Self-hosted data systems documented in the open. Build logs, engineering concepts, and process notes by Anthony Pena.https://frogwebp.com/en-ushttps://frogwebp.com/log/the-first-one/https://frogwebp.com/log/the-first-one/I didn't wait until I was ready. I decided, and then I moved.Sat, 20 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/refresh-materialized-view-concurrently/https://frogwebp.com/log/refresh-materialized-view-concurrently/The incremental refresh, and the one mistake that turns it into a full rewrite.Fri, 19 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-idempotent-elt-pipeline/https://frogwebp.com/log/spectrum-idempotent-elt-pipeline/Three committed phases that make re-runs produce exactly the right result.Thu, 18 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-jsonb-staging-ingestion/https://frogwebp.com/log/spectrum-jsonb-staging-ingestion/Why the staging table stores event payloads as JSONB, not typed columns.Wed, 17 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-stale-alert-replay/https://frogwebp.com/log/phronis-stale-alert-replay/Stale alerts surviving in a topic, replaying into a fresh run.Tue, 16 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-cluster-ip-bind/https://frogwebp.com/log/phronis-cluster-ip-bind/A networking lesson about pod interfaces versus Service IPs.Mon, 15 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-init-container-localhost/https://frogwebp.com/log/phronis-init-container-localhost/Init containers run to completion before the main one starts, so 'localhost' is empty.Sun, 14 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-em-dash-powershell/https://frogwebp.com/log/phronis-em-dash-powershell/How one Unicode character became a syntax error 5,000 miles from where it was typed.Sat, 13 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-mcp-server/https://frogwebp.com/log/phronis-mcp-server/'Which agent is misbehaving?' Answered in plain English over RisingWave.Fri, 12 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-self-hosted-amplitude-postgresql/https://frogwebp.com/log/spectrum-self-hosted-amplitude-postgresql/Kicking off the Spectrum build: why I went all-in on SQL for product analytics.Thu, 11 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/boring-stack-on-purpose/https://frogwebp.com/log/boring-stack-on-purpose/On depth over hype, and the quiet discipline of staying.Wed, 10 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-now-concurrently-refresh-bug/https://frogwebp.com/log/spectrum-now-concurrently-refresh-bug/How one timestamp turned an incremental refresh into a full table rewrite.Tue, 09 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/incremental-materialized-views/https://frogwebp.com/log/incremental-materialized-views/The difference between 'recompute on a timer' and 'update as data arrives.'Mon, 08 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/star-schema-vs-snowflake/https://frogwebp.com/log/star-schema-vs-snowflake/Both are dimensional models. The difference is how far you normalize.Sun, 07 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-analytics-pure-sql/https://frogwebp.com/log/spectrum-analytics-pure-sql/The analytics views that power the dashboards: no Python, no dbt, just SQL.Sat, 06 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-realtime-circuit-breaking/https://frogwebp.com/log/phronis-realtime-circuit-breaking/Detect and halt a runaway agent in under 500ms, before the blast radius grows.Fri, 05 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-semantic-search-kickoff/https://frogwebp.com/log/contextflow-semantic-search-kickoff/Ask a question in plain English; get ranked answers with page provenance in under 2 seconds.Thu, 04 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-sessionization-sql/https://frogwebp.com/log/spectrum-sessionization-sql/Grouping raw events into sessions with a 30-minute inactivity gap, no Python required.Wed, 03 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-ab-experiments-wilson/https://frogwebp.com/log/spectrum-ab-experiments-wilson/Computing statistically sound confidence intervals for conversion rates without leaving PostgreSQL.Tue, 02 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/bugs-documented-in-public/https://frogwebp.com/log/bugs-documented-in-public/The failures aren't the embarrassing part of the portfolio. They are the portfolio.Mon, 01 Jun 2026 00:00:00 GMThttps://frogwebp.com/log/schema-registry-data-contracts/https://frogwebp.com/log/schema-registry-data-contracts/Data contracts enforced at the broker, not hoped for in a code review.Sun, 31 May 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-imds-saga/https://frogwebp.com/log/phronis-imds-saga/A multi-session debugging story that came down to s3.access.key.id vs s3.access.key.Sat, 30 May 2026 00:00:00 GMThttps://frogwebp.com/log/circuit-breaker-pattern-ai-agents/https://frogwebp.com/log/circuit-breaker-pattern-ai-agents/A classic resilience idea, pointed at a new kind of runaway process.Fri, 29 May 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-unknown-dangerous-row/https://frogwebp.com/log/spectrum-unknown-dangerous-row/Why a synthetic fallback bucket quietly corrupts tenant metrics.Thu, 28 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-xcom-size-limit/https://frogwebp.com/log/contextflow-xcom-size-limit/A silent empty result, and why Airflow swallowed the data without an error.Wed, 27 May 2026 00:00:00 GMThttps://frogwebp.com/log/streaming-vs-batch-aggregation/https://frogwebp.com/log/streaming-vs-batch-aggregation/When 'every 30 seconds' is the same as 'too late.'Tue, 26 May 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-tumble-windows-detection/https://frogwebp.com/log/phronis-tumble-windows-detection/Incremental materialized views that update as each event lands, not every 30 seconds.Mon, 25 May 2026 00:00:00 GMThttps://frogwebp.com/log/idempotency-data-pipelines/https://frogwebp.com/log/idempotency-data-pipelines/Why the same run twice should produce the same result once.Sun, 24 May 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-sdk-decorators/https://frogwebp.com/log/phronis-sdk-decorators/Instrument an agent in two decorators, with no framework lock-in.Sat, 23 May 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-star-schema-partitions/https://frogwebp.com/log/spectrum-star-schema-partitions/Building the warehouse layer: fact_events, four dimensions, and the index strategy.Fri, 22 May 2026 00:00:00 GMThttps://frogwebp.com/log/write-before-the-answers/https://frogwebp.com/log/write-before-the-answers/Documenting the process, not just the result: the conviction underneath all of it.Thu, 21 May 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-kill-switch/https://frogwebp.com/log/phronis-kill-switch/From alert to enforced stop, with state that survives a restart.Wed, 20 May 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-cross-tenant-retention/https://frogwebp.com/log/spectrum-cross-tenant-retention/A missing WHERE clause that leaked retention across accounts.Tue, 19 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-cleaning-multilingual-pdfs/https://frogwebp.com/log/contextflow-cleaning-multilingual-pdfs/Six transformations, in an order that matters, to make academic text searchable.Mon, 18 May 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-partition-ddl-visibility/https://frogwebp.com/log/spectrum-partition-ddl-visibility/A DDL-visibility bug, and why partition creation has to commit alone.Sun, 17 May 2026 00:00:00 GMThttps://frogwebp.com/log/spectrum-nulls-not-distinct/https://frogwebp.com/log/spectrum-nulls-not-distinct/Why dedup silently failed, and the Postgres 15 feature that fixed it.Sat, 16 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-chunking-with-provenance/https://frogwebp.com/log/contextflow-chunking-with-provenance/Splitting text so retrieval stays accurate and every result can cite its source.Fri, 15 May 2026 00:00:00 GMThttps://frogwebp.com/log/embeddings-explained/https://frogwebp.com/log/embeddings-explained/How words become vectors, and why distance in that space means meaning.Thu, 14 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-airflow-dag/https://frogwebp.com/log/contextflow-airflow-dag/Orchestration with the right retries per task, and chunks that don't go through XCom.Wed, 13 May 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-kubernetes-helm/https://frogwebp.com/log/phronis-kubernetes-helm/From an 11-container compose stack to 8 pods Running in under 3 minutes.Tue, 12 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-deterministic-chunk-ids/https://frogwebp.com/log/contextflow-deterministic-chunk-ids/Re-running the pipeline updates in place, never duplicates, because of how IDs are made.Mon, 11 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-local-embeddings/https://frogwebp.com/log/contextflow-local-embeddings/Why a small local model and L2 normalization are the right default for RAG.Sun, 10 May 2026 00:00:00 GMThttps://frogwebp.com/log/building-alone-in-public/https://frogwebp.com/log/building-alone-in-public/Deep work, scenius, and why solitude and an audience aren't opposites.Sat, 09 May 2026 00:00:00 GMThttps://frogwebp.com/log/phronis-iceberg-cold-storage/https://frogwebp.com/log/phronis-iceberg-cold-storage/Every agent event, in Parquet, queryable as of any point in the past.Fri, 08 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-sidebar-global-mutation/https://frogwebp.com/log/contextflow-sidebar-global-mutation/A Streamlit slider that quietly rewrote the app's settings singleton.Thu, 07 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-env-silently-ignored/https://frogwebp.com/log/contextflow-env-silently-ignored/Nested Pydantic settings classes each need to be told where to read.Wed, 06 May 2026 00:00:00 GMThttps://frogwebp.com/log/for-update-skip-locked-queue/https://frogwebp.com/log/for-update-skip-locked-queue/Turn any PostgreSQL table into a safe, concurrent work queue.Tue, 05 May 2026 00:00:00 GMThttps://frogwebp.com/log/contextflow-structlog-printf-trap/https://frogwebp.com/log/contextflow-structlog-printf-trap/Two logging APIs that look identical and behave completely differently.Mon, 04 May 2026 00:00:00 GMThttps://frogwebp.com/log/python-protocol-pattern/https://frogwebp.com/log/python-protocol-pattern/Python structural typing for clean, replaceable seams.Sun, 03 May 2026 00:00:00 GMThttps://frogwebp.com/log/rag-provenance/https://frogwebp.com/log/rag-provenance/Retrieval you can't cite is retrieval you can't trust.Sat, 02 May 2026 00:00:00 GMThttps://frogwebp.com/log/chunking-for-rag/https://frogwebp.com/log/chunking-for-rag/The most underrated knob in a retrieval pipeline.Fri, 01 May 2026 00:00:00 GMThttps://frogwebp.com/log/the-long-detour/https://frogwebp.com/log/the-long-detour/On restlessness, reading, and finding the work that finally fit.Thu, 30 Apr 2026 00:00:00 GMT