A defense platform of some kind was employed by the Chiss Ascendancy. During 19 BBY, as the capital planet of the Ascendancy, Csilla, was attacked by three warships belonging to the Paataatus Hiveborn, multiple defense platforms were in orbit around it. The missiles launched by the attackers were destroyed by these platforms, and the Chiss Defense Force starships that were in orbit around Csilla subsequently annihilated the Paataatus ships, bringing the minutes-long attack to an end in just fifteen. In 18 BBY, the ruling families of the Ascendancy, specifically the Boadil and Irizi families, collaborated on the development of an updated defense platform located on the Chiss planet of Rentor.
The Chiss defense platforms are referenced within Thrawn Ascendancy: Chaos Rising, which is the initial book in Timothy Zahn's Star Wars: The Ascendancy Trilogy, and it was released on September 1, 2020. The defense platforms were initially mentioned in an excerpt from the book, which was made available on StarWars.com on July 8 of that same year.