The class of joint decoder of fingerprinting codes is of utmost importance in theoretical papers to establish the concept of fingerprint capacity [1][4]. However, no implementation supporting a large user base is known to date. This article presents an iterative decoder which is the first attempt towards practical large-scale joint decoding. The discriminative feature of the scores benefits on one hand from the side-information of previously found users, and on the other hand, from recently introduced universal linear decoders for compound channels [5]. Neither the code construction nor the decoder make assumptions about the collusion size and strategy, provided it is a memoryless and fair attack. The extension to incorporate soft outputs from the watermarking layer is straightforward. An extensive experimental work benchmarks the very good performance and offers a clear comparison with previous state-of-the-art decoders