“Can you evaluate their technology stack by Friday? We need an answer before the weekend.” Not an ask you want to receive as a Due Diligence Professional

It was a Monday afternoon when a Partner called with an urgent request that’s become increasingly common. Their target company—a Series B Fintech startup—claimed their “proprietary real-time risk engine” could process 100,000 transactions per second with sub-millisecond latency. The company was seeking to raise $50 million, investors were working to get in the round, and our Partner had exactly 96 hours to make a go/no-go decision.

Most technical due diligence firms would have asked for two weeks minimum. We took the engagement and risk of failure.

Ninety-six hours later, we delivered a comprehensive technical assessment that shattered the company’s claims. The “proprietary” engine was largely a collection of open-source components with minimal customization. The impressive transaction volumes existed only in isolated test environments with pre-processed data. Most damaging: under realistic load conditions, the system could handle maybe 10,000 transactions per second before critical failures occurred.

Our partner walked away from the deal. Their primary competitor didn’t.

Six months later, that competitor wrote down 50% of their investment when the platform catastrophically failed during holiday transaction loads, exactly as our analysis had predicted.

This case illustrates why we developed our “Four Days to Technical Truth” methodology: delivering comprehensive technical assessments within the compressed timelines that modern decisions making demands.

The Rapid Assessment Challenge

Traditional technical due diligence faces a fundamental tension. Thorough evaluations typically require weeks or months—time that competitive deal processes rarely allow. Yet rushing technical assessments can create massive blind spots that lead to expensive mistakes.

The solution isn’t choosing between speed and accuracy. It’s developing systematic approaches that deliver technical truth within investment timelines.

Day One: Architecture Archaeology

The first day focuses on what we call “technical archaeology”—excavating the fundamental structural decisions that determine a system’s scalability, maintainability, and resilience.

Morning Session: System Architecture Deep Dive

We begin with intensive interviews with the CTO or lead architect, focusing on three critical areas:

Data Architecture: How is information structured, stored, and accessed? We map data flows from input to output, identifying bottlenecks and single points of failure. Companies with solid foundations can draw their data architecture from memory. Those with problems deflect to high-level abstractions.

Integration Patterns: How does the system communicate with external services, APIs, and databases? We examine error handling, retry logic, and graceful degradation strategies. These details reveal whether the system was built for production or proof-of-concept.

Scaling Philosophy: What’s their approach to handling increased load? Horizontal vs. vertical scaling strategies, database sharding approaches, caching layers, and load balancing decisions. We can quickly distinguish between systems designed for growth and those that will hit walls.

Afternoon Session: Technology Stack Analysis

We conduct a comprehensive review of technical choices in a group format:

Framework and Language Decisions: Are they using battle-tested technologies or bleeding-edge experiments? Both can be appropriate, but the reasoning reveals technical judgment and risk tolerance.

Database Choices: SQL vs. NoSQL decisions, consistency vs. availability trade-offs, and backup/recovery strategies. Poor database architecture kills more scaling plans than any other single factor.

Third-Party Dependencies: What external services does the system rely on? We evaluate vendor lock-in risks, API reliability, and fallback strategies. Heavy dependence on immature third-party services often indicates insufficient internal technical capability.

Day Two: Team and Process Evaluation

Technology is only as reliable as the team building and maintaining it. Day two shifts focus to the human infrastructure.

Morning Session: Technical Team Assessment

Individual interviews with senior engineers, focusing on:

System Understanding: Can they explain the architecture they’ve built? We’re not testing coding skills—we’re assessing comprehension of their own systems. Engineers who truly understand their platforms can discuss trade-offs, limitations, and future challenges fluently.

Problem-Solving Approach: How do they handle complex technical challenges? We present hypothetical scenarios and evaluate their reasoning processes. Strong engineers think systematically about edge cases and failure modes.

Technical Debt Awareness: Do they understand their system’s limitations and the shortcuts they’ve taken? Honest assessment of technical debt indicates mature engineering judgment.

Afternoon Session: Development Process Review

We examine the systematic approaches that distinguish professional engineering from ad hoc development:

Code Review Practices: How do they ensure code quality? Peer review processes, automated testing coverage, and coding standards enforcement.

Deployment Procedures: How do they ship code to production? Automated deployment pipelines, rollback procedures, and feature flag strategies indicate operational maturity.

Incident Response: How do they handle system failures? Post-mortem processes, monitoring systems, and on-call procedures reveal whether they’ve planned for production realities.

Day Three: Reality Testing and Risk Assessment

The final assessment day separates marketing claims from technical truth through systematic stress testing and scenario analysis.

Morning Session: Performance Validation

We design and execute tests that simulate realistic operating conditions:

Load Testing: Can the system handle claimed transaction volumes? We test with realistic data sets, not demo-perfect scenarios. This often reveals the gap between theoretical capability and practical performance.

Concurrency Testing: How does the system behave under simultaneous user loads? Many systems work perfectly with single users but collapse under concurrent access patterns.

Data Volume Testing: How does performance degrade as data volumes grow? Systems often perform well with test datasets but fail with production-scale information.

Afternoon Session: Risk Analysis and Future Planning

We conduct comprehensive scenario planning:

10x Growth Scenarios: What breaks first when the company scales dramatically? We identify the most likely bottlenecks and estimate costs to overcome them.

Failure Mode Analysis: What happens during system outages? We evaluate backup systems, data recovery procedures, and business continuity planning.

Technical Evolution Path: Can the current architecture support the company’s roadmap? We assess whether fundamental restructuring will be required and estimate associated costs and risks.

Day Four: Write Up

On day four Osparna writes up its findings and delivers a comprehensive report to our client.

The Methodology’s Power

Our four-day framework succeeds because it combines deep technical expertise with systematic skepticism. As former builders, we know what questions reveal architectural strengths and weaknesses. We understand the difference between systems built for demos and those engineered for production.

The critical insight: most technical problems reveal themselves quickly when you know where to look. Scalable architectures feel different from fragile ones during technical discussions. Experienced engineering teams communicate differently than those managing systems they don’t fully understand.

Measurable Results

Using this methodology, we’ve evaluated companies across Fintech, Healthtech, and enterprise software sectors. Our technical assessments have:

• Helped clients avoid investments with fundamental technical flaws
• Identified technically sound opportunities with sustainable competitive advantages
• Revealed cases where technical capabilities exceeded marketing claims
• Provided negotiation leverage in deals by identifying specific technical risks

The Speed-Accuracy Balance

Four days isn’t long, but it’s sufficient time to distinguish between technical substance and technical theater. The key is systematic evaluation: comprehensive frameworks applied by experienced technical evaluators who understand both the possibilities and limitations of technology.

In our experience, most critical technical truths emerge within 96 hours when you know how to look for them. The alternative—weeks of unfocused evaluation—often produces reports that are longer but not necessarily more accurate.

Because in technology investing, precision matters more than perfection. And speed without accuracy is just expensive gambling.

Ready to discover what four days of systematic technical evaluation can reveal about your next potential investment