Backdrop CMS does not support the default front page setting to be multilingual (one node for each language). Drupal 7 core does not either, but the contrib module i18n does. This feature would be helpful for Backdrop adoption in multilingual environments

However, there's a small workaround, using the redirect function in node settings. Just add a redirection to the default front page, pointing to the intended 2nd language front page node, and make this redirection language aware (2nd language).

GitHub Issue #: 
3500