Event Store Design

Design and implement event stores for event-sourced systems.

A practical guide to designing and implementing event stores for event-sourced systems, where state is kept as an immutable append-only log rather than mutable CRUD rows. It compares EventStoreDB, PostgreSQL, Kafka and DynamoDB, then gives working schemas and implementations so you can pick the right backend and ship it correctly.

$15 one-time
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Prices include 20% VAT. · Forged on real agency work · one-time, no lock-in

  • Type Skill
  • Category Development
  • Delivery Email · instant
  • License One-time
Run preview
forgehouse, event-store-design

Inside the run · no black box

See the actual work before you buy it.

The skill designs the append-only backbone of an event-sourced system end to end. The exact build sequence:

  1. Picks the storage technology against a real comparison matrix: EventStoreDB for pure event sourcing, PostgreSQL when the stack already runs Postgres, Kafka for raw throughput, DynamoDB for serverless. Each comes with its known limitation written down.
  2. Lays out the schema: an events table with stream_id, event_type, JSONB payload, per-stream version and a global_position BIGSERIAL, locked by a UNIQUE(stream_id, version) constraint. UPDATE and DELETE on events are forbidden, only INSERT.
  3. Implements append with optimistic concurrency: every write passes an expected_version, a mismatch raises ConcurrencyError inside the transaction and the client retries with fresh state. Duplicate writes are neutralized by unique event IDs (idempotent write).
  4. Provides two read paths: read_stream for rebuilding one aggregate (stream_id plus from_version) and read_all over global_position for cross-stream consumers.
  5. Runs subscriptions on checkpoints: each consumer stores its last processed global_position, so a restarted projection resumes exactly where it stopped instead of replaying the world.
  6. Adds a snapshot strategy for long streams: persist aggregate state every N events (around 100), load snapshot first, replay only the tail. Stream IDs follow the AggregateType-uuid convention so category-level reads stay possible.
Use cases · what happens when you plug it in

One power source. 6 lines out.

event-store-design · core

core active · 6 lines

  1. Standing up a PostgreSQL event store with append-only events, snapshots and checkpoints

    ✓ standing up a postgresql
  2. Choosing between EventStoreDB, PostgreSQL, Kafka and DynamoDB for your stack

    ✓ choosing between eventst…
  3. Implementing optimistic concurrency control to prevent concurrent-write corruption

    ✓ implementing optimistic…
  4. Adding snapshots so long streams don't replay from event zero every time

    ✓ adding snapshots so long
  5. Building subscriptions that resume from the last processed global position

    ✓ building subscriptions t…
  6. Ensuring idempotent writes that safely ignore duplicate events on retry

    ✓ ensuring idempotent writes
Benefits · what you walk away with

Yours to keep.

Drag time forward. Watch what stays.

Forever

That's what owning means.

The rented stack

ai writing tool: subscription

expired · access lost

analytics suite: subscription

expired · access lost

design platform: subscription

expired · access lost

(nothing left)

Your forge

  1. Get a complete audit trail and natural undo/redo by treating events as immutable facts

    license: perpetual
  2. Prevent data corruption under concurrent load with version-based optimistic concurrency

    license: perpetual
  3. Keep read performance high as streams grow by replaying from snapshots instead of the start

    license: perpetual
  4. Pick the right event store technology with eyes open to each one's real limitations

    license: perpetual

subscriptions expire · deeds don't

What's included · the full manifest

Everything in the box.

Pick a piece up. Watch it work.

PostgreSQL schema with events, snapshots and subscription_checkpoints tables plus indexes

part 01 of 06 · in the box

6 parts · one working system · ships instantly by email

Who it's for

This wasn't forged for everyone.

  • Not for you if you'd rather rent a tool than own one.
  • Not for you if you want someone else to run your stack.
  • Not for you if you're happy guessing.
Still here? Good.

Backend architects and engineers building CQRS or event-sourced systems who need an event store that scales without sacrificing consistency or auditability.

then this was forged for you.

Works with

Universal by design: these run in any AI. Delivered in the open Agent Skills + MCP format (native in Claude); ChatGPT, Gemini, Cursor and Copilot adapt the same files their own way.

  • Claude Native format
  • ChatGPT Adapts via open standards
  • Gemini Adapts via open standards
  • Cursor Adapts via open standards
  • Copilot Adapts via open standards
Questions · still in the air

Catch what's on your mind.

the air is clear. nothing between you and the forge.
catch a spark: the forge will answer

  1. Can I run this on plain PostgreSQL or do I need a dedicated event database?

    Plain PostgreSQL works, and you get a concrete append-only schema with snapshots and checkpoints for it. EventStoreDB, Kafka and DynamoDB are compared so you pick a dedicated store only if your scale demands it.

  2. Isn't event sourcing overkill compared to normal CRUD?

    For plenty of apps it is, and the guide is honest about that rather than pushing it everywhere. It helps you judge when an immutable log actually pays off, like audit-heavy or concurrency-sensitive domains.

  3. Does it cover the full CQRS read side and projections?

    It focuses on the event store itself, the write log, concurrency control and snapshots. Building read models and projections on top is a neighboring concern it sets you up for but does not fully implement.

  4. How is it delivered?

    By email right after purchase: ready to run, downloaded instantly, no setup wait.

  5. One-time or subscription?

    A one-time purchase; no subscription or hidden fees. VAT (20%) is included.

  6. Can I get a refund?

    As a digital product, it can’t be refunded once downloaded. That’s why we show exactly what’s inside and who it’s for, right here.