SharePoint 2016 Migration and Customization

I currently operate on SharePoint 2016 with customizations using Jsom and I require skilled help to migrate and properly integrate these customizations into a new environment.

The project includes:
- Migration of SharePoint 2016 to SharePoint Online
- Ensuring integration and operation of existing Jsom based customizations
- it has mutiple pages 12 site pages, some pages has datatable, some has forms, 15 approx fields per page,lookups,cascading dropdown, search, logic which sends email for multi level approval-approx 5 levels, 15 list, 5 libraries, data per list 2000 to 25000 items,
pages can be edited by logging into sharepoint designer and manipulate html css js,

for functionaliyy and logic there are different js files ,



I need someone with:
- Solid Experience in SharePoint Migration
- Expertise in Jsom
- Proven track record managing third-party integrations
- ShareGate tool

This project will require careful planning and flawless execution. Please only apply if you have substantial experience in these areas.