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Philosophy

Why I Document Every Mistake

Alexander Snyder·February 10, 2026·6 min

Six weeks into a data enrichment engagement, I discovered our deduplication query was broken. Not slightly off — fundamentally broken. We were sending duplicate records to a paid API, burning through the client's budget on data we already had.

I did the math. 19% of total spend was preventable waste. Not 2%. Not 5%. Nineteen percent.

Here's what happened next: I built a slide deck quantifying every dollar of waste, explaining exactly how the bug occurred, what we'd done to fix it, and what safeguards we'd put in place to prevent it from happening again. Then I presented it to the client.

They expanded the engagement.

The instinct to hide

The natural response to a mistake this significant is damage control. Minimize the impact. Reframe the narrative. Bury it in a broader status update where it becomes one bullet point among twenty.

I've seen this play out at every firm I've worked with or competed against. The quarterly business review shows a tidy success story. The failures get mentioned in passing — "we encountered some data quality challenges" — and the conversation moves on. Nobody asks follow-up questions because nobody wants to hear the answers.

This works in the short term. The client stays happy. The engagement continues. Everyone's comfortable.

But it destroys something more valuable than comfort: trust.

What transparency actually looks like

Documenting mistakes isn't about performative honesty. It's about building a specific kind of relationship with the client — one where they trust your assessment of what's working because they've seen your assessment of what isn't.

For the distribution engagement, the mistake documentation included:

  • Root cause analysis. The dedup query was matching on city name strings across tables with different naming conventions. "Portland" vs "PORTLAND" vs "Portland, OR" — SQL string comparison treated these as different records.
  • Exact financial impact. 19% of API spend, broken down by batch, with a timeline showing when the bug was introduced and when it was caught.
  • The fix. Switched to ZIP code matching with RTRIM/LTRIM/UPPER normalization. Added a Python-side set check as a safety net before any paid API call.
  • Safeguards. New monitoring that flags yield per batch — if new records drop below expected rates, the pipeline stops automatically.

This isn't a confession. It's engineering documentation. The same rigor we bring to building systems, applied to understanding failure.

Why clients expand after seeing failure reports

The distribution client expanded the engagement for a specific reason: they now trusted our numbers.

When we said a pipeline was processing 100K+ properties at $0.05 per contact, they believed us. Not because the number was impressive — because they'd seen us present the number that wasn't impressive. They knew that if something was broken, we'd tell them.

This creates a counterintuitive dynamic. The engagement where we made the biggest mistake became our most trusted relationship. The client references our failure documentation as a positive in conversations with their board. "Our data partner documents everything, including what goes wrong."

The competitive advantage of honesty

Most AI consultancies sell on capability. Their decks showcase what they can do. Their case studies highlight successes. Their references are curated.

We sell on transparency. Our case studies include what broke. Our metrics include the waste. Our references will tell you about the 19% because we told them about it first.

This filters for the right clients. Companies that want a vendor who tells them what they want to hear — they'll hire someone else. Companies that want a partner who tells them the truth — they call us.

The filtering is the feature. Every client we work with knows exactly what they're getting. That alignment is why every engagement has either continued or expanded.

How we operationalized this

Documenting mistakes isn't a cultural value statement. It's a process:

  • Every engagement has a decision log. Not just what we decided — why we decided it, what alternatives we considered, and what we expected to happen.
  • Every pipeline has yield monitoring. If something breaks, we know within one batch cycle. We don't discover waste in a quarterly review.
  • Every failure gets a cost quantification. Not "some records were duplicated" — "847 duplicate records at $0.12 each = $101.64 in preventable spend."
  • Every client sees the full picture. Weekly updates include what went wrong alongside what went right. No curation. No cherry-picking.

This takes more time than the alternative. Writing a failure report is harder than writing a success report. Quantifying waste requires more analysis than ignoring it. Presenting bad news requires more preparation than skipping it.

But the time investment pays for itself in trust. And trust is the only thing that turns a 12-week engagement into an ongoing partnership.

The uncomfortable truth

If you're not documenting your mistakes, you're not learning from them. You're just moving on to the next engagement and hoping the same bugs don't appear.

They will.


PurviewX is embedded AI leadership for industries that weren't built for this era. We don't build pilots — we build systems that run. Start a conversation.