What Happened When a Developer Tried Angel Investing

How It Started

A former coworker left and started a startup. B2B SaaS. He was technically competent, had an MVP already built, and needed initial funding. "Can you put in 5 million won?"

My first reaction was "angel investing? Me? A regular salaried worker?" But looking into it, there's actually no legal minimum investment amount. 5 million won was a significant chunk of my savings, but it was an amount that wouldn't end my life if I lost it.

Invested in June 2025. Got 1.2% equity. (For that number to mean anything, the company would need to be worth several billion won.)

What I Checked Before Investing

Being a developer, I could at least do technical due diligence. I asked to see the codebase, and he actually showed it. Architecture was reasonable, and tech debt was at manageable levels. This is a judgment call a non-developer investor simply can't make.

But I later realized you can't just look at the tech. Market size, sales capability, burn rate, competitive landscape -- these weren't my area of expertise and were hard to evaluate. I asked questions about the business model, and my coworker's answers were brimming with confidence. "We'll hit 10 million won monthly revenue within six months." Confidence isn't evidence. I didn't know that at the time.

Six Months Later: Reality

Monthly revenue at the six-month mark was 2.3 million won. 23% of the target. 14 customer companies. The product was good, but sales weren't happening. That's when I learned that B2B products don't sell themselves just by being good.

Burn rate was 8 million won per month against 2.3 million in revenue -- they were eating through 5.7 million monthly. Total initial funding was 80 million, which meant they'd hit zero in about 14 months.

Got a message about opening an additional funding round. Was I in for more? Honestly, I was tempted. But having already committed 5 million, I decided the risk of adding more was too high. I said no.

The Developer-Investor Dilemma

Then came the ask to help with development. "Just a few hours on weekends." I helped at first. But it gradually expanded until I was spending entire weekend days on it.

I'd put money in, so I wanted the company to succeed -- which made it hard to say no. That was my mistake. Investment and labor are separate, but in small-scale angel investing, that boundary blurs. After three months I drew the line and said "I can't do this anymore," but the process made things a bit awkward between us.

(This is what happens when you invest in someone you know.)

One Year Later: Current Status

The company is still alive. They secured seed funding and extended their runway. Monthly revenue has climbed to 4.8 million. Still far from profitability, but the trajectory isn't bad.

Current value of my 5 million? Honestly, unknowable. Until the company IPOs or gets acquired, it's just a number on paper. Could be zero. Could be 50 million. That uncertainty is the essence of angel investing.

What I Learned

Angel investing should be done with truly spare cash. If losing 5 million keeps you up at night, don't do it. I could stomach it because losing that amount wouldn't affect my daily life.

Technical validation and business validation are separate things. As a developer, I could evaluate the tech, but I missed the market viability. Next time, I'll definitely get input from someone with business experience.

Investing in acquaintances carries relationship risk. Money issues can affect friendships. You need to assess whether the relationship can handle that before writing the check.

Would I do it again? Probably yes. But next time I won't invest based on tech alone.