# 6 Common Mistakes Founders Make During Technical Due Diligence

> Avoid the most costly technical due diligence mistakes founders make before funding rounds. Covers documentation, debt disclosure, team prep, and repo hygiene errors.

- **Published:** 2025-03-09
- **Author:** Clixo
- **Reading time:** 5 min read
- **Tags:** technical-due-diligence, startups, founders, codebase-audit
- **Canonical URL:** https://clixo.sh/blog/common-mistakes-founders-technical-due-diligence

Most founders go through technical due diligence exactly once before they understand what it actually involves. By then, the damage is already done — a deal has been repriced, a closing has been delayed, or worse, an investor has lost confidence in the team's judgment. These mistakes are not rare edge cases. They are patterns that show up reliably across companies of all stages and stack types.

Here are the six most common mistakes, and what to do instead.

## Mistake 1: Treating It Like a Surprise Inspection

The most common framing founders bring to technical due diligence is defensive: hide the problems, polish the surface, and hope the reviewer does not dig too deep. This is the wrong model entirely.

A good technical reviewer has run dozens of these engagements. They are experienced at finding the difference between a codebase that is genuinely clean and one that has been hastily staged. More importantly, investors understand that every company of any meaningful age has technical debt. What they are evaluating is not whether debt exists, but whether the team has it under control and understands its implications.

**What to do instead**: Run an internal audit before the formal process begins. Document what you find, triage it by severity, and bring that documentation to the review proactively. A founder who walks in with a prepared technical debt register immediately signals maturity.

```mermaid
flowchart TD
  A["2+ months before fundraise"] --> B["Internal codebase audit"]
  B --> C["Secrets scan with gitleaks"]
  C --> D["Update architecture docs"]
  D --> E["Build technical debt register"]
  E --> F["Brief engineering team"]
  F --> G["Formal DD review"]
  G --> H["Investor confidence"]
```

## Mistake 2: Underpreparing Your Engineers

Technical due diligence almost always includes conversations with your engineering team, not just a code review. Reviewers ask engineering leads directly about architecture decisions, deployment practices, incident history, and how new engineers ramp up. Founders often brief their engineers minimally and assume the code will speak for itself.

**What to do instead**: Prepare your senior engineers for the conversations they will have. Not by scripting answers — reviewers see through that quickly — but by ensuring everyone understands the context, the purpose of the review, and the kinds of questions they will be asked. An engineer who can articulate why a decision was made, including its trade-offs, is a stronger signal than one who gives polished but shallow answers.

## Mistake 3: Letting Secrets Sit in Version Control

Committed credentials, API keys, and database passwords in version control history are one of the fastest ways to turn a clean review into a serious concern. This is not a hypothetical risk: once a secret is in git history, it is there forever unless you deliberately scrub it — and even after scrubbing, the exposure window matters.

**What to do instead**: Run a secrets scan against your entire repository history before the review begins. Tools like `gitleaks` or `truffleHog` can do this in minutes. Rotate any credentials that appear in the results. Document that you did this and when.

## Mistake 4: Conflating "Working" with "Auditable"

A system that works in production is not the same as a system that a technical reviewer can assess with confidence. Reviewers need to understand the system, not just observe that it functions. Missing documentation, no architecture diagrams, opaque service boundaries, and undescribed deployment processes make it difficult for a reviewer to reach a confident conclusion — and an uncertain reviewer is more conservative, not less.

**What to do instead**: Before the review, write or update the core documentation: a high-level architecture diagram, service-level READMEs, and a description of how the system handles its most critical operations. This does not have to be exhaustive; it needs to be accurate and navigable.

## Mistake 5: Disclosing Technical Debt Only When Asked

Some founders disclose material technical debt only when a reviewer specifically asks about it. This feels like risk management but works against you. When a reviewer uncovers something you did not volunteer, it raises a question that has nothing to do with the technical finding itself: what else is the team not disclosing?

**What to do instead**: Put known technical debt in the data room from the start. A categorized register with honest effort estimates demonstrates that you understand your own system and have a plan for it. It also sets the frame for the conversation — the reviewer is evaluating your plan, not discovering a problem.

## Mistake 6: Waiting Until the LOI Is Signed

The most expensive version of technical due diligence readiness is the reactive one — scrambling to prepare documentation, clean up the codebase, and brief the team after a letter of intent has already been signed and a closing timeline has been set. Fixing significant problems under deadline pressure while continuing to run a company is genuinely difficult, and it shows.

**What to do instead**: Begin readiness preparation at least two months before you expect to start a fundraise or sale process. The minimum preparation is an internal audit, a documentation pass, and a secrets scan. The more you do before the formal process begins, the more control you have over the narrative and the timeline.

## The Common Thread

Each of these mistakes comes down to the same underlying problem: treating technical due diligence as an obstacle rather than as a structured conversation about risk. Investors who ask for technical review are not looking for a reason to walk away — they are looking for confidence that the team understands its system and can be trusted to execute. That confidence is built by demonstrating knowledge and transparency, not by minimizing exposure.

If you want an independent read on where your codebase stands before a formal review begins, [Clixo](https://clixo.sh/#contact) runs pre-DD readiness assessments that give you a structured picture of what a reviewer will find and what to address first.

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