Building startups is humbling. No matter how experienced you are as an engineer, starting a company teaches you that technical excellence is necessary but not sufficient for success.

Over the past few years, I've built several products: Marmof (an AI writing assistant I eventually sold), GetCopy (an AI copywriting tool), SmartSellers (analytics for Ozon.ru sellers), and most recently Relaticle (an open-source CRM that's grown to 1,000+ GitHub stars and 2,000+ registered users). Each one taught me something different about building products that people actually want.

Here are the lessons I've learned, often the hard way.

1. Fall in Love with the Problem, Not Your Solution

One of my early products failed because I built something technically impressive that nobody wanted. I was proud of the architecture and the code, but I hadn't validated the problem.

The shift: I now spend time talking to potential users before writing code. Conversations, landing pages, and mockups first.

Validation checklist before building:

• Talked to potential users about their pain points
• Identified a specific, painful problem
• Found evidence that people are currently solving it (badly)
• Confirmed willingness to pay (or strong engagement signals)

If you can't check most of these boxes, keep talking to users.

2. Build for One User, Not One Million

As engineers, we're trained to build scalable systems. But in the early days of a startup, scalability is a distraction.

Wrong approach: Building a multi-tenant SaaS platform with enterprise features before you have a single paying customer.

Right approach: Build something that perfectly solves one specific person's problem. Then find 10 more people with the same problem.

Some early product decisions that worked well:

• Manually onboarding every user with a video call
• Doing customer support in shared Slack channels
• Implementing features during sales calls
• Writing custom scripts for individual customers

This approach doesn't scale, but it teaches you things you can't learn any other way.

3. Speed Trumps Perfection (But Don't Skip Quality)

There's a balance between shipping fast and building quality. Early on, I leaned too far toward perfectionism. Later, I over-corrected and shipped too quickly, creating technical debt that slowed everything down.

The framework I use now:

Ship fast for:

• User-facing features (iterate based on feedback)
• Experiments and MVPs
• Internal tools
• Marketing pages

Take your time for:

• Data models and database schema
• Authentication and security
• Payment processing
• Core business logic

Technical debt is like financial debt: some is good for growth, too much is suffocating. Be intentional about which shortcuts you take.

4. Technical Founder ≠ CTO

Just because you can build doesn't mean you should be the technical leader forever. As the company grows, you need different skills:

• Phase 1 (solo/small team): You're the technical founder. Write code, ship features, talk to users.
• Phase 2 (growing team): You're transitioning to architect and leader. Hire senior engineers, build processes.
• Phase 3 (scaling): You might need a dedicated CTO if your skills and interests lie elsewhere.

The question to ask: "Am I the best person to lead engineering at this stage, or should I focus on where I add the most value?"

5. Product-Market Fit Is a Feeling, Not a Metric

Everyone talks about PMF (Product-Market Fit), but nobody really explains what it feels like.

Before PMF:

• You're pushing to get users
• Growth is linear (when you push)
• Churn is high
• You're constantly pivoting features
• Users say it's "interesting" or "nice to have"

After PMF:

• Users are pulling you
• Growth becomes more organic
• People complain when features break
• You're saying "no" more than "yes"
• Users say they "can't live without it"

With Relaticle, I started seeing PMF signals when users began contributing to the GitHub repo without being asked and when feature requests became very specific rather than vague.

6. Choose Your Co-founders Carefully

The co-founder relationship is more important than:

• Your initial idea (which will change)
• Your technical stack (which will evolve)
• Your initial funding

Red flags I learned to pay attention to:

• Different commitment levels (full-time vs. side project)
• Misaligned visions for company growth
• Poor communication during stress
• Unwillingness to have difficult conversations

What works:

• Complementary skills (technical + business)
• Shared values and work ethic
• History of working together
• Equal commitment and sacrifice

7. Fundraising Is a Means, Not a Goal

The tech media glorifies fundraising. But fundraising is just one path, and often not the best one.

When to raise money:

• You have PMF and need to scale
• Capital gives you a defensible advantage
• You're in a winner-take-all market

When to bootstrap:

• You can reach profitability with revenue
• You value control and flexibility
• Your market doesn't require massive upfront investment

I've built products both ways. Bootstrapping is harder initially but gives you more freedom. Neither is right or wrong—choose based on your market and goals.

8. Build in Public

One of my better decisions was sharing the journey openly:

• Writing about technical challenges
• Being honest about what's working and what isn't
• Engaging with the developer community

Benefits:

• Attracts users who believe in your mission
• Builds a network of supporters
• Creates accountability
• Opens unexpected opportunities

This is part of why Relaticle has grown to 1,000+ stars—the open-source community responds to transparency and genuine engagement.

9. Take Care of Yourself

I burned out more than once building products. Both times, it set things back more than any business challenge.

Non-negotiables I've learned:

• Sleep 7-8 hours
• Exercise regularly
• Take at least one day off per week
• Maintain relationships outside of work

The paradox: Taking care of yourself feels like slowing down, but it helps you move faster and make better decisions.

10. Success Takes Longer Than You Think

Every overnight success is years in the making. This is the hardest lesson because it tests your patience and resilience.

The reality is that most products take several years to reach meaningful traction. Plan accordingly.

Final Thoughts

Building products as a technical founder is one of the most challenging and rewarding things you can do. Not everything I've built has worked out—GetCopy and SmartSellers taught me more through failure than success. But Marmof eventually found a buyer, and Relaticle is growing in ways I didn't expect.

The hard times will be harder than you expect. The good times will be better than you imagine. Both are temporary.

Keep building.

Building something new? I'd love to hear about it. Reach out on Twitter or LinkedIn.