event-store-design

Event Store Design

Skill Overview

Event Store Design is a comprehensive skill for designing and implementing the storage layer of an event sourcing system, covering architecture design, technology selection, pattern implementation, and performance optimization.

Use Cases

1. Building Event Sourcing Infrastructure

When you need to build an event sourcing system from scratch, this skill provides complete architectural guidance, including core concept understanding, component design, and technology selection recommendations, helping you establish a scalable event storage infrastructure.

2. Choosing Event Storage Technologies

Faced with multiple technology options such as EventStoreDB, PostgreSQL, Kafka, and DynamoDB, this skill offers detailed comparative analysis and recommends the most suitable storage solution based on your business needs, technology stack, and performance requirements.

3. Implementing a Custom Event Store

When existing solutions cannot meet specific needs, this skill provides complete implementation templates and best practices across various technology stacks such as PostgreSQL, Python, and DynamoDB, helping you build a custom event store that fits your business requirements.

Core Features

1. Event Store Architecture Design

Provides complete guidance for event store architecture design, including the event streaming storage model, global position indexing, version control mechanisms, and subscription patterns. Includes reusable SQL Schema design and architectural diagrams to help you understand the core components of an event store and how they interact.

2. Multi-Technology Stack Implementation Templates

Provides full code templates across multiple technology stacks, including PostgreSQL, Python (asyncpg), EventStoreDB, and DynamoDB. These cover key functionalities such as appending events, reading streams, global subscriptions, and optimistic concurrency control, and can be used directly in production environments.

3. Production-Grade Best Practices

Covers critical best practices for running an event store in production, including immutable event design, stream ID naming conventions, correlation ID tracing, event version evolution, idempotency handling, index optimization, and backpressure handling, helping you avoid common pitfalls.

Frequently Asked Questions

What is an event store, and how is it different from a traditional database?

An event store is a storage system specifically designed for the event sourcing pattern and differs fundamentally from traditional CRUD databases. Traditional databases store the current state of entities, whereas event stores store an append-only, immutable history of events. This means data is never modified or deleted—only new events are appended. Event stores support two query modes: reading by stream (retrieving all events for a specific aggregate) and reading globally (retrieving all events in chronological order). This design naturally enables capabilities such as audit trails, time travel, and event replay.

How do I choose the right event store technology?

Choosing an event store technology requires considering multiple factors: EventStoreDB is the most pure option—it is purpose-built for event sourcing and provides complete subscription and projection functionality; PostgreSQL is suitable for teams with an existing Postgres technology stack—it requires manual implementation but offers flexibility; Kafka fits high-throughput streaming scenarios but is not ideal for querying by stream; DynamoDB is suitable for AWS Serverless architectures but comes with query limitations; Marten is an excellent choice in the .NET ecosystem. It is recommended to prioritize EventStoreDB or PostgreSQL unless there are special technology stack constraints.

Which is better for event sourcing: EventStoreDB or PostgreSQL?

They each have their strengths and weaknesses. EventStoreDB is a database built specifically for event sourcing. It supports advanced features out of the box, such as stream subscriptions, projections, and competing consumers, with lower operational complexity—though it introduces new technical components. PostgreSQL is a general-purpose database—you need to implement the event store logic yourself, but you can reuse your existing database operational experience and infrastructure. If you are new to event sourcing or need fast delivery, EventStoreDB is recommended. If your team is very familiar with PostgreSQL and wants to reduce technology stack complexity, PostgreSQL is the more practical choice.