10 Common Mistakes with Vercel Deployment and How to Avoid Them

Deploying an app on Vercel can feel like a breeze—until it doesn't. As indie hackers and solo founders, we often face critical deadlines and limited resources, making deployment mistakes even more painful. In 2026, Vercel has solidified its place as a go-to platform for front-end deployments, but it’s not without its quirks. Here, I’ll share the common pitfalls we've encountered when deploying on Vercel and how you can sidestep them.

1. Ignoring Environment Variables

What Happens?

A common mistake is neglecting to set up environment variables properly. This can lead to your app breaking in production while it works perfectly in development.

How to Avoid It

Make sure to configure your environment variables in the Vercel dashboard under the "Settings" tab for your project. Double-check that they match those in your local environment.

Our Take

We once missed a critical API key, and our production app was down for hours. Now, we have a checklist that includes verifying environment variables before every deployment.

2. Not Using the Correct Build Command

What Happens?

Using the wrong build command can lead to failed deployments or unexpected behavior.

How to Avoid It

Check your package.json file for the correct scripts. For most Next.js applications, it should be "build": "next build".

Our Take

In our early days, we mistakenly used the default build command for a different framework, causing a cascade of errors. Always double-check your build command in the Vercel settings.

3. Forgetting to Optimize Images

What Happens?

Large images can slow down your site and lead to deployment failures if your build size exceeds limits.

How to Avoid It

Use Vercel's built-in Image Optimization or tools like ImageMagick before deploying. Ensure your images are compressed and properly sized.

Our Take

We learned this the hard way when a single unoptimized image caused our build to fail. Now, we automate image optimization in our CI/CD pipeline.

4. Not Setting Up Custom Domains Properly

What Happens?

Misconfiguring custom domains can lead to accessibility issues.

How to Avoid It

Follow Vercel's documentation carefully to set up your custom domain. Make sure DNS settings are correct and that you’ve added your domain in the Vercel dashboard.

Our Take

The first time we set up a custom domain, we left out a CNAME record, causing our site to be unreachable for days. We now have a standard operating procedure for domain setups.

5. Overlooking Serverless Function Limits

What Happens?

Vercel has limits on serverless function execution time and memory usage. Exceeding these can lead to unexpected errors.

How to Avoid It

Review the documentation for the latest limits and optimize your functions accordingly. Use async calls where necessary to reduce execution time.

Our Take

We had a function that exceeded the memory limit during a busy launch day, crashing our app. Now, we monitor function performance closely.

6. Failing to Handle CORS Issues

What Happens?

Cross-Origin Resource Sharing (CORS) issues can prevent your app from accessing resources.

How to Avoid It

Set up appropriate CORS headers on your API responses. If you're using serverless functions, ensure these headers are included in your response.

Our Take

We once faced a CORS issue that took hours to troubleshoot. Now, we include CORS handling in our function architecture from the get-go.

7. Not Utilizing the Preview Deployment Feature

What Happens?

Deploying code directly to production without testing can lead to major issues.

How to Avoid It

Leverage Vercel's Preview Deployments to test changes before pushing them live. This feature allows you to see how changes will look in a production environment.

Our Take

We’ve saved ourselves from embarrassing bugs by using Preview Deployments. It’s become a non-negotiable step in our workflow.

8. Skipping on Monitoring and Analytics

What Happens?

Without monitoring, you might not know when things go wrong until it's too late.

How to Avoid It

Integrate monitoring tools like Sentry or LogRocket to keep an eye on errors and performance metrics.

Our Take

After a few silent failures, we invested in monitoring tools. The insight has been invaluable for proactive fixes.

9. Not Testing Locally

What Happens?

Assuming everything works in production without local testing can lead to surprises.

How to Avoid It

Run your app in a local environment that mimics production as closely as possible. Use tools like Docker if necessary.

Our Take

We learned this lesson after a deployment that broke our app due to a missing local dependency. Now, we always run a local test before deployment.

10. Ignoring Documentation Updates

What Happens?

Vercel frequently updates its platform, and ignoring these changes can lead to outdated practices.

How to Avoid It

Regularly check Vercel’s documentation and changelogs. Subscribe to their updates if possible.

Our Take

We missed an important update that changed how we handled serverless functions. Staying updated has since become a priority for our team.

Conclusion: Start Here

To avoid these common mistakes, set up a clear deployment checklist that includes all the steps we've outlined. Make sure to regularly update your knowledge of Vercel’s features and limits. If you're just starting with Vercel, focus on the basics and gradually adopt more advanced features as you become comfortable.

What We Actually Use

We rely on Vercel for deployment, but we also incorporate tools like Sentry for monitoring, ImageMagick for image optimization, and Postman for API testing. This combination has served us well in avoiding deployment headaches.