S-Print v4

The story

S-Print is the platform SGP provides to its contractual partners to declare their data and have it checked: the economic activity and jobs created for building the Grand Paris Express, and construction-site safety. It tracks precise contract commitments, such as reserving at least 20% of the amount for small businesses and 10% of the hours for people far from employment.

Version 3 is based on Java and Vue.js. Version 4, which I help build, replaces it with Symfony and API Platform on the server side, TypeScript and React on the interface side. The goal: replace the Excel files companies used to send with a user-friendly entry interface, with controlled reference data, and automate the feed of data into the Cockpit analysis tool. It is also about modernising the technical base, reducing debt and making changes easier.

I'm a development officer in the S-Print team of the Development unit. I rebuild, feature by feature, what version 3 does: React/TypeScript pages and components (company list and search, accident-statistics consultation, economic-footprint lists and forms, contract creation), a reusable API-call mechanism with clean error handling, Symfony service changes and their API tests. I review code, write and run tests, document, and lead the agile ceremonies in turn.

As long as v4 isn't complete, v3 stays in production: so I always have to analyse the existing system to forget nothing. One of my goals with my tutor: contribute to the delivery of version 4.0.0 and take an active part in code reviews.

What I take away

Rebuilding without breaking: understand the old version, rewrite it cleanly, compare field by field. Behind every form field is a real commitment to local jobs and small businesses, so data accuracy is a priority.