The current article presents a way of practising case formulation using technology augmentation in the context of data-informed psychotherapy. First, we explain how case formulation guides the decision-making processes in psychotherapy and how decisions made under an intuitive clinical judgement can be biased. The use of actuarial methods is pointed out as a way of addressing these biases, mainly through clinical decision support systems based on statistical tools and machine learning algorithms. We present the Trier Treatment Navigator (TTN), a clinical decision support system developed in a University research-based clinical training programme. We show how the TTN can contribute to an initial case formulation and its dynamic adaptations during treatment with a clinical case. Finally, we discuss how case formulation and data-informed psychotherapy are aimed at the same goal: treatment personalisation. We argue that case formulation and data-informed psychotherapy enrich and feedback on each other.