John Donboli

Writing › 2026-10-12 · by John Donboli

A First-Pass Due Diligence Checklist for Early-Stage Investors

A practical checklist covering team, product, finances, ownership, and legal basics to review before investing in an early-stage company.

Due diligence at the earliest stages looks different from the exhaustive reviews that happen in later rounds. There is rarely much data, and the goal is to catch avoidable problems and understand what you are actually buying. Here is a first-pass checklist I use to organise my thinking.

The team

The product and customers

The numbers

Ownership and the cap table

Legal basics

Risks in writing

Finally, write down the three most likely ways the investment could fail and how you would know early. If you cannot name them, you probably do not yet understand the business well enough to invest.

General information only. Not investment, legal, or tax advice, and not an offer or solicitation to buy or sell any security.


John Donboli is a San Diego business owner with a J.D. who is preparing to begin an MBA, and writes about business and early-stage investing. He is not currently licensed to practice law. More about John.