When Context Caching Didn't Lower My Gemini Bill — Field Notes on Measuring the Real Hit Rate
When Context Caching is enabled but the Gemini API bill barely drops, this field note measures the real hit rate from usage_metadata, separates TTL churn from fragmentation, and walks through a staged recovery.
When a Prompt That Worked in AI Studio Quietly Breaks Over the API — Field Notes on Measuring the Difference
A prompt that behaves perfectly in AI Studio returns an empty string or a 404 the moment you call the Gemini API from your own code. Instead of eyeballing the two, here is a small harness that records the config diff plus finish_reason, token usage, and the model name the server actually resolved — so you can isolate the cause by layer.
When Gemini × Qdrant Hybrid Search Was Quietly Losing Recall — Field Notes on Instrumenting RRF Weights and Sparse-Vector Drift
Run Gemini embeddings with Qdrant hybrid search in production and your dashboards stay green while recall quietly slips. These field notes show how to catch it with measurement — RRF weights, sparse-vector drift, missing payload indexes — and protect it with a quality budget.
Is Anyone Actually Using Your Gemini Feature? Measuring Acceptance, Regeneration, and Edit Distance
Token charts will not tell you whether users embrace a Gemini-powered feature. A practical design for measuring acceptance rate, regeneration rate, and edit distance with Swift and BigQuery, with two weeks of real numbers.