What Investors Check Before Writing a Check: Inside the Due Diligence Process

The due diligence process most founders never see starts the moment you send your deck. Before a single meeting, experienced investors have already checked your domain registration, your GitHub history, your LinkedIn profile against public records, and what comes up when they Google your name. Here is an inside account of exactly what they check and how they check it.

The Due Diligence Process Most Founders Never See

There are two phases of investor due diligence. The first is the visible phase: the meetings, the document requests, the customer reference calls. Founders know this phase is happening because investors explicitly ask for things. The second is the invisible phase: the independent research that happens before, during, and after those meetings, entirely without the founder's participation or awareness.

The invisible phase is where most deals quietly die. Not through a dramatic "we are passing because of X" conversation, but through a slow accumulation of credibility concerns that builds up in an investor's mind over several weeks. A LinkedIn title that does not quite match the company's public records. A GitHub repository that does not reflect the development history claimed in the deck. A reference call where the contact takes 30 seconds too long to answer a basic question about the founder's character.

Understanding both phases gives you the ability to manage both. The visible phase is manageable through preparation. The invisible phase is manageable through consistency — ensuring that every data point an investor might find independently tells the same story as your pitch deck.

Section 1: The First 30 Minutes

Within 30 minutes of receiving your pitch deck, a thorough investor will have done the following:

Read the deck with internal consistency in mind. They are not yet assessing whether the business is good — they are checking whether the story holds together. Does the customer count on the traction slide match the revenue divided by the stated ACV? Does the founding date on the cover match the founding date in the narrative? Are the market sizing numbers consistent with the revenue projections?

Searched the company name on Google. What comes up? Press coverage, product reviews, Trustpilot or G2 ratings, news about previous funding rounds, or news about problems. Any result that is surprising relative to the pitch deck narrative gets flagged for follow-up.

Checked the domain registration date via WHOIS. This takes 45 seconds and frequently surfaces discrepancies in founding timeline claims. A company that says "we have been building for 2 years" with a domain registered 6 months ago needs to have an explanation — a prior domain, a stealth period with a different name. Without an explanation, this is an immediate credibility gap.

Looked at the company's LinkedIn page. Employee count (LinkedIn shows a range), recent hires, who is listed as working there. Founders who are listed as employees on the LinkedIn page when the deck says they are co-founders creates a confusing signal. Employees listed on LinkedIn who do not appear on the team slide in the deck is also a flag — are they contractors? Have they already left?

Section 2: The Background Check

Founder background verification is one of the highest-value diligence activities because it is verifiable in ways that financial projections are not. Every job title, every employer, and every claimed achievement can be confirmed or contradicted through independent sources.

The process: search each founder's full name plus each employer they list. Cross-reference the job title they claim with any public records from that employer (news mentions, conference speaker listings, company blog posts, other employees' LinkedIn profiles from that period). Look for the founder mentioned in the context of that company at the time they claim to have worked there. Absence of any corroborating records for a significant role does not prove deception, but it raises a question that needs to be answered.

Prior companies the founders started are also researched. If a founder mentions a "successful exit" in their deck, the investor will look for the acquisition announcement, the acquiring company, and — ideally — confirmation that the founders personally received meaningful proceeds. Many "successful exits" at small companies involved employees being retained by acquirers with no significant financial upside to the founders. These are legitimate experiences but are very different from a $10M exit claim.

Public litigation history is also checked. A founder involved in a prior lawsuit — whether as plaintiff or defendant — is a material fact that should be disclosed proactively. Investor tools and public court records make this discoverable. A founder who discloses a prior legal dispute with full context ("I had a business dispute with a co-founder 5 years ago that was settled out of court; happy to discuss") is in a far better position than one whose investor discovers it independently.

Section 3: The OSINT Scan

OSINT — Open Source Intelligence — is the systematic collection and analysis of publicly available information. Sophisticated investors apply it routinely to every deal they seriously consider. Here is what it typically covers:

GitHub analysis: For technical startups, the GitHub organization reveals the true development history of the product. Date of first commit (which should roughly correspond to the founding date), number of contributors (a team of 3 engineers should show 3 contributing accounts), commit frequency over time (consistent commits signal active development; bursts followed by inactivity signal fundraising mode), and code quality signals from visible repository structures.

Domain and web archive: WHOIS lookup for domain registration date, registrant information, and renewal history. Wayback Machine review of the website over time: when did the site first appear? What did early versions look like? Were there significant changes that suggest a pivot or a rebrand that is not disclosed in the deck?

News and media search: Google News searches for the company name, product name, and founder names over time. Includes searching for the company in conjunction with terms like "lawsuit," "scam," "dispute," "fired," and similar risk-adjacent terms. This sounds aggressive, but it is standard practice for investors managing concentrated positions in illiquid assets.

Hiring signals: Job postings on LinkedIn, Indeed, and AngelList create a timeline of company growth and strategic priorities. A company claiming to have launched an enterprise product 18 months ago with no enterprise sales job postings until 3 months ago has a timeline inconsistency. Hiring data also helps verify current team size against deck claims.

Section 4: Market Validation

Independent market validation is how investors stress-test the TAM/SAM/SOM numbers in a pitch deck. The process involves researching the market from scratch using sources independent of the ones cited in the deck, then comparing the conclusions to the founders' claims.

Specifically, investors look for: independent research reports that confirm or contradict the market size figures cited. Industry association data for the sector. Public company filings from comparable companies that give real revenue data for similar markets. News coverage of the sector that either validates the "market timing" thesis or raises questions about it.

A startup claiming a $4B TAM that is contradicted by all independent research — where the actual market is closer to $400M — has a fundamental problem: either the founders do not understand their own market, or they are deliberately inflating the TAM to imply a larger return opportunity. Neither interpretation builds confidence. The best outcomes are when investor research confirms the founder's market analysis — this creates genuine alignment and removes a source of diligence friction.

Section 5: Traction Verification

Revenue and traction claims are verified, not taken at face value. The standard verification approach for early-stage companies:

Document request: Stripe dashboard screenshots or bank statements showing revenue. These are hard to fabricate convincingly and are the most direct evidence that revenue claims are real. Monthly MRR breakdown for the past 12-18 months. Customer contracts or agreement summaries showing actual contract values.

Customer reference calls: 2-3 customer calls minimum for serious diligence. The investors ask: how long have you been a customer? What do you pay? Would you renew? What is the primary value you get from the product? The answers to these questions are cross-referenced with the deck's claims. Significant discrepancies between what customers report and what the deck claims create immediate deal-level concerns.

Independent customer identification: In some cases, investors will identify customers independently — through LinkedIn searches of companies the startup has mentioned as customers, through press releases, or through the startup's public case studies — and reach out to those customers without using the founder-provided reference list. This process surfaces customer experiences that the founders' selected references might not reveal.

Section 6: The Reference Call

Reference calls are the final verification layer before a decision. Investors typically ask founders for 3-5 references — former colleagues, co-workers, previous investors, or early customers. They then conduct calls with those references and, importantly, also cold-call references they identified independently.

The questions investors really ask on reference calls — not the polite versions, but the ones that carry actual signal:

"If you were evaluating this company as an investor, what is the biggest risk you would worry about?" This question bypasses the instinct to be diplomatically positive and surfaces the reference's genuine concerns.

"Can you tell me about a specific time when this founder got something wrong, and how they responded?" This assesses coachability, honesty, and resilience — all of which matter more than any single success story.

"On a scale of 1-10, how strongly would you recommend investing in this founder? And what would make you give a 10?" The second part of this question is more important than the number — it reveals what the reference genuinely believes is missing or uncertain.

"If this company fails, what will have been the reason?" Asking people to articulate failure modes cuts through optimistic framing and surfaces the most honest view of the risk profile.