Build logs and teardowns from shipping AI-assisted developer tooling and market-data systems.https://joneflow.dev/https://joneflow.dev/blog/backtest-lookahead-bias/https://joneflow.dev/blog/backtest-lookahead-bias/Four places future information leaks into a backtest that uses more than one timeframe — entry price, confirmation alignment, intrabar ordering, and timezones.Tue, 28 Jul 2026 00:00:00 GMThttps://joneflow.dev/blog/llm-stock-analysis-context-contract/https://joneflow.dev/blog/llm-stock-analysis-context-contract/The follow-up to five production failures: how to assemble context so the model cannot confidently describe wrong inputs, and where the boundary sits.Tue, 28 Jul 2026 00:00:00 GMThttps://joneflow.dev/blog/llm-stock-analysis-hallucinations/https://joneflow.dev/blog/llm-stock-analysis-hallucinations/Five real failures from a running market-analysis pipeline — an API that never existed, a buy signal with no price, an inverted gap — and the checks that caught them.Tue, 28 Jul 2026 00:00:00 GMThttps://joneflow.dev/blog/market-data-websocket-reconnect/https://joneflow.dev/blog/market-data-websocket-reconnect/Two disconnects look identical at the socket layer and mean opposite things. Getting the backoff asymmetry right is most of the reliability.Tue, 28 Jul 2026 00:00:00 GMThttps://joneflow.dev/blog/scheduled-jobs-that-stop-running/https://joneflow.dev/blog/scheduled-jobs-that-stop-running/A scheduler edit that touched some weekday entries and not others, the state gaps that revealed it weeks later, and why absence of output is never an alert.Tue, 28 Jul 2026 00:00:00 GMThttps://joneflow.dev/blog/what-this-site-is/https://joneflow.dev/blog/what-this-site-is/Build logs from shipping AI-assisted developer tooling and market-data systems — what gets written here, and what does not.Tue, 28 Jul 2026 00:00:00 GMT