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Agencei

Development

SaaS platform development

A SaaS (software as a service) is a hosted application that your customers use by subscription, without installation, each with their own space, data and users. Its design differs from internal software: customer isolation, plan and billing management, self-service onboarding, availability and scalability are at the heart of the product.

Agencei supports software vendors, startups and companies turning know-how into a software product: a first version to validate the market, then industrialization of the platform as customers arrive. We also take over existing SaaS products whose architecture limits growth.

We build these platforms with Next.js, Node.js, PostgreSQL and automated cloud infrastructure, integrating multi-tenancy, subscription billing and observability from the outset.

When do we step in?

Launching an MVP to validate a market

You have identified a need and want to put a product in the hands of the first paying customers quickly, without compromising the future with rushed technical choices.

Turning an internal tool into a product

Software built for your own needs interests other companies. It must become multi-tenant, with secure data isolation, sign-up, plans and billing.

Industrializing a growing SaaS

Customers are arriving, and so are incidents: slowness, risky deployments, no monitoring. We consolidate the architecture and infrastructure without stopping the product.

Adding billing and subscriptions

Plan management, free trials, recurring payments, compliant invoices, proration and plan changes: we integrate Stripe or an equivalent properly.

Meeting enterprise customer requirements

Single sign-on (SSO), audit log, fine-grained roles, hosting in a given region: the features expected by large accounts become necessary.

How we work

  1. 1

    Product scoping and business model

    Definition of personas, key journeys (sign-up, onboarding, daily use), pricing plans and the metrics to track from launch.

  2. 2

    Multi-tenant architecture and security

    Choice of the data isolation model, design of authentication, roles and organizations, backup and encryption strategy.

  3. 3

    MVP development

    Development of differentiating features and standard components (accounts, billing, transactional emails), with automated tests from day one.

  4. 4

    Infrastructure and continuous deployment

    Infrastructure as code, test and production environments, automated deployments, monitoring and alerts.

  5. 5

    Launch and measurement

    Opening to the first customers, tracking activation and retention indicators, quick fixes for friction points.

  6. 6

    Scaling and evolution

    Performance optimization, addition of enterprise features, product evolution driven by real usage.

Technologies we use

  • Next.js
  • TypeScript
  • Node.js
  • NestJS
  • PostgreSQL
  • Redis
  • Stripe
  • Auth0 or Keycloak
  • Docker
  • Kubernetes
  • AWS
  • Terraform

Why choose Agencei?

  • Foundations that do not slow you down

    We know which choices are irreversible (multi-tenant model, identifiers, billing) and which can wait. The MVP moves fast without compromising scale.

  • Product and infrastructure by the same team

    Development, cloud and continuous deployment are designed together, avoiding platforms that work in demos but fall over at the first spike.

  • Experience with standard SaaS components

    Subscription billing, onboarding, organization and invitation management, transactional emails: we have built them before and know where the pitfalls are.

  • Transparency on running costs

    We design the infrastructure with its monthly cost in mind, not only what it makes technically possible.

In brief

What is this service?
Design and development service for SaaS platforms: multi-tenant architecture, accounts and organizations, subscriptions and billing, automated cloud infrastructure and continuous deployment.
Who is it for?
Software vendors, startups and companies launching a subscription product, turning an internal tool into a product or needing to industrialize an existing SaaS.
What problem does it solve?
Bringing a product to market quickly while guaranteeing customer data isolation, reliability and the ability to scale as customers arrive.
How long does it usually take?
Often a few months for an MVP including standard components, followed by continuous industrialization at the pace of growth.
What factors influence the price?
Functional scope of the MVP, complexity of the multi-tenant model and roles, billing needs, security and compliance requirements, level of infrastructure automation.
How does the engagement run?
Product scoping and business model, multi-tenant architecture and security, MVP development with tests, infrastructure as code and continuous deployment, measured launch, scaling and evolution.
What are the risks?
Poorly designed data isolation, uncontrolled cloud costs, an oversized MVP that delays launch, technical debt blocking growth, vendor lock-in.
What alternatives exist?
A single-customer internal tool if resale is not confirmed, a no-code product to test demand before investing, or an extension of an existing platform.

Frequently asked questions

What is a multi-tenant architecture?

It is an architecture where several customers (tenants) share the same application and infrastructure while keeping strictly isolated data. It reduces running costs and simplifies deployments, provided isolation is designed rigorously from the start.

How long does it take to launch a SaaS?

An MVP focused on a clear value proposition often takes a few months, standard components included. Industrialization and enterprise features then continue at the pace of growth.

How do you handle billing and subscriptions?

We integrate a payment provider such as Stripe for plans, trials, recurring payments and invoices, and we synchronize subscription status with access rights in the application.

Can you take over an existing SaaS?

Yes. We audit the code, the database and the infrastructure, then propose a progressive consolidation plan that keeps the service running for your current customers.

Where is the data hosted?

On the cloud infrastructure of your choice, in the region you require, with encryption, backups and logging. We document these elements for your answers to customer security questionnaires.

Tell us about your project

Describe your need in a few lines: we come back to you with a first analysis and the next steps.