Dear Railway Support Team,

I hope this email finds you well. I am a developer using Railway for my project.

I encountered an issue with build caching that took considerable time to resolve, and I would like to request detailed information about the cache specifications.

#### Problem Description

1. Project Overview: Real estate business efficiency tool using Next.js 14 + TypeScript + Prisma

2. Issue: After implementing new dashboard components, builds succeeded on GitHub Actions but the latest code was not reflected on Railway

3. Actions Taken:

- Multiple deployments executed (file changes were definitely occurring)

- Executed railway redeploy --yes

- Executed railway up --detach

- Attempted environment variable control

4. Final Resolution: Resolved through file change trigger (adding .railway-clear-cache file)

#### Specific Commit History

```

193a602 fix: 新しいダッシュボードの復元 (2 files changed, 98 insertions(+), 6 deletions(-))

300c8d1 fix: Prismaスキーマの修正 (2 files changed, 2 insertions(+), 2 deletions(-))

8046484 fix: 古いダッシュボードファイルを削除

```

#### Questions

1. Build Cache Specifications

- Under what conditions is cache used?

- Which layer caches (Docker Layer Cache, Next.js Build Cache, etc.) can cause issues?

- What are the conditions where cache is used even when files are changed?

2. Cache Clear Methods

- What is the officially recommended method for clearing cache?

- Is there a way to control cache through environment variables?

- What are the conditions for automatic cache invalidation?

3. Future Prevention

- Are there methods to prevent similar issues?

- Is there a way to check cache status during deployment?

#### Expected Response

- Detailed specifications of build caching

- Officially recommended cache clearing methods

- Prevention strategies for similar issues

I would greatly appreciate your response when you have time.

Thank you for your time and consideration.

Best regards,