File structure

<magento-install-dir>/
    ├── app/
            └── code/ (1)
                    └── <VendorName>/ (2)
                            └── Import/ (3)
                                    ├── registration.php (4)
                                    └── etc/ (5)
                                            ├── di.xml (6)
                                            ├── config.xml (7)
                                            ├── module.xml (8)
                                            └── adminhtml/ (9)
                                                   └── system.xml (10)
1 Magento directory <magento-install-dir>/app/code/ (home of the custom Magento module)
2 Name of the company/vendor or developer of the module
3 Code base of your custom module (Folder name is the name of your module)
4 File that registers the module in the system
5 Module configuration file directory
6 Plugin settings, virtual types, rewriting models
7 Default values for fields in a store configuration
8 It contains the name and version of the module, as well as any dependencies. Load order in your component
9 Configuration files that apply only to the admin panel
10 Building a settings page Stores > configuration

The Pacemaker import functionality is entirely based on the Symfony framework and therefore there must be at least one DI configuration that allows us to override default classes.

The configuration file must be located in the <magento-install-dir>/app/code/<MyProject>/Import/symfony/Resources/config/services.xml directory

<magento-install-dir>/
    └── app/
            └── code/
                    └── MyProject/
                            └── Import/
                                    ├── registration.php
                                    ├── etc/
                                    │      └── di.xml
                                    │      └── config.xml
                                    │      └── module.xml
                                    │      └── adminhtml/
                                    │               └── system.xml
                                    ├── Observers/ (1)
                                    │       └── ProductWebsiteObserver.php (2)
                                    └── symfony/
                                             └── Resources/
                                             └── config/
                                                     └── services.xml (3)
1 Observer directory
2 Custom observer class file
3 services.xml containing the observer override configuration see code below