Technical Due Diligence Checklist for Fractional CTOs and Founders

Investor technical due diligence feels like an exam with no syllabus until you have been through it a few times. Whether you are preparing your company for a Series A or a fractional CTO is assessing a potential client, a systematic checklist prevents the most common oversights and keeps the process from becoming a six-week distraction for the engineering team.

What Technical Due Diligence Actually Covers

Technical due diligence is not just a code review. It is an assessment of the entire technical foundation of the business: the architecture, the codebase, the infrastructure, the team, the security posture, and the IP. Investors and acquirers want to know whether the technology is a competitive asset or a liability, whether the team can execute on the roadmap, and whether there are hidden risks that will require expensive remediation.

A fractional CTO typically runs this process in two to four weeks of intensive access, working through the areas below.

The Technical Due Diligence Checklist

Architecture and System Design

• Is there a current architecture diagram that accurately reflects the production system?
• Are components appropriately separated with clear interfaces, or is the system tightly coupled in ways that make change expensive?
• What are the known scalability limits of the current architecture, and at what usage level do they become a problem?
• Are there single points of failure in the production system?
• How does the system handle failure modes — are there circuit breakers, fallbacks, and graceful degradation?
• Is the data model clean and well-documented, or has it accumulated significant drift from the original design?

Codebase Quality

• Is the codebase consistently structured, or does it reflect several incompatible architectural approaches from different periods?
• What is the test coverage, and does it cover the critical paths or just the easy-to-test code?
• Is there meaningful documentation — architecture decision records, API contracts, onboarding documentation?
• Are dependencies current and maintained, or is the project running on deprecated libraries with known vulnerabilities?
• Is there a reproducible local development environment, or does onboarding a new engineer require days of tribal knowledge?
• Is the version control history coherent — do commit messages reflect intentional decisions, or is it a series of "fix", "update", "misc" entries?

Infrastructure and Operations

• Where is the production infrastructure hosted, and is the configuration managed as code or manual?
• What does the deployment process look like — is it automated, tested, and documented?
• What monitoring exists? Are there alerts configured for the failure modes that would matter to the business?
• What is the backup and recovery posture? Has the recovery process been tested?
• What does incident response look like — is there a documented runbook, and has the team actually rehearsed it?
• Are environments (development, staging, production) properly separated, or is there risk of staging changes reaching production?

Security Posture

• Has the application been through a security audit or penetration test in the past 12 months?
• Are secrets managed properly — environment variables, a secrets manager — or are credentials embedded in code or config files?
• What is the authentication and authorization model, and has it been reviewed for common vulnerabilities?
• Are third-party dependencies scanned for known vulnerabilities as part of the CI process?
• If the product handles user data: is data encrypted at rest and in transit? Is there a documented data retention and deletion policy?
• Is there a process for responsible disclosure if a security vulnerability is reported?

Engineering Team Assessment

• How many engineers are on the team, and what is the skill distribution — seniors, mid-level, juniors?
• What is the team's attrition history? Have key contributors left recently, and why?
• Is there a clear technical roadmap that the team understands and believes in?
• How are technical decisions made — is there a clear decision-maker, or does every decision require consensus?
• Does the team have the skills required to execute the next 12 months of the roadmap, or are there skill gaps that will require hiring?
• Is there an engineering manager or tech lead who can maintain execution continuity if the CTO were unavailable?

Intellectual Property and Vendor Risk

• Does the company own its IP cleanly, or are there open-source licenses in use that create obligations?
• Are there contractor or employee agreements that clearly assign IP to the company?
• What third-party services does the product critically depend on, and what happens if one goes down or changes pricing?
• Are there vendor lock-in risks that could make a future platform change prohibitively expensive?

Preparing for Diligence as a Founder

If you are heading into a fundraise and want to run a self-assessment before investors arrive, work through the checklist above and categorize each item as: clean, needs documentation, needs remediation before close.

Issues in the first category require no action. Issues in the second category can usually be addressed in documentation sprints of one to two weeks. Issues in the third category need to be remediated before the diligence process starts — or you need a credible plan and cost estimate to address them post-close.

The goal of diligence preparation is not to have a perfect codebase. It is to have no surprises. Investors can handle known risks with a plan. Unknown risks kill deals.

What a Fractional CTO Produces From This Process

A thorough technical due diligence engagement typically produces a written report covering: summary findings, a risk register with severity ratings, a prioritized remediation plan, and a technical roadmap assessment. The report serves both the immediate purpose — supporting the fundraise — and a longer-term purpose as an engineering priorities document the team can execute against.

If you need a technical due diligence assessment before your next raise, or you are evaluating a technology acquisition and need a credible third-party assessment, talk to the Clixo team.