Gecko is a rubric-based auto-rater for evaluating generative AI models, available on Google Cloud’s Vertex AI Evaluation Service.Traditional human evaluation of generative models can be slow and costly, hindering development cycles.Gecko offers a customizable and transparent evaluation process for image and video generation models.Gecko's interpretability allows developers to understand model behavior and improve performance.It leverages a rubric-based approach to evaluate image and video generation skills efficiently.Gecko uses semantic prompt decomposition and question-answer generation for evaluation.Evaluation with Gecko involves scoring generated media against question-answer pairs.Gecko is integrated into Vertex AI's Gen AI Evaluation Service for assessing generative models.Setting up Gecko evaluation on Vertex AI involves rubric generation and dataset preparation.Detailed insights and visualizations of evaluation results are provided by Vertex AI Gen AI service.