Custom SaaS development in Denmark, from people who build their own platforms

What does it take to build a SaaS platform?

Building a SaaS platform requires four things: a data model with tenant isolation so each customer’s data stays separate; a role and permission system; subscription and billing logic that handles upgrades and cancellations; and an operations setup with hosting, monitoring and backups. With a focused scope, a first version can be live within weeks, after which the platform is extended step by step.

What you get

A SaaS platform is more than a web app. These are the concrete deliverables in a typical SaaS engagement with us:

• 01

  A production-ready SaaS platform

  A full platform built in TypeScript/Next.js with a Rust or Node backend and PostgreSQL, ready for real paying customers, not a prototype.

• 02

  Multi-tenant architecture

  Tenant isolation at the database level, roles and permissions, and an onboarding flow so new customers can be created without manual work.

• 03

  Subscription and billing logic

  Plans, trials, upgrades and invoicing integrated with a payment provider, designed together with the data model, not bolted on afterwards.

• 04

  EU hosting and a GDPR-first data model

  Your data is hosted in the EU, and the data model is designed with data minimisation and deletion in mind from day one.

• 05

  CI/CD, monitoring and backups

  Automated deployment, error monitoring and backups, handed over with the rest of the platform.

We operate what we build, including our own platforms

Most agencies hand over the code and move on. We build and run our own SaaS platforms, so we know the difference between code that looks finished and code that can actually be operated.

• 

  In development

  Unios

  A multi-tenant SaaS platform for student organisations with a site builder, member management and roles across independent organisations. In development, with IBP Union as the intended first tenant.

  • Rust / Axum
  • SQLx
  • PostgreSQL
  • React
  • Vite
  • Astro

• docubotai.app

  

  In beta

  DocubotAI.app

  An AI-powered documentation platform in beta. We handle operations, monitoring and ongoing development ourselves.

  • Next.js
  • TypeScript
  • Supabase
  • Google Gemini

Decisions about architecture, hosting and monitoring are not theory to us, they are things we live with every day on our own platforms.

Multi-tenant architecture is our home turf

The hardest part of SaaS is rarely the visible features, it is keeping many customers safely on one codebase. This is where we spend most of our engineering judgement:

• 01

  Tenant isolation

  Each customer’s data is kept separate at the database level, so a bug in one tenant never leaks data into another.

• 02

  Roles and permissions

  Flexible access control (owners, administrators and members) designed so it can be extended without rewriting the codebase.

• 03

  Subscription logic

  Plans, per-plan limits and payment flows designed together with the data model instead of being glued on afterwards.

EU hosting and GDPR from day one

• Your platform is hosted in the EU, and the data model is designed GDPR-first: personal data is minimised, kept separate from other data, and can be deleted without breaking the system. Access is controlled through roles and permissions.

• We document where data lives, who can access it, and how it is deleted, the technical foundation for your data processing agreements. We do not claim certifications; we build so that your compliance work rests on facts.

How we work

The same four-step model we use on every project, fixed quote, weekly demos, no surprises:

1. Scoping call

   We go through your idea, users and requirements, and tell you honestly what makes sense to build first.

2. Fixed quote within 48 hours

   You get a fixed quote with scope, price and timeline within 48 hours of the call.

3. Build with weekly demos

   You see progress every week on a running version of the platform, not in status reports.

4. Delivery + operations

   The platform goes into production, and we can take care of operations, monitoring and further development afterwards.

Numbers you can check

• You get a fixed, written quote within 48 hours of the scoping call.

• Along the way you see working software at weekly demos.

• You talk directly to the person who writes your code.

• TwinCurrent has received a Mikrolegat grant from Fonden for Entreprenørskab (the Danish Foundation for Entrepreneurship).

SaaS platforms we have built

• 

  In development

  Unios

  Multi-tenant SaaS for student organisations, built by TwinCurrent and in development.

  • Rust / Axum
  • SQLx
  • PostgreSQL
  • React
  • Vite
  • Astro

• docubotai.app

  

  In beta

  DocubotAI

  AI documentation platform in beta at DocubotAI.app.

  • Next.js
  • TypeScript
  • Supabase
  • Google Gemini

What affects the price?

We do not publish list prices, because no two SaaS platforms are alike. What actually drives the price is:

• 01

  Scope

  The number of modules and flows in the first version. A sharp first scope is the single biggest lever for keeping the price down.

• 02

  Integrations

  Payment providers, logins, external APIs and existing systems the platform has to work with.

• 03

  Complexity

  Multi-tenant requirements, roles and permissions, real-time features and the amount of business logic.

You get an estimate within 24 hours, and a fixed written quote within 48 hours of the scoping call.

Get an estimate within 24 hours

Frequently asked questions about SaaS development

• What does it cost to develop a SaaS platform?

  The price depends on three things: scope (how many modules the first version contains), integrations (payments, logins, external systems) and complexity (multi-tenant requirements, roles and business logic). We do not publish list prices because no two SaaS platforms are alike, but you get a fixed quote within 48 hours of a scoping call.

• How long does it take to develop a SaaS platform?

  The honest answer is that it depends on scope, and the delivery date is in the quote. A full platform depends on scope: multi-tenant features, payment flows and integrations are typically built in stages over several iterations. That is why we recommend starting with a focused first scope, getting real users on the platform, and extending from there, with weekly demos so you can see progress at all times.

• Can you take over an existing SaaS platform?

  Yes. We start with a review of the code, architecture and operations, fix the most critical issues first and lay out a plan for further development. Each step is quoted at a fixed price.

• How do you handle GDPR in SaaS development?

  We host in the EU and design the data model GDPR-first: personal data is minimised, kept separate from other data, and can be deleted without breaking the system. Access is controlled through roles and permissions, and we document where data lives and who can access it, the technical foundation for your data processing agreement. We do not claim certifications; we build so that your compliance work rests on facts.

• Which technologies do you build SaaS platforms with?

  Frontend in TypeScript and Next.js, backend in Rust (Axum) or Node/TypeScript, and PostgreSQL as the database: the same stack our own platform DocubotAI (in beta) runs on, and that Unios, our multi-tenant platform in development, is built on. We deliberately choose proven technology that other developers can take over, rather than exotic choices that lock you in to us.

• Do we own the code and the platform?

  Yes. You own the code, the data and the infrastructure accounts. Everything can live in your own GitHub organisation and your own hosting accounts, and there is no lock-in: if you operate the platform yourself or switch vendors, you take everything with you. After handover we stay available for changes and fixes, quoted per task.