SaaS MVP to Series A: 0 to 800 Paying Users in 6 Months

The Challenge

A founder came to us with a clear idea, strong domain expertise in HR, and one constraint: she needed a working product for investor demos in 12 weeks.

The product was a workforce analytics tool — aggregating data from multiple HR systems and surfacing insights that HR teams couldn't easily get from their existing stack. It needed to handle multi-tenant data, integrate with 4 third-party APIs, and have a billing system ready from day one.

She'd been quoted 6–8 months and $80,000+ by two other agencies. We delivered in 12 weeks.

How We Scoped the MVP

The first thing we did was challenge the feature list. Founders tend to over-build MVPs. We ran a prioritisation session using a simple framework:

• Must have at launch — without this, the product doesn't work
• Nice to have at launch — adds polish but not blocking
• Post-launch — important but doesn't affect fundraising narrative

We cut the original scope by 40%. What remained was sharp, coherent, and demonstrable.

The MVP included:

• Multi-tenant auth with SSO support (via Auth.js)
• 4 API integrations (BambooHR, Workday, Google Workspace, Slack)
• A data ingestion pipeline that normalised data from all sources into a unified schema
• A dashboard with 12 core analytics views
• Stripe Billing with subscription tiers (monthly/annual, 3 plan levels)
• Role-based access control (admin, manager, viewer)

What we deliberately left out: mobile app, custom report builder, data export, API for customers. All post-launch.

Technical Architecture

Frontend: Next.js with a clean component library built on Radix UI primitives. We chose this over a custom design system to move fast without sacrificing accessibility. Backend: Node.js API services containerised with Docker, deployed on Railway. We chose Railway over AWS for the MVP — it reduced ops overhead significantly while still being production-grade. Data Pipeline: A lightweight ETL pipeline using BullMQ (Redis-backed job queues) to pull, transform, and store data from all integrations on a configurable schedule. Database: PostgreSQL with a carefully designed multi-tenant schema. All tables include a workspace_id column, and Prisma middleware enforces workspace scoping on every query. Auth: Auth.js (NextAuth) with Google SSO, email/password fallback, and magic link login. Enterprise SSO (SAML) was scoped for post-launch. Billing: Stripe with webhook handling for subscription lifecycle events. We used Stripe's Customer Portal to handle plan changes and cancellations — no custom billing UI needed.

The 12-Week Timeline

The Results

At launch: A production-grade SaaS product with real paying customers from day one (the founder had pre-sold 8 annual subscriptions before we finished building). 6 months later: 800+ paying customers across 3 plan tiers. Churn rate under 3%. The product had expanded with 2 additional integrations and the custom report builder (built by the startup's own engineering team, which we helped hire). 8 months later: Series A closed. The founder cited the product's technical robustness and early traction as key factors in investor confidence.

What Made This Work

Scope discipline. Cutting 40% of the feature list wasn't easy, but it's what made the 12-week timeline achievable without cutting corners on quality. No shortcuts on auth and multi-tenancy. These are the foundations everything else builds on. Getting them right in week 1 meant zero architectural rework later. Shipping with observability. We set up Sentry for error tracking, Axiom for logs, and Uptime Robot for availability monitoring before the first user signed up. The founder knew about issues before her customers did. Want to build your MVP the right way? Start a conversation →