Blog · Tag

#engineering

21 posts tagged with this.

  1. JUN 2026

    Operations · · 4 min

    RedDB on a Raspberry Pi: the smallest sane install

    A weekend exercise — image a Pi 5, install RedDB, load a hundred thousand rows, and see what happens when document + vector + KV + blob all live on a $80 board under the desk.

  2. MAY 2026

    Agents · · 8 min

    Agent SDK on RedDB: building custom agents with native persistence

    A walk through the four surfaces of a small Agent SDK — tool registry, memory adapter, conversation log, eval hooks — backed by RedDB instead of a stack of services. Ends with a working code-review bot in under 300 lines that remembers what it has reviewed, per repository.

  3. Engineering · · 11 min

    Chunking inside the engine: when the DB owns segmentation

    Most RAG stacks chunk in Python glue between Postgres and a vector store. The result is a second pipeline that drifts. This post walks through what it looks like when chunking is a declarative rule attached to a column, reranking is a query operator, and the engine — not the application — owns segmentation.

  4. Engineering · · 8 min

    Hybrid search done right: lexical, vector, and filter in one plan

    A walk through the RedDB query planner fusing BM25, vector similarity, and a structured filter into a single execution plan — with EXPLAIN output, the cost model behind it, and what happens on the edge cases that trip up naive two-stage rerankers.

  5. Engineering · · 14 min

    One WAL, four data models: how cross-modality transactions actually work

    A deep dive into the shared write-ahead log that lets a document update, a vector insert, a KV write, and a blob commit land in the same transaction. Record layout, the fsync contention tradeoff, and the four mitigations we shipped before the tail latency became someone else's incident.

  6. Migration · · 9 min

    Postgres + pgvector → RedDB: a migration playbook with wall-clock numbers

    A step-by-step playbook for moving a production Postgres + pgvector workload to RedDB — dual-write, embedding backfill, query translation, cutover, rollback — with measured timings from a 12M-row test corpus and the three places teams trip over.

  7. Engineering · · 1 min

    Hello from inside the engine

    A first note on what we're building and why a multi-model engine matters in 2026.

  8. Engineering · · 10 min

    Stop stitching Postgres, pgvector, S3, and Redis

    Every modern app you ship is four databases in a trenchcoat. Here is the bill — in failure surfaces, ops playbooks, and consistency models — that nobody costs out before signing.

  9. Engineering · · 7 min

    The tradeoffs we made to fit four engines in one

    Document, vector, KV and blob in the same transaction is not free. Here's the per-modality tuning surface we cut, the plugin story we sacrificed, and the cold-blob latency tail we accepted.

  10. RAG · · 8 min

    RAG without a second database

    When your vectors live on the same row as the document they describe, the entire CDC-and-backfill layer of a RAG pipeline disappears — and a class of stale-retrieval bugs goes with it.

  11. Field reports · · 7 min

    Notes from compaction hell

    Three months of LSM compaction tuning at production scale — the latency tail we measured, the four configuration changes that actually moved P99, and the one we wish we'd made on day one.

  12. Migration · · 9 min

    When NOT to migrate: a checklist

    The companion piece to every migration post. A decision tree for staying on your current stack — team size, pain quantification, runway — so you do not pay migration tax for a problem you did not have.

  13. Field reports · · 6 min

    Snapshot isolation, in practice

    What snapshot isolation gives you, what it doesn't, the write-skew anomaly that still bites, and the one application pattern that fixes most real cases.

  14. APR 2026

    Migration · · 6 min

    MongoDB → RedDB: the queries that change shape

    Idiomatic translations from MongoDB to RedDB for the patterns that actually appear in production code — aggregation pipelines, change streams, GridFS, and the three places where the literal translation is wrong.

  15. Operations · · 9 min

    Disaster recovery for RedDB: PITR, snapshots, regional failover

    An operator playbook for RedDB disaster recovery — point-in-time restore with example commands, snapshot scheduling, cross-region replication topology, the RPO/RTO numbers you can actually hit, and an honest list of what we don't yet do.

  16. Migration · · 8 min

    Out of Firebase, into a real backend

    A migration playbook for teams that outgrew Firebase — auth bridge, Firestore doc model, security rules, real-time — and an honest look at what you lose when the magic console goes away.

  17. RAG · · 6 min

    The drift window: why your RAG retrieves stale chunks

    A customer-visible failure mode unique to two-store RAG — source updates, queue lag, retrievals against the old embedding. Anatomy of one outage and how same-transaction writes eliminate the window.

  18. RAG · · 7 min

    Building an agent memory layer on RedDB

    A copy-pasteable schema for episodic, semantic, and procedural memory in a single database — with the queries that retrieve them and the bookkeeping that keeps them honest.

  19. Operations · · 7 min

    Self-hosting RedDB: the real-world checklist

    An operator-grade checklist for running RedDB on your own infrastructure — container images, k8s manifests, volume sizing, monitoring, backups, network policies, and the secrets-management decisions that bite later.

  20. Engineering · · 9 min

    Why 'best of breed' loses at small scale

    The ops cost of running four engines instead of one, measured in person-hours at team sizes of 2, 5, and 15 engineers. Multi-model isn't only a scale concern — it's a small-team unlock.

  21. Engineering · · 9 min

    When you don't need RedDB

    An honest list of workloads where Postgres + pgvector, SQLite, or a single-purpose store will serve you better than RedDB. If your shape is on this list, save yourself the migration.

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