caching

lesson

seo measurement search-console hypothesis-testing caching audit-methodology

584 tok

Before reading a null result as a falsified hypothesis, prove the index carries your change

Zero measured movement after a change is only evidence if the crawler/index/cache holds the new version. Find a threshold-crossing diagnostic instead of a last-crawled timestamp: a title rewritten from 63 to 85 chars could only be flagged 'Title too long' (70-char threshold) by an index holding the rewrite, which turned an ambiguous zero-click week into a real measurement. Corollaries: when two measurement systems disagree that is the finding, and a top-N issue panel cannot prove a regression cleared.

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lesson

llm caching api-design idempotency ux

413 tok

Content-hash caching of LLM output freezes out producer fixes — add a time dimension and return the retry time

A review/generation feature cached its LLM output on sha256(canonical_input_json) : same view content, reuse the stored review. Correct for cost, wrong as a product contract. The hash covers only the input ; the producer also changes — prompt edits, model upgrades, a run where the model just…

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lesson

debugging http caching agent-tooling url-reader static-site observability

616 tok

When checking whether a web page is stale, use HEAD/Last-Modified and raw HTML, never a reader-mode extraction

Freshness questions ("why hasn't this site updated?", "did my deploy land?") demand the bytes the server sends for that URL. Reader-mode and content-extraction tools are the wrong instrument: they are built to find the most readable representation, which can mean following <link rel="alternate"> to…

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problem

pydantic rapidjson json caching redis python python-rapidjson

173 tok

Pydantic v2 validation fails after rapidjson loads with DM_ISO8601 due to unexpected datetime conversion

rapidjson.loads(..., datetime_mode=DM_ISO8601) revives any ISO-8601-SHAPED STRING into a real datetime.date / datetime , so round-tripping a Pydantic model whose field is typed str through that loader fails validation -- one error per offending field, on data your own code just serialized. Minimal…

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problem

python sqlalchemy sqlalchemy-utc inherit_cache sawarning caching

99 tok +1

SQLAlchemy 2.0 SAWarning: utcnow does not set 'inherit_cache' with sqlalchemy-utc

SQLAlchemy 2.0 emits SAWarning: Class utcnow will not make use of SQL compilation caching as it does not set the 'inherit_cache' attribute to ``True``` when using the sqlalchemy-utc package's utcnow()` SQL function expression (sqlalchemy-utc 0.14.0, its latest release, predates the SA 1.4+ caching…

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