How to Do Due Diligence on a Startup: The VC's Complete Framework

Why Due Diligence Matters More Than the Pitch

The pitch is theater. Due diligence is forensics.

A great pitch can get you excited about a company. DD tells you whether that excitement is justified. The best investors treat every diligence process with the same rigor regardless of how compelling the pitch was — because the better the pitch, the more important it is to stress-test it.

The framework below is what institutional VCs use. Adapt it based on stage: a pre-revenue seed-stage company doesn't have financial statements to analyze, but you can still do team DD, market DD, and product DD with full rigor. For Series A and later, every section applies.

Team Due Diligence

Team DD is where you start and often where you spend the most time at early stages. At seed, you're betting on people more than anything else.

Questions to answer:

Founder backgrounds: Where did each founder work before this? Run a real background check — verify employment history, check for public court records, search for any prior company affiliations. It's not paranoid; it's basic. Many funds use services like Checkr or Kroll.

Domain expertise: Do the founders have genuine insight into this problem, or did they discover it from the outside? The best founders have either lived the problem personally or have years of operator experience in the industry. Ask: "How did you come to work on this specific problem? What do you know about this space that most people don't?"

Founder-market fit: Is there a reason this team is more likely to win than another team attacking the same problem? Proprietary distribution, unique technical insight, domain network, regulatory expertise — look for the unfair advantage.

Co-founder dynamics: How long have they known each other? Have they worked together before? Ask founders separately about decision-making: "How do you and your co-founder handle major disagreements?" Inconsistent answers reveal something. Also check equity split — equal splits often signal the team hasn't had the hard conversation about who's actually leading.

References: Call at least 3 people who have worked closely with each founder — not the references they provide (those are screened), but references you find yourself through LinkedIn or mutual connections. Ask references: "What's this person's superpower? What's their biggest weakness? Would you work with them again? Do you think they can build a large company?"

Red flags in team DD:

• Founder who can't answer basic questions about their own industry
• Prior company that ended badly with no self-awareness about what went wrong
• References who give vague, lukewarm answers
• Unexplained employment gaps or company exits
• Co-founders who talk over each other or contradict each other's version of the story

Market Due Diligence

You can have the best team in the world, but if the market isn't there, it doesn't matter.

Questions to answer:

Market size — bottoms up: Don't accept the founder's TAM slide at face value. Build your own bottoms-up model. How many potential customers exist? What's the realistic ACV or ARPU? What penetration rate is achievable in 5-7 years? Do the math yourself.

Market timing: What's changed recently that makes this the right moment? Regulatory shifts, API availability, infrastructure cost drops, behavioral shifts (remote work, mobile-first consumers) — there should be a clear "why now" that you can independently verify.

Customer interviews: Talk to 5-10 potential or actual customers before you close. These conversations are the most valuable hour you can spend in diligence. Ask customers: "How are you solving this problem today? What would it take for you to change? How much are you spending on this problem?" If the founders gave you a warm intro to customers, also find cold customers through your own network.

Competitive landscape: Do your own competitive mapping. Research every direct and indirect competitor. Download competing products. Read reviews on G2, Capterra, Reddit, niche forums. Talk to customers of competitors. Understand why customers choose each option and what their switching triggers are.

Market structure: Is this a winner-take-all market or a fragmented market? Enterprise SaaS tends to be fragmented. Consumer social tends toward winner-take-all. Marketplace dynamics depend heavily on whether supply and demand are localized or global. Your investment thesis depends on understanding this.

Red flags in market DD:

• Market size that's only large when you're being generous with definitions
• "No real competition" — this either means no market or the founders don't understand their competitive landscape
• Customers who say the problem is real but "not a priority right now"
• Market heavily dependent on a single platform (App Store, Amazon) with no control

Product Due Diligence

Use the product. This sounds obvious; many investors skip it.

Questions to answer:

Core product experience: Sign up for the product. Use it. If it's B2B, ask for a demo sandbox account. Where does it delight? Where does it break? Does it solve the problem in the way the founders described?

Technical architecture: For software companies, have a technical advisor or your own engineering team do a code review or architecture review. Key questions: Is the codebase maintainable at scale? Are there obvious technical debt problems? Is there any proprietary technical moat, or is this built entirely on commodity libraries and APIs?

Build vs. buy decisions: What did they build, and why? What did they choose not to build? Founders who have built on top of very expensive third-party dependencies (e.g., a workflow automation company that processes everything through GPT-4 at $0.01 per call) may have a margin problem at scale that isn't visible at low volume.

Roadmap credibility: Ask for the product roadmap. Evaluate whether the team has the ability to execute it — does the roadmap reflect a clear-eyed understanding of what customers actually need, or is it a wish list? Have they shipped consistently against prior roadmaps?

IP ownership: Confirm that all intellectual property is owned by the company, not the founders personally. This means IP assignment agreements, work-for-hire clauses for contractors, and no code that was written on someone else's employer's time. Missing IP assignments are a deal-killer at Series A legal diligence.

Red flags in product DD:

• Product that looks great in a demo but falls apart in self-guided use
• Technical stack that makes scaling unnecessarily hard
• Key technical co-founder who has already transitioned to a non-technical role
• Roadmap that hasn't been updated in 6 months
• Missing IP assignments for key technology

Financial Due Diligence

At seed stage, financial DD is often light — there's not much history to analyze. At Series A and beyond, go deep.

Questions to answer:

Revenue quality: Is revenue recurring or transactional? What's the retention rate? Break revenue down by cohort and look at net dollar retention — are customers expanding, contracting, or churning?

Unit economics: Customer acquisition cost (by channel), LTV, payback period, gross margin by product line. If founders don't have this data, that's useful information in itself. Build a simple model from the underlying data and derive these yourself.

Burn rate and runway: Current monthly burn, current cash balance, implied runway. Does the business need to raise again within 12 months? Is the burn rate growing faster than revenue? A company burning $500K/month with $2M ARR has a very different profile than one burning $150K/month at the same revenue.

Cap table: Get the current cap table. Are there any unusual provisions — large SAFEs at low caps that will crush future round economics? Prior investors with super pro rata rights that will complicate a future lead? Employees with acceleration clauses that make the company hard to acquire? Any pending convertible instruments (SAFEs, notes) that haven't converted?

Customer concentration: What percentage of revenue comes from the top 3 customers? A company with 60% of revenue from one customer is not a SaaS business — it's a consulting engagement with a tech veneer. Concentration above 30% in the top customer is a significant risk.

Red flags in financial DD:

• Revenue that isn't actually recurring (large one-time implementation fees masquerading as ARR)
• Net dollar retention below 90%
• CAC payback period over 24 months without a clear path to improvement
• Large prior SAFE rounds at caps that will massively dilute founders at Series A
• Accounting records that are a mess or haven't been maintained properly

Legal Due Diligence

This is where surprises kill deals. Most legal DD issues are fixable, but they take time and money. Find them early.

Questions to answer:

Corporate structure: Is the company incorporated in Delaware as a C-corp? If not (Canadian corp, LLC, offshore structure), understand the implications and what it would take to restructure.

Founder agreements: Do all founders have signed IP assignment agreements, offer letters or founder agreements, vesting schedules, and non-competes (where enforceable)? If a founder left, was their departure handled cleanly?

Employee and contractor agreements: Do all employees have signed offer letters with IP assignment? Do all contractors have work-for-hire agreements? Any employee classification issues (contractors who should be employees)?

Intellectual property: Any pending or threatened IP claims? Any open source code incorporated in the product that might trigger license compliance issues (GPL, AGPL)? Any patents filed or pending?

Prior financing documents: Review all SAFE agreements, convertible notes, and any prior equity rounds. Understand all outstanding rights, preferences, and obligations.

Regulatory compliance: Depending on the industry: GDPR and CCPA compliance for consumer data, HIPAA compliance for healthcare data, SOC2 or ISO27001 for enterprise software, PCI compliance for payments. Ask specifically: have there been any regulatory inquiries or investigations?

Red flags in legal DD:

• Founder who refuses to provide full documentation
• Missing IP assignments (especially for offshore contractors)
• Prior investor with rights that weren't disclosed during pitch
• Open source license violations
• Any pending litigation

Customer Due Diligence

The single best diligence signal is talking to customers. Most VCs do this poorly — they rely on founder-provided references and call it done. Go deeper.

Questions to answer:

Reference calls: Talk to 5-8 customers. Ask: Why did you buy this? What problem does it solve for you? What would you lose if this product went away tomorrow? Have you considered alternatives, and why did you choose this? What's the one thing you wish the product did better?

Cold references: Find customers the founders didn't introduce you to. LinkedIn searches, conference attendees, industry forums. Cold references are dramatically more valuable than warm ones.

Churn analysis: If there are former customers, talk to them. "Why did you stop using the product?" is the most important question in all of customer DD. The answer reveals product limitations, pricing sensitivity, competitive dynamics, and customer segment fit.

Expansion signals: Are customers buying more over time? What's the expansion motion — seat expansion, usage-based growth, new product lines? Customers who say "we started with one team and now we're rolling it out company-wide" are telling you about net dollar retention before you've seen the data.

Red flags in customer DD:

• Customers who say the product is "nice to have" rather than critical
• Churn driven by switching to a competitor (vs. business failure or budget cuts)
• Customers who feel they were oversold and the product underdelivered
• No customer willing to be a public reference

Synthesizing Your Findings

After completing all six tracks of due diligence, you should be able to answer these questions:

1. Is this the right team to build this specific company in this specific market?
2. Is the market large enough to support a fund-returning outcome ($500M+ exit for a typical seed fund)?
3. Does the product work as advertised, and is there a path to a defensible technical or distribution moat?
4. Are the unit economics sustainable or on a credible path to sustainability?
5. Are there any legal or financial landmines that need to be cleaned up pre-close?
6. Do customers actually love this product, or is adoption driven by founder hustle and relationships?

You need a confident "yes" on questions 1, 2, and 6 to make an investment at seed. At Series A and beyond, all six need to be yes — or you need a compelling, explicit hypothesis for why a specific "no" is surmountable.

The deals you'll regret most aren't the ones you passed on. They're the ones you did without doing the work.