Hello,
I see that you need a SQL synchronization application, I can do the development work for your project.
I should be upfront about my lack of experience in Freelancer, but I have strong development experience of more than 13 years with C#.Net, I have worked on a variety of projects in web, windows and console application with databases like MS SQL, MySQL, and Neo4j. I have experience in cloud technologies in AWS and Azure if there arises a need for deployment of your application.
I would suggest a windows service, which runs in the background with a configurable synchronization interval.
I would like to know about the size of the database and if the online database is a read-only database to understand the complexity of the application.
Looking forward to hearing from you.
Regard,
Sujith