An engineering backlog lists the items that have been prioritized by the engineering team in the current sprint.
Engineering backlogs are used differently by different agile development teams. It can be a more precise version of the product backlog, containing the individual development tasks required to complete a work-item Alternatively, it could be a list of suggestions from developers to improve the product, which will be processed by the product owner into the main product backlog during the sprint. In some instances, an engineering backlog could simply be a list of open bugs.