Nx vs Lerna: Which Monorepo Tool for CI?
Nx is a full monorepo build platform with caching and affected runs; Lerna focuses on versioning and publishing - and modern Lerna runs on Nx underneath.
Nx is a feature-rich monorepo system with a task graph, computation caching (local and remote), generators, and plugins. Lerna manages monorepo versioning and publishing; since the Nx team took it over, modern Lerna uses Nx for task running.
| Nx | Lerna | |
|---|---|---|
| Scope | Build platform (cache, plugins) | Versioning + publishing |
| Task/computation cache | Yes (local + remote) | Via Nx (modern Lerna) |
| Affected runs | Yes (nx affected) | Yes (via Nx) |
| Publishing | External / plugins | Core feature |
| Relationship | Powers modern Lerna | Built on Nx now |
In CI
For caching, the task graph, and affected-only runs, Nx is the engine - and modern Lerna already uses it under the hood. Lerna's distinct strength remains coordinated versioning and publishing. Many teams use Nx for fast CI tasks and Lerna for releases, or Nx alone with a separate publish step. They cooperate more than they compete now.
Speed it up
Enable Nx's remote cache across CI jobs and scope to affected projects - the biggest speedup. Tasks that still run on a cache miss execute on CI runners; faster managed runners shorten those.
The verdict
Want a full monorepo build platform with caching and affected runs: Nx. Need coordinated versioning and publishing: Lerna (which now runs on Nx). Many monorepos use Nx for tasks and Lerna for releases.