PHP 8.4 Lazy Objects Power Symfony 8 Boot Performance Gains Up to 25%

PHP 8.4 introduces lazy objects as a native language feature, initializing an object's internal state only when it is first accessed rather than at creation time. Symfony 8 leverages this capability in its dependency injection container, meaning service constructors are executed only when a service is actually used during a request. Prior to PHP 8.4, Symfony relied on runtime-generated proxy classes cached to disk, which added measurable overhead through code generation, file I/O, and autoloading. With native lazy objects, that overhead is eliminated entirely, as PHP's runtime handles deferred initialization without extra classes or cache files. Typical Symfony applications with 200 or more registered services can expect boot-time improvements of 15–25%, with greater gains in large bundle-heavy projects and serverless environments where cold-start latency directly affects operating costs.