---
issue: 106
title: "Backend: dual lockfiles (yarn.lock + package-lock.json) diverge"
severity: medium
domain: Dependencies
labels: [backend, ci-cd, dependencies]
status: open
created: 2026-05-30
source: Full Codebase Audit 2026-05-30
---

# Backend: dual lockfiles (yarn.lock + package-lock.json) diverge

**Severity:** medium
**Domain:** Dependencies
**Labels:** backend, ci-cd, dependencies

## Description

`backend/package.json:117` has both `yarn.lock` and `package-lock.json` in the repo, and they are not kept in sync. CI and production use npm; the `packageManager` field references yarn. The two lockfiles represent different resolved dependency trees, so local yarn installs and CI npm installs can diverge.

## Options

1. Standardize on npm + `package-lock.json` (matches CI/prod), delete `yarn.lock`, fix `Dockerfile.dev`.
2. Standardize on yarn (matches `packageManager` field), make CI use yarn.
3. Keep both but regenerate and pin.

## Recommendation

Pick one (npm matches prod/CI), delete the other lockfile, align Dockerfiles, and regenerate.

## Affected Files

- `backend/package.json`
- `backend/yarn.lock`
- `backend/package-lock.json`
- `backend/Dockerfile.dev`

## References

- [Full Codebase Audit 2026-05-30](../09%20-%20Audits/Full%20Codebase%20Audit%20-%202026-05-30.md) — DEC-55
