Landed a $5,000/mo enterprise client in month 3. They almost destroyed our startup.

When we launched our B2B SaaS, we were bootstrapped and desperate for revenue. So when a massive 1,000-person enterprise reached out and offered us a $5,000/month contract in our third month, we felt like we had won the lottery.

But there was a catch: they would only sign if we built specific features for them. They needed a custom compliance module, a specific integration with their legacy database, and white-labeling. We agreed, thinking the money would fund the rest of our growth.

For the next six months, we essentially became their outsourced dev agency.

• We paused all marketing and sales.

• We ignored our smaller SMB customers (who started churning).

• We dedicated 90% of our engineering time to building features that only one company in the world cared about.

By month 9, our product was a bloated, convoluted mess. It was no longer usable for small businesses, but we didn't care—we had the enterprise money.

Then, they got acquired. The new parent company already had a vendor for our exact use case, and they canceled the contract.

Within 30 days, we lost our biggest client (80% of our revenue), and our SMB base had completely eroded because we had ignored them for half a year. We almost went bankrupt. I learned the hard way that taking "dumb money" too early can force you to build a product nobody else wants.

For founders who have landed a massive client early on: How do you take the money without letting them hijack your product roadmap?

Do you say no to custom features and risk losing the deal? Do you charge an exorbitant "custom development fee" to make it worth the distraction? Or do you just build a separate, private fork of the product for them?