Key performance metrics to consider when building applications with language models include:
- TTFT: Time taken for the model to generate its first token
- TBT: Interval time between successive tokens
- TPS: Number of tokens the model generates per second
- TPOT: Time required to process and output each token
- Total Latency: Overall response generation time

TTFT and TBT are particularly important for end users and should be the primary focus for user-facing products, as they have the greatest impact on real-world application responsiveness.