This talk addresses the critical need for usecase-specific evaluation of Large Language Model (LLM)-powered applications, highlighting the limitations of generic evaluation benchmarks in capturing domain-specific requirements. It proposes a workflow for designing more reliable evaluatios to optimize LLM-based applications, consisting of three key activities: human-expert evaluation and benchmark dataset curation, creation of evaluation agents, and alignment of these agents with human evaluations using the curated datasets. The workflow produces two key outcomes: a curated benchmark dataset for testing LLM applications and an evaluation agent that scores their responses. The presentation further addresses the limitations, and best practices to enhance the reliability of evaluations, ensuring LLM applications are better tailored to specific use cases.