REST API on a legacy Symfony app for a headless React frontend

Instead of rewriting a Symfony 3.4 events platform, we exposed its existing business logic through 20+ REST endpoints — unblocking a full React migration at a fraction of rewrite cost.

20+ REST endpoints on existing business logic
0 interruptions to live bookings during the build

A culinary events platform wanted a modern React interface, but its business logic lived inside a legacy Symfony 3.4 monolith rendered with Twig and jQuery. The original developer had left the industry, leaving a non-technical founder with a working system and little knowledge of its internals.

The challenge

  • The logic was tightly coupled to Twig templates — there was nothing for a React app to talk to.
  • Symfony 3.4 required real knowledge of older dependency-injection and routing patterns.
  • Live bookings could not stop while the frontend was replaced.

What we did

Rather than rewrite, we built an API layer on top of what already worked:

  • Adapted more than 20 endpoints — orders, restaurants, user profiles — to the exact spec defined by the frontend team.
  • Used JMS Serializer groups to turn existing entities into clean JSON without breaking the legacy web views still in production.
  • Set up a mirrored staging environment where the React developer could test against real data without touching live bookings, iterating on payload formats with us in real time.

The outcome

The React frontend replaced the old interface, the platform kept processing bookings throughout, and the API was delivered in a fraction of the time and budget a full re-platforming would have cost.

“You were fast, very skilled, and went above and beyond what was expected! Highly recommended for any complex Symfony work.” — founder, events platform

A rewrite is rarely the first answer — this is the kind of stepwise path we recommend in our modernisation work.

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industry

Events & hospitality (Netherlands)

tech stack

Symfony 3.4, JMS Serializer, React

service

Modernisation & Upgrades

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