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Buy-Side Diligence

Buy-side technical
due diligence.

CTO practitioner-led assessment for software, AI-native, and tech-enabled targets. Built around one question: what does this mean for the investment? Structured flexibly around your access, your timeline, and the deal you actually have.

1,500+
Investments Supported
350+
Companies Assessed
90%
Repeat Clients
$190B+
Transaction Value
20+
Avg. Leadership Experience
Who We Work With

Software companies. Tech-enabled companies. Same rigor.

Whether technology is the business or technology enables the business, the diligence rigor is the same. The depth, the questions, and the emphasis flex to the target in front of us.

Software & AI-Native

When technology IS the business

The product is the technology. Code, architecture, the AI/ML stack, scalability, and IP defensibility are the moat. We pressure-test what scales, what breaks, and what is genuinely differentiated.

Where We Go Deep
  • Architecture suitability & scalability
  • AI/ML stack, data foundations & model readiness
  • Code quality, technical debt & security
  • Engineering org, velocity & key-person risk
  • IP, open source & defensibility

Typical targets: SaaS platforms, AI-native products, dev tools, fintech platforms, marketplaces, vertical software.

Tech-Enabled & IT-Driven

When technology ENABLES the business

The product is the service. Technology powers operations, customer experience, and unit economics. We assess the IT backbone, line-of-business tools, integrations, and the data flow that holds everything together.

Where We Go Deep
  • Enterprise IT architecture & resilience
  • Line-of-business tools & ERP/CRM stack
  • Data flow, integrations & reporting
  • IT infrastructure, cloud & cyber posture
  • Internal vs outsourced tech mix

Typical targets: tech-enabled services, healthcare delivery, e-commerce ops, manufacturing & IoT, logistics, business services.

Same 360° methodology. The depth and emphasis flex to the target.

Track Record

Sector experience that holds up under scrutiny.

Hundreds of engagements across the sectors mid-market PE invests in most. Real deal types, anonymized.

Financial Services & FinTech

Trading Platforms · Wealth & Investment Mgmt · Capital Markets · Securities Finance · Payments · RegTech

Consumer Goods, eCommerce & Retail

Unified Commerce · Online Marketplaces · POS & Retail Tech · Direct-to-Consumer · Pricing SaaS

Healthcare & Life Sciences

EMR & RCM · Medical Devices · Lab Automation · Clinical Trials · Mental Health · Healthcare Analytics

Cybersecurity & Risk

OT & ICS Security · Threat Detection · MSSP Platforms · Identity & Access · Risk & Compliance

Manufacturing & Industrial Tech

Industrial Software · Robotics & Automation · Digital Twin · MES & SCADA · Aerospace & Defense

Energy, Utilities & ESG

Renewables · Oil & Gas · Water · Energy Trading · ESG Software · Subsea & Offshore

Telco, Networking & Connectivity

5G Lifecycle Automation · Network Management · Telecom Security · MSP Platforms · Fixed Wireless · IoT & M2M

Logistics, Supply Chain & Mobility

Supply Chain Analytics · Fleet & Telematics · Maritime & Shipping · Automotive Data · Couriers & Last-Mile

Media, Entertainment & Sports

VOD & Streaming · Sports & Premium Hospitality · Gaming · DXP & Content · Influencer Platforms

Legal, Professional & Business Services

LegalTech · Court Reporting · Marketing & DXP · Accounting & Tax · Professional Services

Human Capital Management

HRIS · Workforce Management · Payroll & HR · L&D · Applicant Tracking · Neuro-Inclusion

Education & Non-Profit

Higher Ed Platforms · K-12 SIS · eLearning & LMS · Crisis Training · Non-Profit Software
Mid-Market Sweet Spot
10%
30%
30%
20%
10%
<$100M $100-250 $250-500 $500-1B >$1B
Lower & Mid-Market Focus

~70% of deals sit <$500M. We also cover smaller targets, upper mid-market, and large cap.

Software vs Tech-Enabled
75% Software
Software-led, with breadth

25% tech-enabled targets where IT runs the business.

Software-Led, with Breadth

~75% of engagements are software or AI-native targets. We also cover tech-enabled businesses where IT is the backbone of operations.

A Horizontal Capability

AI is everywhere we look.

AI shows up in two ways across our diligence work. AI as the product when models, training data, and IP are the moat. AI as a feature when it's embedded inside a broader software product. Both demand their own readiness, risk, and defensibility lens, and AI runs as a horizontal thread across every area we assess.

01

AI as the Product

The AI itself is the offering. Models, training data, IP defensibility, and inference economics are central to the diligence.

02

AI as a Feature

AI embedded inside a broader product. Increasingly standard across software, with its own readiness, risk, and reliability profile.

Recent AI Engagements
Contact Center Automation Cyber Intelligence Platform Video Surveillance Translation & Content Intelligent Automation Aquaculture Monitoring Medical Imaging Legal Workflow
Engagements

Built for the deal you have.

Different deals need different depth. Six packaged engagements from early-stage exploration to upper mid-market deep-dives. All on the same methodology.

Outside-In Stealth

Validate the thesis and answer specific questions before committing. Public data, expert networks, and structured hypothesis testing without management access.

When to consider
  • Early discussions, no commitments either side
  • Pre-bid stealth mode with limited or no access
  • High-level read before further effort or spend

Red Flag

High-level thesis validation focused on top risks. Fast, focused, decision-ready. The minimum viable diligence for fast-moving deals.

When to consider
  • LOI in place or imminent
  • Limited time or budget for full diligence
  • Fast-moving deal with healthy access

Summary Report

Full risk and opportunity backlog with industry benchmarks and value creation hooks. Lighter on supporting documentation, full on findings.

When to consider
  • LOI in place with healthy access
  • Lower mid-market deals
  • Want core insights without heavy documentation

Standard Report

Full deep-dive with risks, opportunities, mitigations, industry benchmarks, and a value-creation roadmap. The default for mid-market deals.

When to consider
  • LOI signed, exclusivity or healthy access
  • Mid-market deals
  • Want full risk and opportunity profile

Extended Report

Deepest scope with value creation depth, complex carve-outs, and full documentation. Built for upper mid-market and large cap transactions.

When to consider
  • Deep access, complex business or carve-out
  • Upper mid-market or large cap
  • Need full value creation roadmap at close

Competitive (2-Phase)

Combined stealth and standard diligence. Phase 1 surfaces red flags with limited access. Phase 2 deepens once access expands through the bidder rounds.

When to consider
  • Competitive process with multiple bidders
  • Limited initial access transitioning to full
  • Want to de-risk early, deepen later
Not sure which fits your deal? Tell us about it.
360° Methodology

Six core areas. Two horizontal threads. One connected view.

Every engagement runs through the same 360° lens. Six functional areas form the spine, with AI and Cybersecurity threaded horizontally across all of them. Built for deal speed: structured tools, senior practitioners working alongside your team, and every finding tied to a commercial implication your IC can act on.

01

Strategy & Roadmap

Product strategy, roadmap state and feasibility. Are technical priorities aligned with the business thesis, and can the team actually ship them?

02

Architecture, AI, Data & Code

System design, AI maturity, data foundations, and code quality. Suitability for the strategy with depth in scalability, security, and robustness.

03

Customer Support & Services

Professional services and customer support capabilities. CSAT signals, escalation patterns, and what they reveal about code, architecture, and IT.

04

Organization & Leadership

Team size, skillset, structure, and gaps. Leadership capability and technical horsepower. The ability to execute the roadmap that has been promised.

05

SDLC & Ability to Execute

Execution capability, SDLC maturity, quality and DevOps practices. Can they ship safely, predictably, and at the cadence the thesis requires?

06

IT Infrastructure

Cloud and infrastructure adequacy, costs, and resilience for the investment thesis. What scales, what breaks, and what costs more than it should.

AI
Capabilities · Risks · Defensibility
Cybersecurity
Ransomware. Breach Risk. Posture · Controls · Compliance
Common add-on areas
Code & OSS Scans Product Deep-Dive Carve-Outs Professional Services Corporate IT Data Optimization

For specialized work like advanced cybersecurity, OSS tooling, and expert networks, we tap our preferred partner network as an extension of the team.

Resources

Want to see what good looks like?

The Sample Report shows how we structure findings, evidence, risk ratings, and remediation costs. The TechDD Guide is a complete primer on what to look for and what to ask.

The Definitive Guide to
Technical Due Diligence.
A practitioner's playbook for investors and founders
Free Guide  •  12 Pages

The Definitive Guide to Technical Due Diligence

Twelve chapters covering the 6-stage process, deal breakers, common red flags, what good targets look like, and the complete value creation playbook. Drawn from 1,500+ real engagements.

Technical Due Diligence
STONEBRIDGE
Confidential  •  PE Buy-Side
Sample · Redacted
Sample Deliverable

TechDD Sample Report

See how we structure findings, risk ratings, evidence, remediation costs, and the “So What” your investment committee can act on. Redacted. Real format.

FAQ

Common questions.

Do you cover IT-enabled companies, not just software?
Yes. We work with both. When the target is a software or AI-native business, our focus is heavy on architecture, AI/ML stack, code quality, and scalability. When the target is tech-enabled (technology as enabler, not product), we shift the weight to enterprise IT, line-of-business tools, integrations, data flow, and the IT infrastructure backbone. Same 360° methodology, different emphasis.
What's the difference between buy-side and sell-side technical due diligence?
Buy-side TDD is commissioned by an acquirer to evaluate a target before investing. Sell-side TDD (also called Vendor Due Diligence or VDD) is commissioned by a seller to prepare for a transaction by surfacing and addressing issues before buyers do. Different commissioner, similar rigor, different angles of focus.
How do I know which package I need?
It comes down to access, timeline, and stage. Outside-In and Red Flag work for early or limited-access situations. Summary, Standard, and Extended are for once you have an LOI and full access. The Competitive package is built for processes where access expands as you progress through bidder rounds. The fastest way to figure it out is a 30-minute call where we ask a few questions about the deal.
How quickly can RingStone mobilize?
Within 5 business days for most engagements. For Red Flag and Outside-In, often within 48 hours. We staff with senior practitioners who don't require warm-up time, and we keep capacity reserved for fast-moving deals.
Who actually does the work?
Senior CTOs, CPOs, and architects with 20+ years of operating experience. We don't run a junior pyramid model. Every engagement is led by a partner-level practitioner with hands-on involvement throughout, not just at kick-off and report-out.
What does the deliverable look like?
A structured report with an executive summary, a Bird's Eye View of risks and opportunities by functional area, supporting details, and a risk and opportunity backlog with cost estimates. Designed to be consumable top-down by an Investment Committee, with depth available for technical reviewers. The Sample Report above shows the exact format.
Can you work in a competitive process where access is limited?
Yes. Our Outside-In and Competitive packages are built for exactly this scenario. We use public data, expert networks, code analysis on what's accessible, and structured hypothesis testing to give you an informed read even without full management access.
Do you support post-deal value creation?
Yes. Every diligence finding ties to a "So What" with a recommended action and an estimated cost or impact. Many of our clients engage us for Value Creation work after close. About 90% of our work is repeat or post-M&A.

Ready to scope your next diligence?

Tell us about your deal. We'll come back with a recommended package and timeline within one business day.