Research & validation — Field Notes

BUILDING NUBANK

LDLR DESIGN FIELD NOTES

Simplicity at scale is strategy

Five lessons from serving 127 million customers, where hiding complexity is a deliberate architectural and cultural decision, not polish.

BY MARISTELA CALAZANS / FEB 16, 2026

What changes when your product reaches 127 million people

Simplicity at scale is not a design preference. It's a strategic decision.

Why it matters

— Quarterly Customer Connection visits put teams in unstable-internet, older-device reality

— Accumulated friction, not catastrophic failure, is the real loyalty killer

— Caixinhas cut a dozen fund options to a two-step habit-building flow

— Global core, local nuance shipped Colombia's Bre-B six months faster

— Intelligent friction: slowing users down protects life savings on unusual transactions

Read on Building Nubank →

UX COLLECTIVE

LDLR DESIGN FIELD NOTES

A skeptic's playbook for AI

A research leader of eight argues for measured AI adoption: pressure-tested tools, tracked outputs, and guardrails before enthusiasm.

APR 30, 2026

Thoughtful AI implementation for UXR leaders

I'm arguing for a measured approach to their usage.

Why it matters

— Pressure-test NotebookLM with likely stakeholder questions before opening access

— Capture before and after results when tuning prompts with ops

— Track who queries research repositories and how outputs shape decisions

— Half of Americans are more concerned than excited about AI

Read on UX Collective →

Research & validation Critique & decision-making

HARVARD BUSINESS REVIEW

LDLR DESIGN FIELD NOTES

AI is the new workplace confidant

Employees increasingly turn to AI for advice, support, and friendship. The researchers argue leaders must protect human connection at work.

BY CONSTANCE NOONAN HADLEY AND SARAH L. WRIGHT / MAY 1, 2026

Employees Are Relying on AI for Personal Support. That's Risky.

Research shows how AI can weaken human connection at work.

Why it matters

— More than half of 1,545 surveyed knowledge workers feel lonely at work

— Workers seek career advice, emotional support, and friendship from AI

— AI conversation can quietly substitute for, then erode, human connection

— The authors call on leaders to intervene before reliance hardens

Read on Harvard Business Review →

Hiring & team Research & validation

MEDIUM

LDLR DESIGN FIELD NOTES

AI Ate the PM Conversation

A multi-agent read of 638 Lenny pieces, June 2019 to March 2026, charting what production loses and judgment keeps.

MAR 18, 2026

What 638 Practitioner Voices Reveal About Product Manager's AI Transformation

Speed raises the bar for where rigour is applied, rather than lowering it.

Why it matters

— AI-tagged content jumped from 4% of output to 67% in three years.

— Built transparently: five Claude agents reading the corpus, the method shown in full.

— Jenny Wen argues the design process designers were taught is effectively over.

— Products become organisms that learn, pushing pricing toward outcomes, not seats.

— What endures: conviction, taste, influence, and a focus on outcomes.

Read on Medium →

Research & validation Prototyping & exploration Cross-functional & process

DESIGN SYSTEMS COLLECTIVE

LDLR DESIGN FIELD NOTES

Fully Machine-Readable Design Systems

AI reads your design system differently; structured metadata beats prose documentation. · Foundations should be always-on; components served on demand through an MCP.

MAY 14, 2026

Fully Machine-Readable Design Systems

Why it matters

— AI reads your design system differently; structured metadata beats prose documentation.

— Foundations should be always-on; components served on demand through an MCP.

— At Indeed, JSON cost five times less than Markdown for the same query.

— Progressive disclosure maps what AI needs without flooding its context window.

— The system you wrote for designers won't work for agents without a rewrite.

Read on Design Systems Collective →

Systems & primitives Craft & detail Research & validation

UX COLLECTIVE

LDLR DESIGN FIELD NOTES

How I use AI to partner on design problems

The AI holds context across Linear, Slack, and research; you do the thinking. · Code prototypes move feedback from visual details to actual UX problems.

MAY 15, 2026

How I use AI to partner on design problems

Why it matters

— The AI holds context across Linear, Slack, and research; you do the thinking.

— Code prototypes move feedback from visual details to actual UX problems.

— Bad ideas surface faster when they're running, not sitting in Figma.

— Decision tracking lives in a folder per round, not buried in comment threads.

— The longer the project runs, the more useful the accumulated context becomes.

Read on UX Collective →

Prototyping & exploration Cross-functional & process Research & validation

MICROSOFT DESIGN

LDLR DESIGN FIELD NOTES

When metrics optimize the wrong thing

Frontier AI teams optimize what's measurable, not what matters. Microsoft's user researchers want a seat at the evaluation table, as a safeguard against the metric chosen for being convenient.

BY MARTIN LINDE DANTY, RABEEZA A., ANNE KLÆRKE-OLESEN, MADHUMAY SINHA, MICHAEL O'SULLIVAN / APR 28, 2026

The missing seat at the frontier team table

When evaluation is driven primarily by available data, teams risk optimizing what is measurable rather than what actually matters.

Why it matters

— User research belongs in evaluation, not adjacent to it.

— Session-length looked strong. Task-completion cut repeat queries by a third.

— Sales-order workflow assumed isolation. Research surfaced cascading approvals.

— Concept tests caught a workflow misread that would have cost weeks.

Read on Microsoft Design →

Research & validation Cross-functional & process Critique & decision-making

MICROSOFT WORKLAB

LDLR DESIGN FIELD NOTES

The transformation paradox, in data

Microsoft's 2026 Work Trend Index covers 100,000+ Copilot conversations and surveys 20,000 workers across ten countries. Only 26 percent say leadership is consistently aligned on AI.

BY MICROSOFT WORK TREND INDEX TEAM / MAY 5, 2026

Agents, human agency, and the opportunity for every organization

Workers are ready. Their organizations aren't.

Why it matters

— One in five workers sit in the Frontier zone.

— One in ten are ready individuals blocked by the organization.

— Only twenty-six percent say leadership is consistently aligned on AI.

— Sixty-five percent fear falling behind. Forty-five percent stay in old work.

Read on Microsoft WorkLab →

Cross-functional & process Research & validation Storytelling & narrative

NUBANK DESIGN

LDLR DESIGN FIELD NOTES

Killing darlings, statistically

Nubank ran a real A/B test on whether to scale or shut down an internal HR product. The data was unambiguous; the team's reaction to it was not.

BY NUBANK EDITORIAL / AUG 27, 2025

A/B Testing for Decision of scaling or decommissioning an Human Resources product

Increased usage didn't always translate to feeling recognized — a critical insight missed without experimental

Why it matters

— A/B testing applied to decommissioning, not just feature launches.

— Internal tools deserve the same rigor as customer-facing products.

— Usage below threshold: kill it. Above: scale it.

— Hardest part isn't the data, it's letting the team accept it.

Read on Nubank Design →

Research & validation Cross-functional & process Critique & decision-making