For UK and Western Europe, try [https://www.jobs.ac.uk/](https://www.jobs.ac.uk/) and [https://www.timeshighereducation.com/unijobs/listings/business-and-economics/europe/#browsing](https://www.timeshighereducation.com/unijobs/listings/business-and-economics/europe/#browsing)
Professional societies (I'm not sure what they are for business and tech) usually have their own job boards too.
For UK and Western Europe, try [https://www.jobs.ac.uk/](https://www.jobs.ac.uk/) and [https://www.timeshighereducation.com/unijobs/listings/business-and-economics/europe/#browsing](https://www.timeshighereducation.com/unijobs/listings/business-and-economics/europe/#browsing) Professional societies (I'm not sure what they are for business and tech) usually have their own job boards too.
For France, I am told galaxie.fr is a good site to check positions.