5 Vercel Configuration Mistakes That Will Cost You Time and Users

If you’re deploying on Vercel, you’re probably looking for speed and efficiency in your web development workflow. But even small misconfigurations can lead to performance issues, frustrating downtime, and ultimately, lost users. I've been there myself, and trust me, it's not fun to debug after a deployment goes wrong. In this article, I’ll walk you through five common configuration mistakes that can cost you time and users, and how to avoid them.

1. Ignoring Serverless Function Limits

What It Is:

Vercel’s serverless functions have execution limits (10 seconds for free tier, 60 seconds for pro). Ignoring these limits can lead to failed requests.

Pricing:

• Free tier: 100 GB-hours per month
• Pro tier: $20/month with higher limits

Best For:

Building lightweight APIs without the need for a dedicated server.

Limitations:

Not suitable for long-running processes, like heavy data processing.

Our Take:

We initially deployed a data-fetching function without checking the execution time. It crashed frequently, leading to a poor user experience. Always profile your functions before deployment.

2. Misconfiguring Caching Headers

What It Is:

Improper caching can lead to stale content being served to users, or worse, unnecessary load on your servers.

Pricing:

No direct cost, but can lead to increased usage charges if not configured properly.

Best For:

Static content that doesn’t change frequently.

Limitations:

Dynamic content may require more fine-tuned cache configurations.

Our Take:

We learned the hard way when a change to our homepage didn’t propagate due to aggressive caching. Make use of Vercel’s caching strategies to ensure that your users always see the latest content.

3. Overlooking Environment Variables

What It Is:

Environment variables are key for managing different configurations between development and production. Forgetting to set them can lead to broken features.

Pricing:

Free for the first 10 variables, $20/month for additional.

Best For:

Storing API keys, database URLs, and other sensitive information.

Limitations:

If not set correctly, your application may fail to run or expose sensitive information.

Our Take:

We accidentally pushed a version without the right API keys set, which caused our app to malfunction. Always double-check your environment variables post-deployment.

4. Not Using the Right Build Output Settings

What It Is:

Vercel has specific settings for how to handle different frameworks. Not configuring the output correctly can lead to build failures.

Pricing:

Included in all tiers.

Best For:

Projects using Next.js, React, or other supported frameworks.

Limitations:

Custom setups may require additional configuration.

Our Take:

We once had a Next.js app that failed to build because we didn’t set the output directory. Make sure you follow Vercel’s documentation for your framework.

5. Skipping on Analytics

What It Is:

Vercel provides built-in analytics to monitor performance. Not using them means missing out on critical insights.

Pricing:

Free for basic analytics, $20/month for advanced features.

Best For:

Understanding user interaction and performance bottlenecks.

Limitations:

Basic analytics may not provide enough detail for larger applications.

Our Take:

We didn't enable analytics for our early deployments and missed key insights on load times. Use Vercel’s analytics to optimize your app based on real user data.

Conclusion

Avoiding these common Vercel configuration mistakes can save you time, money, and the frustration of losing users. Start by checking your serverless function limits and caching headers, ensure your environment variables are set, configure your builds correctly, and leverage analytics to monitor your app's performance.

Start Here:

To get the most out of your Vercel deployment, take a moment to review your current configuration against this list. It could save you a lot of headaches down the line.