CoProFlex Case Study: A Vertical Syndic SaaS

The syndic problem and why a vertical SaaS

Condominium management is one of those trades where a generic tool does not go the distance. A firm administers several buildings on behalf of co-owners who vote a budget at the general meeting, fund the charges through quarterly fund calls and expect rigorous financial reporting. The trade vocabulary is precise and structuring: condominium lot, ownership share, allocation key, ALUR works fund, provisional budget, fund call, co-owner share, management mandate. A SaaS that ignores this lexicon misses the business, and a spreadsheet buckles by the second building under management.

The most structuring constraint is accounting. Each condominium keeps autonomous books, with its own dedicated chart of accounts (France's 2005 accounting decree imposes a specific nomenclature), its expense and income accounts and a strict separation of funds. A syndic managing forty buildings therefore keeps forty distinct sets of books, which a generic tool can neither compartmentalize nor reconcile cleanly. The regulatory framework adds its own layer: France's ALUR law of 2014 requires a secure extranet for every co-owner, digitized documents and a mandatory works fund, requirements the ELAN law and more recent texts extended, notably by allowing general meetings to be held remotely.

It is precisely this observation that justifies a vertical SaaS over a horizontal product. Vertical software models a specific trade in depth, where a generic tool aims wide and stays shallow on every case. For a syndic, that changes everything: allocating charges by lot and by key, automatically distributing expenses across co-owner shares or holding a digitized meeting cannot be configured: they have to be designed. This trade-first product logic also pays off in visibility, since GenOptima measures 4.2 times more AI citations for semantically complete, well-structured content, and, by extension, data, which is exactly what a tool faithful to its domain produces.

The operational consequence is stark. A property manager who tracks files across an assortment of non-specialized tools spends considerable time re-entering, reconciling and double-checking data that should flow on its own. It was from that observation that CoProFlex was born, one of the two vertical SaaS products Propulseo built in-house alongside DocAgora (medical), on ten years of experience and more than 50 projects delivered. As long as condominium-specific flows are not modeled in the tool, the business stays under strain, whatever the quality of the generic software chosen.

The CoProFlex solution: multi-tenancy, syndic accounting and a portal

CoProFlex answers this problem with three technical and functional pillars, designed together from the start rather than stacked up over time.

The first pillar is the multi-tenant architecture. A syndic SaaS hosts, on a single platform, the accounting of dozens of condominiums and the data of hundreds of co-owners: compartmentalization is not an option, it is the condition of trust. CoProFlex rests on Supabase, whose Row Level Security (RLS) policies guarantee that a query can never return data belonging to a condominium other than the one the authenticated user has rights to. This compartmentalization is not handled in application code, where a flaw would always be possible, but directly in the database, as close to the data as it gets. The full stack follows the Propulseo standard: Next.js and strict TypeScript for the application, Supabase for the database and authentication, Stripe for billing and subscriptions, Resend or Brevo for transactional notifications, all deployed on Vercel.

The second pillar is syndic accounting. CoProFlex models a repository of lots, allocation keys per type of charge and automatic distribution of expenses across co-owner shares, condominium by condominium. The voted provisional budget, quarterly fund calls, arrears tracking and financial reporting all live there in autonomous, auditable books. The third pillar is the co-owner portal required by France's ALUR law: every co-owner accesses their documents, their fund calls and their meeting minutes, without ever seeing those of another condominium, which closes the loop with the RLS compartmentalization. This requirement of compliance and isolation also explains part of the budget, since a custom SaaS of this kind runs between EUR 40,000 and 300,000.

Lessons that transfer to any vertical SaaS

Beyond the syndic trade, CoProFlex illustrates four principles we find on every successful vertical SaaS, from medical (DocAgora) to productivity. They hold for any founder torn between a horizontal product and a deeply trade-specific tool.

1. Model the business, not the interface. Value does not come from one more screen but from fidelity to the real processes: for CoProFlex, charge allocation by key and per-condominium accounting. A vertical SaaS is judged on its ability to hold the regulatory core of the trade, not on its facade.
2. Decide multi-tenancy at the first line. Data isolation with Supabase and RLS is designed at the schema level, never as a patch. On a SaaS sold to several clients, it is the non-negotiable technical condition of trust and GDPR compliance.
3. Ship an MVP that holds one flow end to end. A scope that fully covers accounting and fund calls beats a dozen half-wired functions. A market-ready SaaS MVP generally runs between EUR 40,000 and 80,000, multi-tenant architecture and Stripe billing included.
4. Treat monetization as a product building block.Stripe handles subscriptions, recurring payments and invoices with no risky homemade system. On a subscription SaaS, billing is not a final add-on but a function designed with the rest.

These principles have a direct economic consequence. A well-designed vertical SaaS compounds over time: it absorbs new clients and new obligations without a full rebuild, which protects the initial investment. This asset logic also applies to the data produced, where SE Ranking measures a +22 percent visibility gain for players who exploit original, well-kept data, and where Authoritas observes that 53 percent of the sources cited by AI are less than six months old. A trade product kept current with regulation stays relevant and citable over time, while a frozen tool falls behind.

For a syndic firm or a property manager, the lesson from CoProFlex extends naturally toward a neighboring question: do you need a commercialized SaaS or an internal tool dedicated to your own organization? That is the whole point of our page on custom real estate and syndic ERP software, which details the same business flows from the angle of a tool owned by the firm rather than sold by subscription.

The budget of a vertical SaaS like CoProFlex

How much does a vertical SaaS comparable to CoProFlex cost? The range is wide because it depends on the functional scope, the number of integrations and the level of security required. A custom SaaS runs between EUR 40,000 and 300,000, and a market-ready MVP most often comes in between EUR 40,000 and 80,000, with multi-tenant architecture, Stripe billing and scalability built in from the start. The block below reflects these ranges as Propulseo applies them on real projects.

Several factors move the cursor within that range. The first is the number of modules: on a syndic SaaS, accounting and fund calls form a foundation, while digitized general meetings, works tracking and rental management come on top. The second is the volume of integrations (accounting, banking or electronic signature) each of which requires specific development. The third is the level of compliance and traceability expected, particularly high when handling the financial and personal data of hundreds of co-owners.

The approach we recommend, proven on CoProFlex as on DocAgora, is to first ship an MVP that holds one complete flow end to end, then extend in increments. This spreads the investment over time, validates the market before committing to the top of the range and lets you prioritize what brings the most value. This incremental logic mirrors that of an interface guiding the user toward the next useful action, where Unbounce measures 13.5 percent conversion for a single-CTA landing page versus 10.5 percent with multiple prompts: a product, like a page, gains by concentrating attention rather than scattering it.

The free Propulseo diagnostic exists precisely to place your project within this range. We scope the MVP, list the integrations essential at launch and those that can be deferred, then produce a detailed quote broken down by lots. As with CoProFlex, the goal is to reach a sellable, reliable product quickly rather than funding an oversized platform all at once, in a trade where accounting and regulatory rigor leaves no room for approximation.