Raising Your Series A/B/C What Engineering Leaders Need to Know

Technical due diligence exists at every funding stage, but what investors look for changes dramatically as companies grow. The scrutiny at Series A is different from Series C, and engineering leaders who understand these differences can prepare more effectively. Here's what I've learned from both sides of the table.

Series A: Can You Build?

At Series A, you're usually a small team with a working product and early traction. Investors are betting on your ability to scale what you've built. Their technical questions focus on fundamentals.

What they're looking for:

Team quality matters most. Who are your engineers? Where have they worked before? Can the current team scale the product, or will you need to upgrade as you grow? Investors want evidence that technical talent can attract more technical talent.

Architecture questions are directional, not detailed. Can your system scale to 10x current load? 100x? Investors aren't expecting perfect architecture from a seed-stage company, but they want to see that you've thought about growth paths.

Technical debt is expected and forgivable at this stage. What matters is whether you know where it is and have reasonable plans to address it. A CTO who understands the tradeoffs made to ship quickly is more valuable than one who insists everything is perfect. Knowing the red flags that evaluators look for helps you prepare proactively.

How to prepare:

Document your architecture. Even simple diagrams showing major components, data flows, and external dependencies demonstrate organization. Have a clear story about technology choices: why you picked what you picked and what you'd do differently.

Know your scaling story. Where are the bottlenecks? What breaks first under load? What's your plan when that happens? You don't need to have built it yet, but you need to have thought about it.

Be honest about technical debt. Pretending it doesn't exist raises red flags. Acknowledging it and showing you're making deliberate choices builds credibility.

Series B: Can You Scale?

Series B typically comes after you've found product-market fit and need to scale rapidly. The technical questions get more rigorous because the stakes are higher.

What they're looking for:

Evidence of operational maturity. How do you deploy? How do you monitor? What happens when things break? Investors want to see that you can operate at scale without everything depending on hero engineers. DORA metrics provide a framework for demonstrating this maturity.

Security and compliance become real concerns. Depending on your market, SOC 2, HIPAA, or other certifications might be expected. At minimum, you should have basic security hygiene: proper authentication, encrypted data, access controls.

Team structure and processes matter now. Can you hire and onboard engineers efficiently? Do you have engineering management in place? How do you make technical decisions? The days of the founding team doing everything are over.

How to prepare:

Invest in infrastructure before you need it. Monitoring, alerting, deployment automation. These things don't directly build product, but they're what separates teams that can scale from teams that collapse under growth.

Start security and compliance work early. These take longer than expected, especially if you're retrofitting. Beginning the SOC 2 journey months before you need it is better than scrambling during a deal.

Document your engineering organization. Org chart, hiring plan, promotion criteria, technical decision-making processes. Investors want to see that you've built a machine for scaling, not just a collection of talented individuals.

Series C and Beyond: Can You Endure?

Later-stage rounds involve more scrutiny because more money is at stake. Investors are evaluating whether your technical foundation can support a large, durable business.

What they're looking for:

Sustained execution. Your track record over years matters. How has the team grown? How has the architecture evolved? Do you hit your technical milestones? History becomes evidence of future performance.

Defensibility questions emerge. What's your technical moat? Is your technology truly differentiated, or could a well-funded competitor replicate it? The story about why your engineering advantage persists becomes important.

IPO-readiness indicators for later rounds. Financial controls, audit trails, disaster recovery, business continuity. The boring infrastructure required for public company life should be in place or clearly planned.

How to prepare:

Maintain documentation continuously. Don't scramble before fundraising. Keep architecture docs, security policies, and compliance certifications current. This is easier if it's ongoing than if it's a project.

Build relationships with technical due diligence firms. At later stages, investors often bring in specialists. Knowing what they look for and having done a self-assessment helps avoid surprises.

Plan for life after the raise. Part of Series C evaluation is how you'll use the capital. Having specific technical initiatives with clear ROI tells a better story than generic plans to "invest in engineering."

Common Mistakes at Every Stage

Some patterns cause problems regardless of stage:

Underselling or overselling. Some technical leaders downplay their work out of modesty. Others hype capabilities beyond reality. Both create problems. Investors compare what you say to what they find. Accuracy builds trust.

Not involving engineering leadership. Fundraising is often founder-led, but engineering leaders should be part of technical conversations. A CTO who can't explain their architecture or seems surprised by their own systems raises concerns.

Ignoring technical due diligence until it happens. The best preparation is continuous improvement. Companies that are always investor-ready have lower fundraising overhead than those that scramble before every round.

Treating diligence as adversarial. Investors doing due diligence are potential partners trying to understand your business. Approaching it collaboratively, proactively sharing information, and being responsive to questions creates better outcomes than defensive postures.

The Engineering Leader's Role in Fundraising

Fundraising isn't just the CEO's job. Engineering leaders should be prepared to tell the technical story, answer detailed questions about architecture and process, anticipate concerns and address them proactively, and represent the engineering team's capabilities convincingly.

The narrative matters. Investors hear dozens of pitches. The CTO who can clearly articulate why their technical approach creates competitive advantage, what risks they've managed and how, and what the team will build with the new capital stands out from those who just answer questions.

Preparation is the differentiator. The companies that raise successfully aren't always the ones with the best technology. They're the ones who can demonstrate they've built something real, understand its limitations, and have credible plans for what comes next.

Frequently Asked Questions

When should we start SOC 2 compliance?

Begin 6-9 months before you expect to need it, typically during or just after Series A. The process takes longer than expected, especially when retrofitting existing systems. Starting early prevents scrambling during Series B due diligence when it often becomes a requirement.

How involved should the CTO be in fundraising?

Heavily involved in technical conversations. A CTO who can't explain architecture decisions or seems surprised by their own systems raises concerns. Engineering leaders should be prepared to articulate the technical story, answer detailed questions, and represent team capabilities convincingly.

What technical metrics do investors want to see?

It varies by stage. Series A: architecture diagrams and scaling story. Series B: deployment frequency, incident response times, test coverage trends. Series C: DORA metrics, security audit results, and sustained execution track record over years.