monorepo

advancedwidespread

A monorepo is a shared codebase where a company or team stores and manages the full source code of multiple separate programs in one place.

In plain terms

Imagine a company where every department keeps its papers in a separate building and a separate archive. A monorepo is the opposite: a single large, shared archive where every project gets its own shelf, but the same registry and the same policy apply to all.

In software development, code is kept in a so-called repository (short: repo), which records every change. In a monorepo, the website, mobile app, backend system, and shared building blocks all live in the same single repository.

The benefit of this is that things that belong together can be modified simultaneously. If a common building block changes, it can be fixed everywhere it is used in a single step, without having to coordinate between multiple repositories.

In the era of coding agents, this has become even more important: the agent can reach the code of the whole system in one place, which makes it easier to find connections. Of course, with a very large repository even the agent cannot take in everything at once; there too, it has to search and select.

How it works

The team creates a single repository where every project gets its own folder, for example one for the website, one for the mobile app, and one for shared elements.
Shared code is kept in one place, and projects reference it directly, so everyone uses the same version.
When someone makes a change, the modification is recorded as a single commit, even if it affects multiple projects. This ensures the code in the repository is always in a consistent state; however, when individual programs go live is independent of this.
Specialized build tools track which projects are affected by changes and recompile and retest only those, avoiding the need to run everything from scratch.
Rules specify which folder belongs to whom and who must approve changes, ensuring accountability is maintained even in shared spaces.

An everyday example

A webshop team keeps the customer-facing site, the mobile app, and the order management system in a single repository. When the VAT calculation changes, the developer or the coding agent rewrites the shared calculation part with a single modification, and the tests immediately show whether it works correctly in all three places.

Who is affected

developerYour daily work is fundamentally shaped by whether you work in a single shared repository or in many separate ones, as each requires different tools and workflows. → Code

entrepreneur, executiveThe layout of the code affects how quickly your team can make changes and how effectively you can involve coding agents in the work.

jobseeker, new graduateThe term frequently appears in job postings and interviews, so it is worth knowing what it means and what working methods it entails. → Work & HR

A common misconception

MythA monorepo means the entire software is one huge, inseparable program.

In realityA monorepo is only about the storage method: many independent, separately runnable and separately deployable programs can coexist in a shared repository.

Limits and risks

At large scale, traditional tools slow down, so a dedicated build and test system may be needed, requiring effort to set up and maintain.
A faulty change in the shared part can ruin multiple projects at once, so it is risky without thorough automated testing.
Access is harder to regulate finely: whoever can see the repository typically sees all the code, which can be a problem with external partners or sensitive parts.
It does not pay off for every team: with few, independent projects, separate repositories may be simpler.

Similar, but not the same

polirepo – In a polyrepo setup, each project gets its own repository, while in a monorepo everything is in a single shared repository.
monolit – A monolith is a single large program that runs as one unit, so it concerns software architecture, while a monorepo only concerns where the code is stored.
code repository – Code repository is the general term for any version-controlled code collection; monorepo is an organizational method where many projects share a single repository.

Related concepts

Broader

code repository, version control, software development

Narrower

–

On the edge

polirepo, Git, monolit, microservice, coding agent, workspace, builder system

A brief history

The practice is older than the name: major tech companies already kept their code in a single shared repository in the 2000s, but the term "monorepo" only became widespread in the mid-2010s. It gained wide recognition through a 2016 study by Google engineers, which described how the company stores about two billion lines of code in one place.

Where things stand

As of late 2026, the monorepo is a common approach from large tech companies to small teams, with mature tooling, but not the only one: many organizations still work with separate repositories. The spread of coding agents has given it new momentum because the agent can reach the entire system's code in one place.

Status: 2026 November

In the news

Appears in 2 Agent Age stories; the curve shows weekly occurrence in the news magazine.

OpenAI builds new Git backend Pando after Codex agents drive commit surgeNov 4, 2026 · Code
AI code review: Atlassian splits it between two agents, JetBrains proposes a three-tier reviewOct 12, 2026 · Code

Also known as

monorepo · mono-repo · mono repo · monorepo · monolithic repository · monolithic storage · unified code repository · shared code repository

Sources

Wikipedia: Monorepo

This entry was machine-edited and has undergone machine expert review; the “In the news” section updates automatically from Agent Age stories.