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Convicts follow-up ERP with Xano & WeWeb

Business Apps
Groupe SOS tackles ex-convict reintegration challenges. Their past manual system hindered progress. A custom WeWeb & Xano solution by streamlines workflows: track attendance, personalize support, facilitate scheduling with reminders, and generate data-driven insights to improve reintegration success rates.


SOS Groupe has numerous activities, with over 750 entities and 20,000 employees and an annual budget of more than a billion dollars. One of their branches manages the social and psychological follow-up of convicts in France. They organize meetings with professionals (therapists, social workers, external lecturers, facilitators, etc.), providing up to 11 hours per week of service to hundreds of convicts across France. These activities are billed monthly to the French Ministry of Justice, incorporating precise and complex validation workflows.

Managing hundreds of weekly meetings and financial reports with Microsoft Excel and Outlook proved challenging. Administrative workers spent countless hours each month validating and preparing invoices, and several back-and-forth loops with the Ministry of Justice were necessary just to finalize the paperwork.


There is clearly no existing out-of-the-box SaaS tool to meet the specific needs of SOS Groupe. Consequently, the decision was made to develop software capable of managing meetings while respecting judicial constraints (some convicts are prohibited from meeting) and personal obligations (work, studies, etc.). This software aims to reduce no-shows by sending notifications via email and SMS, but its most critical function is to generate invoices that incorporate numerous complex business rules. These include transport time, different types of meetings, reimbursement for expenses like rentals, and aggregations for regional and national invoices, all within a structured validation workflow that includes regional approvals and proof of each hour spent.

For implementation, we opted to use WeWeb for the front-end and Xano for the back-end. WeWeb was chosen because it offers robust management of complex calendar views necessary to display meetings for each professional or beneficiary. Xano was selected over Supabase due to its superior handling of the numerous intricate business rules and the generation of invoices.

Selecting the right tools: WeWeb and Xano

When we first met with Vincent, the IT Director at SOS Group, we quickly recognized the classic pattern of a successful low-code project:

  • Extensive usage of Excel and Google Sheets.
  • Complex validation workflow requiring several iterations over each invoice to be ready.
  • Countless hours spent on low-value tasks, such as verifying whether all professionals had actually met with the convict
  • High administrative pressure, as the government prefers to allocate funds to convict rehabilitation rather than administrative tasks.

After a first workshop lasting about two hours, we discovered all the main features and potential complexities of this project:

  1. A complex calendar interface to assist admins in planning around 2000 meetings per month.
  2. Advanced back-end rules engines due to many constraints applied to convicts (e.g., work schedules, day parole, restrictions on meeting other convicts, special law enforcement meetings)
  3. Advanced reporting needs with complex tables.
  4. Exporting invoices in CSV and PDF formats.
  5. Mobile accessibility.

Based on these requirements, we initially considered Retool, WeWeb, and Plasmic for the front-end. Plasmic was ruled out as it required too much effort in building components and maintaining the front-end (at that time, Plasmic was primarily a react-components design studio). We also eliminated our preferred tool, Retool, due to its lack of an advanced calendar component and its cost-prohibitive pricing model (Retool uses a per-user-seat pricing model, incompatible with SOS Group's careful budget considerations). Thus, we selected WeWeb, which offered a flat-fee cost while providing a fully capable front-end platform.

For the back-end, we had to pass over our favored Supabase because we needed to create complex business logic and be able to iterate over it quickly. Therefore, we switched to Xano, the most advanced low-code back-end platform in the world.

How we've built a low-code product with WeWeb and Xano

During the first workshops, we began by observing the existing processes and tools used by SOS Group employees. This included analyzing all existing invoices, XLS files, emails, and documents that supported their work.

We then started designing the data model: meetings, convicts, professional users, invoices, invoice lines, etc. We quickly designed tables in Xano and automatically created the CRUD API endpoints. As soon as the first tables were ready, we immediately designed basic front-end screens to create, list, and search for basic items like convicts, invoices, and meetings.

Data model of SOS Group in Xano

We then spent three weeks iterating over the most advanced and complicated feature: meeting planning. Planning sessions are always stressful as we need to consider multiple dimensions: scheduling for professionals, convicts' constraints, and legal obligations (convicts have different follow-up obligations ranging from 2 hours per week to 11 hours per week).

We needed to carefully adapt to the process, but also provide enhancements in how planning sessions were organized, as new tools and optimizations were possible. A lot of rework and changes were made during those weeks. Fortunately, with WeWeb and Xano, rework costs are minimal. We can iterate as much as necessary to create the most adapted, tailored user journey for the professionals and admins of SOS Group.

Once done with planning, we focused on the invoice generation process, where we basically take all meetings from a given region, prepare a draft invoice with numerous pricing rules (depending on the nature of the meetings, their duration, number of professionals, transport time, and meeting location). The draft invoice then has to be validated by local government representatives. Once locally validated, regional invoices can be consolidated nationally, with additional custom lines to be sent to the national government instances for final validation.

Each invoice must be accompanied by detailed reports and proof of each meeting—a not so fun part.

Finally, the most exciting part was the last weeks of the project where we iterated with teams to add numerous small features that made everyone's lives easier:

  • SMS and email notifications to convicts to prevent no-shows.
  • Service-wide reporting to help with adjusting the number of hired professionals.
  • Financial reporting to assist with accounting.
  • Beautiful PDF templates for calendars, invoices, and listings.
  • An automatic planning engine to assist with long, tedious planning sessions.


By implementing custom software, we eliminated many human factor errors, cut thousands of hours of needless work for admins, and allowed professionals more time to help convicts reintegrate into society instead of handling paperwork. The project was built with the users, an essential aspect as relying on highly visual tools like WeWeb provided an unmatched opportunity for co-building sessions. And it was a success, as you can see—the app usage skyrocketed with several hundred API calls per hour, demonstrating intensive user engagement.

One challenge that took a considerable amount of time was PDF generation. So here's a piece of advice: don't try to do it yourself or rely on CSS Media Print of browsers. You will face numerous issues. A strong recommendation from Code.Store: we used Docugenerate, a simple yet powerful tool that allows uploading DOCX templates with variables and then uses a straightforward API call to generate PDFs on the fly.

We spent three weeks trying to make PDF generation work by ourselves. That could have been avoided.

WeWeb and Xano are well-integrated tools. One regret with WeWeb was the lack of out-of-the-box components available in Retool or Superblocks. But maybe their roadmap will address our complaints soon.

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