Interventions aimed at increasing psychological resilience are an important factor in reducing recidivism in young people. However, little is known about how practitioners understand, apply, and assess the efficacy of the interventions they deliver. This knowledge gap is concerning as case workers are at the forefront of intervention delivery, where intervention success has wide implications for the young person and society. To provide some of the first evidence in this area, we conducted in-depth semi-structured interviews with 12 Youth Justice case workers based in Wales (UK). We used reflexive thematic analysis to examine four pre-conceived key themes. The first theme involved understanding what resilience is in young people along with the psychological factors that promoted resilience and psychological factors that undermined it. The second theme revolved around intervention strategies used to develop resilience in young people. The third theme focused upon intervention delivery, and the final theme related to intervention outcomes that included behavioral and psychological changes. Our findings offer some of the first evidence into effective psychological based resilience interventions, methods of delivery, psychological and behavioral changes related to desistance from a case workers perspective. Potential future considerations for interventions relating to youth who continue offending are discussed.