Scalability: Can it handle the load?

In the startup world, we dream of "hockey stick" growth. But growth is only good if your product and your team can handle it. This is scalability.

Technical vs. Business Scalability

• Technical Scalability: Can your servers handle 1 million users if you currently have 1,000?
• Business Scalability: Can your customer support team handle 1,000 tickets a day if they currently handle 10?

Useful Vocabulary

• Bottleneck: The slowest part of your system. "Our manual approval process is the current bottleneck for onboarding."
• Throughput: The amount of work a system can do in a specific time. "We need to increase our throughput to handle the holiday rush."
• Elasticity: The ability to scale up and down based on demand. "Cloud providers offer elasticity, so we only pay for what we use."
• Technical Debt: Choosing a fast, non-scalable solution now that will need to be fixed later. "We're taking on some tech debt to ship this MVP, but we'll need to refactor for scalability later."

"Do Things That Don't Scale"

This is a famous essay by Paul Graham. He argues that in the very beginning, founders should do manual work (like hand-writing thank you notes or manually onboarding every user) to learn.

• Example: "In the early days, Airbnb founders went to New York to take photos of apartments themselves. That didn't scale, but it was essential for their success."

Phrases to Use

• "Will this solution scale to 10k users?"
• "We've hit a bottleneck in our payment processing."
• "We need to automate this process to make it scalable."

The growth-versus-profitability trade-off

For years, investors rewarded startups for growing fast, even if they lost money. The logic was that market share, once captured, is hard to take back. But when interest rates rose in 2022 and 2023, funding became scarce, and investors shifted their focus toward the path to profitability.

The vocabulary reflects this shift:

• We're in growth mode : spending aggressively to capture market share.
• We're pivoting to profitability : cutting burn to reach break-even.
• Rule of 40 : a benchmark saying a healthy SaaS company's growth rate plus profit margin should equal at least 40.

Common mistakes

1. Using gross burn for runway. Runway uses net burn, because revenue offsets spending.
2. Choosing among two things. Use between for two options (between growth and profitability); among is for three or more.
3. Forgetting the verb extend. Say extend runway, not increase runway or make runway longer.

Practice

A startup has $900,000 in the bank. Its gross burn is $120,000 per month and its revenue is $45,000 per month.

1. What is the net burn?
2. What is the runway?

Answers:

1. Net burn = $120,000 minus $45,000 = $75,000 per month.
2. Runway = $900,000 / $75,000 = 12 months.

You now have the survival math. In the next lesson, you will learn the SaaS vocabulary that describes what a healthy business looks like once it finds its feet.