5 Common Mistakes When Using Vercel for Your First Deployment

Deploying your first project on Vercel can feel like a rite of passage for indie hackers and solo founders. But let’s be real: it’s easy to trip over some common pitfalls that can turn excitement into frustration. In our experience, we've made these mistakes ourselves, and we’ve seen plenty of others do the same. Here’s a rundown of five common deployment mistakes to avoid when using Vercel in 2026.

1. Ignoring Environment Variables

What Happens

It’s tempting to hard-code your API keys and secrets directly into your codebase, especially when you’re just getting started. But this is a rookie mistake that can lead to security vulnerabilities.

How to Fix It

Use Vercel’s environment variable feature to store sensitive information securely. You can set these up in the Vercel dashboard under your project settings.

Our Take

We learned this the hard way. After exposing our API keys in a public GitHub repository, we had to rotate them—all because we didn’t use environment variables.

2. Not Configuring the Build Settings

What Happens

Vercel automatically detects your framework, but it doesn't always guess correctly. If you're using a custom build setup, failing to specify build settings can lead to runtime errors.

How to Fix It

Make sure to specify the build command and output directory in the Vercel configuration settings. This ensures that Vercel knows how to build and serve your app correctly.

Our Take

We once had to troubleshoot for hours because Vercel defaulted to the wrong build command. It’s not a fun way to spend your time.

3. Overlooking Deployment Previews

What Happens

Many first-time users overlook the deployment preview feature, which allows you to see changes before they go live. This can lead to unexpected bugs making it into production.

How to Fix It

Always create a deployment preview for your pull requests. This gives you a chance to test changes in a live environment before merging them.

Our Take

We now rely heavily on deployment previews. They saved us from pushing broken features multiple times, which can be a nightmare for user experience.

4. Misunderstanding Serverless Functions Limits

What Happens

If you’re using Vercel’s serverless functions, it’s easy to overlook their limitations, such as execution time and cold starts. Ignoring these can lead to performance issues.

How to Fix It

Be aware that serverless functions have a maximum execution time of 10 seconds on the free tier. If your function needs more time, consider optimizing it or using a paid plan.

Our Take

We had a serverless function that exceeded the execution time limit, causing it to fail silently. Knowing the limitations upfront would have saved us a lot of headaches.

5. Forgetting to Set Up Custom Domains

What Happens

Many users stick with the default Vercel subdomain, which isn’t ideal for branding or SEO. This can limit your project’s visibility and professionalism.

How to Fix It

Set up a custom domain through Vercel’s dashboard. This process is straightforward, and Vercel provides clear instructions for managing DNS settings.

Our Take

We initially launched a project on a Vercel subdomain and regretted it later. Custom domains not only look better but also improve your credibility.

Conclusion: Start Here for a Smooth Deployment

To sum it up, deploying your first project on Vercel doesn’t have to be a rocky road. Avoiding these five common mistakes—overlooking environment variables, build settings, deployment previews, serverless function limits, and custom domains—will set you up for a smoother experience.

If you’re just starting, focus on these areas before hitting that deploy button. You’ll thank yourself later.