---
title: "Schema migrations without application downtime"
description: "How can you change a schema while old and new code coexist?"
status: "coming-soon"
language: "en"
canonical: "https://bulnik.dev/en/articles/topics/T39.10/"
topicId: "T39.10"
---

> Coming soon — this article is being prepared. Below are its question, intended outcome, and place in the story.

## The question

How can you change a schema while old and new code coexist?

## What we will work through

Change a schema while old and new code coexist.

## Before you begin

Previously covered: Foreign keys and entity relationships; A transaction for a business operation.

- [Foreign keys and entity relationships](/en/articles/topics/T39.03/)
- [A transaction for a business operation](/en/articles/topics/T39.06/)