Magento 2 - Request Flow / Bootstrap - Magento\Framework\App\Http::launch()

Magento\Framework\App\Http.php

<?php
...

    /**
     * Run application
     *
     * @throws \InvalidArgumentException
     * @return ResponseInterface
     */
    public function launch()
    {
        $areaCode = $this->_areaList->getCodeByFrontName($this->_request->getFrontName());
        $this->_state->setAreaCode($areaCode);
        $this->_objectManager->configure($this->_configLoader->load($areaCode));
        /** @var \Magento\Framework\App\FrontControllerInterface $frontController */
        $frontController = $this->_objectManager->get('Magento\Framework\App\FrontControllerInterface');
        $result = $frontController->dispatch($this->_request);
        // TODO: Temporary solution until all controllers return ResultInterface (MAGETWO-28359)
        if ($result instanceof ResultInterface) {
            $this->registry->register('use_page_cache_plugin', true, true);
            $result->renderResult($this->_response);
        } elseif ($result instanceof HttpInterface) {
            $this->_response = $result;
        } else {
            throw new \InvalidArgumentException('Invalid return type');
        }
        // This event gives possibility to launch something before sending output (allow cookie setting)
        $eventParams = ['request' => $this->_request, 'response' => $this->_response];
        $this->_eventManager->dispatch('controller_front_send_response_before', $eventParams);
        return $this->_response;
    }
    
    ...