable product — the smallest set of features that lets you validate product-market fit with paying customers. A full SaaS product includes all the features you need to retain customers and grow: advanced admin, integrations, analytics, API access, and enterprise features. Brantum builds both.

Do you handle SaaS billing and subscriptions?

Yes. We integrate Stripe or Paddle for subscription billing, usage-based pricing, and billing portal. We design pricing tier architecture, implement metered billing, handle proration, and build the upgrade/downgrade flows. Billing is often the most complex part of a SaaS product — we do it properly.

Can you build AI features into our SaaS product?

Yes — AI features are increasingly the differentiator in B2B SaaS. We build LLM integration, RAG pipelines, AI copilots, document processing, and agentic workflows. All implementations are GDPR and SOC 2 compliant by design.

What happens after launch?

Most clients move to a monthly engineering retainer after launch — ongoing sprint work, feature development, performance monitoring, and PLG iteration. We offer SLA-backed maintenance contracts for regulated platforms (FinTech, HealthTech). We also manage the technical due diligence process if you're raising a Series A.

Related Resources

Brantum CTA

Ready to Get Started?

Book a free 30-minute strategy call. We'll tell you exactly what your project needs — no pitch, no commitment.

Book a Call