Once you hit scale there are very few off the shelf solutions. Every major application is going to have some degree of customization involved.
Personally, I maintain a legacy codebase of a propietary application running several distribution centers. New feature requests, bug fixes, integrations, ever-changing business requirements mean its worth having staff on payroll to do it, as the contractor costs to do so are exorbitant.
Personally, I maintain a legacy codebase of a propietary application running several distribution centers. New feature requests, bug fixes, integrations, ever-changing business requirements mean its worth having staff on payroll to do it, as the contractor costs to do so are exorbitant.