The transformation of the existing agrifood system towards more sustainable systems requires sociotechnical strategies that can boost radical changes. In Uruguay there is a community of practice committed to the sustainable development of family livestock farming which has developed alternative production practices, that improve the sustainability of farms based on ecological intensification, for more than fifteen years. Co-innovation as a modality of intervention was a fundamental aspect in the results achieved, being the work on farms a key factor, with a very special bond between extensionist and family. Taking this community of practice as a case study, this text characterizes co-innovation as a modality of intervention for farm technical assistance, offering a vision to enhance the scaling of the interventions and contribute to the sustainable transformation of livestock farming. Results are presented on: 1) general characteristics of the intervention modality, 2) stages of work and practices on farms, 3) characteristics of the family-extensionist bond and 4) lessons learned. Finally, key aspects are pointed out to scale co-innovation, in order to contribute to a sustainability transition of Uruguayan family livestock farming.