I design and build multi-tenant SaaS platforms that handle real users, real payments, and real growth. Django, PostgreSQL, and a production-tested architecture that scales with your business.
SaaS is not just another web application. It is a product that must serve multiple customers simultaneously, isolate their data securely, handle recurring payments without errors, and scale without requiring a full rewrite every six months. Most generic web developers can build a landing page or a simple CRUD app, but SaaS demands a fundamentally different approach to architecture, data modeling, and infrastructure.
I specialize in building SaaS products from the ground up. As a freelance backend developer based in Barcelona, I have spent years designing multi-tenant systems, integrating subscription billing, and deploying platforms that serve businesses across Europe and beyond. Every SaaS project I take on starts with understanding the business model first and the technology second. Whether you are validating an idea with an MVP or scaling an existing product to thousands of users, I bring the same level of architectural rigor to every engagement.
My clients range from startup founders launching their first product to established companies adding SaaS revenue streams. The common thread is they need someone who understands not just how to write code, but how to build a product that works reliably in production, handles edge cases gracefully, and does not fall apart when traffic spikes or a payment webhook fires at 3 AM.
Every SaaS platform is different, but most share a common set of building blocks. Here is what I deliver across projects:
I do not chase trends. I use a stack that is battle-tested, well-documented, and proven at scale. Every technology choice is driven by the specific requirements of your SaaS product, but the foundation remains consistent across projects:
Django and Django REST Framework form the core of every SaaS backend I build. Django's ORM, migration system, and admin interface accelerate development significantly, while DRF provides a robust foundation for APIs. As a Django developer in Barcelona, I have delivered over fifteen commercial projects using this stack, and I know its strengths and limitations intimately.
PostgreSQL is the database I trust for SaaS. Its native support for schemas makes tenant isolation straightforward, and features like row-level security, partial indexes, and JSONB fields give me the flexibility to model complex domain logic without external dependencies. For caching, session storage, and real-time features, Redis handles the load efficiently.
Celery powers all background processing: sending emails, generating reports, processing webhook payloads, running scheduled billing tasks, and syncing data with external services. Combined with Redis as a message broker, this setup handles thousands of tasks per minute without breaking a sweat.
Docker ensures that the development, staging, and production environments are identical. Every project I deliver includes a Docker Compose configuration for local development and production-ready Dockerfiles. Deployment is typically to Linux VPS or cloud infrastructure behind Nginx, with CI/CD pipelines for automated testing and zero-downtime deploys.
Beyond the core platform, SaaS products need a specific set of features to be production-ready. These are the capabilities I build into every project as needed:
Schema-based or row-based tenant isolation with PostgreSQL. Each customer gets their own secure data environment with zero cross-tenant leakage.
Stripe integration with recurring charges, plan management, trial periods, proration, failed payment recovery, and automated invoice generation.
Granular permissions system with custom roles per tenant. Admins, managers, and regular users each see exactly what they should and nothing more.
Built-in dashboards with key metrics, filterable reports, and one-click export to Excel and PDF. Custom analytics per tenant or platform-wide.
Outgoing webhook system for notifying external services about events. Incoming webhook handlers for Stripe, Telegram, and custom third-party APIs.
Celery-powered task queues for email delivery, report generation, data imports, scheduled billing, and any async operations your SaaS needs.
I do not speak in hypotheticals. Here are real SaaS products I have built, each solving a specific business problem with the architecture and features described above:
A chain of cafes and restaurants needed to replace spreadsheet-based hour tracking with a proper system. I built a SaaS platform with shift management, employee roles, automated payroll calculations, and detailed reporting. Manager dashboards and employee portals with real-time check-in and check-out. The system cut operational costs and eliminated calculation errors entirely.
Five cafes in Barcelona, each operating independently with paper-based records. I built a multi-tenant SaaS platform with PostgreSQL schema-per-tenant architecture, giving each location its own isolated workspace. Features include real-time clock-in and clock-out, automatic overtime detection, paid and unpaid holiday tracking, role-based access for admins and workers, and one-click Excel export for payroll processing. The owners gained instant visibility across all five locations from a single dashboard.
Winessy needed a platform where investors could purchase fractional wine ownership as NFTs, with each token backed by a real bottle stored in Bordeaux City Bond. I built the full backend: real-time pricing analytics, sommelier evaluations, a secondary market for token trading, and physical delivery claims. Stripe integration handles payments, and blockchain provides provenance tracking. A complex SaaS product with multiple user roles, investment portfolios, and regulatory compliance requirements.
SaaS development is a significant investment. Here are the types of clients and situations where my services deliver the best results:
Whether you are pre-revenue or serving thousands of users, I adapt my approach to your stage. Book a free consultation to discuss your product and get a realistic scope and timeline.
Every SaaS project is unique, but these tiers give you a realistic starting point. Final scope and pricing are determined after a discovery session where I understand your business model, target users, and technical requirements.
A focused SaaS MVP typically takes three to five weeks. This includes core functionality, user authentication, basic multi-tenancy, one subscription tier, an admin panel, and deployment. The exact timeline depends on the complexity of your domain logic and integrations required. I provide a detailed estimate after the discovery phase, and I deliver iteratively so you see working software every week.
My primary SaaS stack is Django with Django REST Framework for the backend, PostgreSQL for the database with schema-based multi-tenancy, Redis for caching and real-time features, Celery for background task processing, and Docker for containerized deployment. For payments I integrate Stripe, and for infrastructure I use Nginx with Linux VPS or cloud providers. This stack is proven at scale and I have delivered over fifteen commercial projects with it. You can read more about my technical approach on the blog.
Yes. I regularly help businesses transform existing Django or Python applications into multi-tenant SaaS products. This includes adding tenant isolation, subscription billing, role-based access control, usage analytics, and API endpoints. The migration is done incrementally to avoid disruption to your current users. If your application is built on a different stack, we can discuss the best approach during the initial consultation.
A focused SaaS MVP starts from EUR 3,000 and typically takes three to five weeks. This includes core functionality, user authentication, basic multi-tenancy, one subscription plan, an admin panel, REST API, and Docker deployment. More complex platforms with full multi-tenant architecture, Stripe billing, and analytics dashboards start from EUR 7,000. I provide a detailed fixed-price estimate after a free discovery session, so there are no cost surprises.
Yes. A significant portion of my clients are startup founders launching their first SaaS product. I help translate business ideas into technical specifications, choose the right architecture for the stage you are at, and build an MVP that validates the concept with real users. You do not need a technical background — I handle all technical decisions and explain them in plain language. Communication happens via Telegram, email, or video calls, whatever works best for you.
Tell me about your product idea or business challenge. I will propose an architecture, estimate the timeline, and walk you through the development process. First consultation is free.
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