Ultimately from French plate-forme, possibly through a Slavic language like Russian платформа (platforma) or Polish platforma.
Further reinforced by English platform.
פְּלַטְפוֹרְמָה • (platfórma) f (plural indefinite פְּלַטְפוֹרְמוֹת, singular construct פְּלַטְפוֹרְמַת־, plural construct פְּלַטְפוֹרְמוֹת־)