12 Technical Diligence Questions VCs Ask, and Why Founders Who Stumble Lose the Deal

What VCs Are Actually Auditing

Technical due diligence is not a code review. VCs are not trying to evaluate whether your Python is idiomatic or your React components are well-structured. They are trying to answer one question: how much execution risk does this codebase add to the deal?

At Sequoia, Bessemer, and most top-quartile Series A firms, technical diligence is handled by a third-party engineering firm (firms like Bain's tech practice or smaller specialists like SiriusPoint Technical Advisors) or by a venture partner with a CTO background. That person typically spends 2-3 hours interviewing your technical lead, reviewing your architecture, and writing a memo that lands on the partner's desk before the term sheet conversation.

What they're scoring:

• Scalability ceiling: Can the system handle 10x current load without a rewrite?
• Security posture: Are you one breach away from a regulatory fine or a customer exodus?
• Team bus factor: Does the platform fall over if one engineer quits?
• Dependency exposure: Are you one vendor outage away from a service disruption?
• Technical debt load: Is the debt manageable, or is it the kind that halts product velocity?

A bad score doesn't automatically kill the deal. But it reprices the risk. That shows up as a lower valuation, a smaller check, or deal conditions requiring specific infrastructure fixes before capital releases.

The 12 Questions VCs Will Ask

These are real questions from technical diligence calls. Some come from the third-party reviewer. Some come directly from the investing partner. All of them should have a clear, non-defensive answer ready before you take the first call.

Architecture and Scalability (Questions 1-4)

1. Walk me through your architecture from the user request to the database write.

This is the opening question 90% of the time. They want to see if you understand your own system. The right answer is a clear, step-by-step description: load balancer, application server, queue if applicable, database, any caching layer. If you're the founder and you stumble here, the call is already downhill.

2. What's your current peak load, and where does the architecture break first?

Name a real number. "We handle 12,000 concurrent sessions at monthly close when our fintech customers are running reports" is an excellent answer. "We're not sure, we haven't stress-tested it" is the answer that gets flagged in the memo.

3. How are you handling database scaling: read replicas, sharding, or are you still on a single Postgres instance?

Single instance is fine at $2M ARR. What they're looking for is whether you've thought about the path. Have a one-sentence plan: "We're on RDS Postgres single-instance today, and we've modeled that we'll need read replicas around 50,000 active users, we're at 8,000 now."

4. What does your deployment pipeline look like, and how long does a production deploy take?

CI/CD setup, test coverage percentage (give a real number, not "decent"), and time-to-deploy. If your answer is "we SSH into the server and run a script," that will appear in the memo. That's not necessarily a deal-killer at seed, but it will require explanation at Series A. See also how you're thinking about product roadmap build vs. buy tradeoffs, internal tooling falls under the same decision framework.

Security and Compliance (Questions 5-7)

5. What's your SOC 2 status?

Type I, Type II, in progress, or not started. Know which one. If you're not started and you're selling to enterprise customers, have a ready answer for when you'll be. Most Series A investors expect you to be at least in progress if you're above $3M ARR with any enterprise logos.

6. How do you handle customer data: encryption at rest, encryption in transit, and access controls?

The answer needs to be specific. "We use AWS with encryption enabled" is better than "we follow best practices." "AES-256 at rest via RDS encryption, TLS 1.2+ in transit, and we use role-based access with quarterly access reviews" is the answer that ends the security conversation quickly.

7. Have you had any security incidents or data breaches in the last 24 months?

Answer honestly. If yes, describe what happened, what you fixed, and what controls exist now. Founders who try to minimize or hide incidents get discovered anyway during diligence, and the concealment is worse than the incident.

Engineering Org and Process (Questions 8-10)

8. What's your bus factor?

Bus factor: the number of engineers who would need to leave (or "get hit by a bus") before the system becomes unmaintainable. If the answer is 1, that's a significant flag. Be honest, but follow up with what you're doing about it: documentation sprints, pair programming rotation, runbooks.

9. What does your on-call rotation look like, and what was your last major incident?

"We don't have formal on-call, the CTO handles it" is a common answer at seed. That's fine. At Series A, investors want to see you've started formalizing. Name your last production incident, how long it took to resolve (mean time to recovery, or MTTR), and what changed afterward.

10. How do you manage technical debt? Give me a concrete example of debt you know about and your plan for it.

This question is a trap for founders who either (a) claim they have no technical debt, which is immediately disqualifying because no codebase is debt-free, or (b) describe a mountain of debt with no plan. The winning answer: name one specific known piece of debt, its rough cost to fix, the risk it creates if unfixed, and the milestone at which you'll address it.

Data, Dependencies, and Vendor Risk (Questions 11-12)

11. What are your critical third-party dependencies, and what's your failover plan if one goes down?

List the stack: AWS, Stripe, Twilio, Segment, whichever. For each critical path dependency, explain what happens if it fails. "Stripe goes down and payments queue; we process them automatically when service restores" is a solid answer. "We haven't thought through that scenario" is the answer that ends up in the risk section of the memo.

12. How do you handle data backup and disaster recovery? What's your RTO and RPO?

Recovery Time Objective (how long to restore service) and Recovery Point Objective (how much data loss is acceptable). Know these numbers or know how to derive them from your backup policy. "We back up to S3 daily, RTO is about 4 hours, RPO is 24 hours" is honest and complete. Founders who have never heard these terms get flagged as operational risks even if the product is excellent.

How to Prepare Without a CTO

If you're a non-technical founder going into Series A diligence, you have three options: hire a fractional CTO for 30 days, prep your lead engineer to be the point person on all technical calls, or do a pre-diligence audit with a technical advisor.

Whichever path you choose, build these artifacts before the first call:

Architecture diagram. One page. Boxes and arrows. Every external dependency labeled. VCs use this to identify single points of failure in 10 minutes. If you don't have one, have your engineer draw it this week.

Known debt summary. A short document (even a Notion page is fine) that lists your 3-5 known technical debt items, their severity, and your plan. Investors respect founders who've catalogued their problems. It signals that you're running toward risk, not away from it.

Incident log. Even informal. Date, description, time-to-resolve, and the fix. If you've never had an incident, that's actually suspicious at scale, it usually means you haven't been tracking them.

Dependency map. A table of critical vendors, what you use them for, what the fallback is, and your monthly spend. This also feeds the financial diligence track.

What a Bad Technical Diligence Call Looks Like

The most common failure mode isn't an architectural disaster. It's a founder who gets defensive when the reviewer asks about a weakness.

Second most common: the technical lead and the founder give inconsistent answers on different calls. The reviewer compares notes. Inconsistencies about test coverage percentages, incident history, or current team size get flagged as integrity risks.

Third: founders who say "we'll fix that after the raise." Occasionally true. Usually interpreted as "we know it's broken and we're hoping you won't notice until after the wire." Investors have seen that movie. The better framing: "Here's what we've deprioritized and why, here's the cost to fix it, and here's the milestone that triggers the fix."

Self-awareness scores significantly better than perfection. A founder who can say "our test coverage is 34%, we know it, it slows down our deploys, and we're adding a test sprint in Q4" is more fundable than one who claims 90% coverage that the reviewer can verify is false.

The Infrastructure Signal VCs Use to Price Risk

Technical findings generally land in one of three buckets:

Clean enough. Minor debt, reasonable architecture for the stage, SOC 2 in progress, no critical single points of failure. This supports the full valuation. Most Series A companies land here.

Needs conditions. Material issues (no encryption at rest, single-engineer dependency on a core system, no DR plan) that don't kill the deal but become closing conditions. The term sheet says: capital releases in tranches as specific items are fixed. Founders who haven't prepared for this get surprised.

Deal risk. Architecture that cannot scale to the next order of magnitude without a rewrite, a history of security incidents that weren't disclosed, or a codebase with no documentation and one engineer who wrote 80% of it and just left. These reprice the deal significantly or kill it.

The difference between "needs conditions" and "deal risk" is usually preparation plus honesty. An issue that's been identified, documented, and planned for is a "needs conditions." The same issue discovered by the reviewer, when the founder claimed it didn't exist, becomes "deal risk."

The signal investors are reading is not just infrastructure quality. It's whether you run a company that knows what it has. That same signal applies to your investor reporting cadence, the founders who keep clean board materials tend to be the same founders who keep clean infrastructure docs. Investors pattern-match across both tracks.

Running the Rest of Your Investor Prep in Parallel

Technical diligence is one track in a fundraise. The narrative track (deck, GTM story, unit economics) runs simultaneously. Most founders under-resource both because the fundraise itself consumes 60-80% of founder bandwidth for 3-6 months.

The parts that tend to slip while fundraising: content marketing, social presence, and pipeline nurture. Investors look at your company's online presence during diligence, not because a LinkedIn post closes a deal, but because a dormant company with no public voice creates questions about GTM momentum.

If you're heading into a raise and you don't have the bandwidth to keep content moving, that's exactly the problem MorBizAI was built for. The engine drafts 1,400-1,800 word SEO posts in 90 seconds, cross-posts to LinkedIn, Bluesky, Threads, and Facebook in platform-native formats, and pulls keyword opportunities directly from Search Console so you're writing content that ranks, not content that gets 4 visitors a month.

The waitlist is live at morbiz.ai/marketing-engine. Worth joining before the raise starts, not after.

Back to the raise itself: understanding your CAC payback by sales model is typically the financial diligence question that lands right after the technical track closes. Get that answer ready at the same time.

The founders who come out of technical diligence strongest are the ones who treated it as a product problem: scope the audit, identify the gaps, build the documentation, practice the answers. Forty-five minutes of preparation per question is not excessive. It's the minimum to avoid losing a term sheet over something fixable.