Prototyping & exploration — Field Notes

GITHUB

LDLR DESIGN FIELD NOTES

Two geometries

Gimeno opens a million-line PR without dropping a frame: one geometry for code, a second for everything human.

BY ALBERTO GIMENO / SEP 23, 2026

Rendering huge pull requests in the GitHub Copilot app

Any ‘is the user interacting?’ check has to be one your own side effects can’t satisfy.

Why it matters

— A 2,200-file, million-line PR opens scrollable, with 400 inline review comments

— Two geometries: deterministic prefix sums for code, measured dynamic blocks for comments

— They rejected per-block ResizeObservers for one idle-gated measurement pass near the viewport

— An autopilot drove the real app unattended, reading health signals from disk logs

Read on GitHub →

Craft & detail Prototyping & exploration

DESIGN SYSTEMS COLLECTIVE

LDLR DESIGN FIELD NOTES

The bill under the demo

45 seconds to generate the screen, three hours to make it honest. Singh's metric: time to trusted output.

SEP 18, 2026

The 'Fix-it Tax' of Generative UI

It is a fast proposal with a bill folded underneath.

Why it matters

— Green rectangles for switches, raw hex for surface.base, focus states stripped for cleanliness

— Generated UI delivers the appearance of decisions without the decision trail

— Cleanup is archaeology: find the assumption, trace the rule, replace it without breaking structure

— Her fix: a pattern contract written before generation, tokens and boundaries included

— One innocent token had failed contrast testing six months earlier; no model knows that

Read on Design Systems Collective →

Systems & primitives Prototyping & exploration

FIGMA

LDLR DESIGN FIELD NOTES

The prototype pitched

King vibe-coded the WebGPU canvas he’d imagined for years, recruited the team it earned, and shipped in two months.

BY ROGIE KING / SEP 1, 2026

Behind the build: Generative plugins and shaders at Figma

While it had taken us months to build progressive blur in Figma Draw, I could now create the same shader effect with one simple prompt — maybe two to nail it.

Why it matters

— Show, don’t tell: the “FigGPU” prototype did what a years-old obsession and a Loom in Slack never could

— Yassir Solomah validated it for real, replacing WebGL 2 fragment shaders with sandboxed WebGPU pipelines

— Two months to Config: no PRDs, no crits, demos over formal reviews, one massive Slack channel

— The reversal: vibe-coded prototypes served designers but failed developers and PMs — static mocks realigned the team, then code took over

— PropsKit, a web-components Figma UI kit, exists so agent-built plugins look and feel native

Read on Figma →

Prototyping & exploration Craft & detail Cross-functional & process

DESIGNER FUND

LDLR DESIGN FIELD NOTES

Protect the search

Saarinen, Aufmann, and Kumar widen design’s search with AI: context gathering in, critique and copy deliberately out.

BY KARRI SAARINEN, CHARLIE AUFMANN, AND ISHA KUMAR / AUG 12, 2026

Protecting the Thinking Behind Great Design | Inside Linear's Design Team

When you can do anything, what you choose not to do is far more important than doing everything much faster.

Why it matters

— Karri's /linear-way skill interrogates 40k customer requests for the real problem

— The wiki ask, reframed: let context live where execution lives

— Kumar caps AI at 20–30% of net-new design work, on purpose

— Aufmann brings raw customer quotes to review, so debate runs on evidence

— Define what good looks like first — otherwise the output can never fail

Read on Designer Fund →

Craft & detail Critique & decision-making Prototyping & exploration

PROOF OF CONCEPT

LDLR DESIGN FIELD NOTES

The next user isn't human

Hoang names the discipline forming around agents as users: access, context, tools, and parallel paths for two minds.

AUG 2, 2026

Agent Experience

Why force an octopus to open a jar with two tentacles because you as a human have two hands?

Why it matters

— Agents are users now: design for access, context, tools, orchestration

— Same goal, parallel paths: search bar for humans, direct query for agents

— Agents don't complain; observability must surface retries, dead ends, silent failures

— Documents go bidirectional: hierarchy for people, structure and metadata for agents

— He asks his agents to run a retro and file feedback

Read on Proof of Concept →

Systems & primitives Prototyping & exploration Cross-functional & process

LINEAR

LDLR DESIGN FIELD NOTES

Borrowing our habits

Boom builds a supersonic airliner and its engine at once, on software’s rhythm: short cycles, real parts in hand fast.

JUL 15, 2026

Boom Supersonic builds as fast as it flies

A part you can hold teaches you more than a part you can only model.

Why it matters

— Building Overture and its Symphony engine together, refined against each other in-house

— Aerospace habits date to the 1990s: long planning, slow specialist handoffs

— Every engineer is expected to build tools that streamline their own work

— Software engineers sit with hardware teams instead of a separate world

— XB-1 already flew past the speed of sound without a boom reaching the ground

Read on Linear →

Prototyping & exploration Cross-functional & process

GEOFFREY LITT

LDLR DESIGN FIELD NOTES

Understanding is fluency

Litt argues understanding agent-written code keeps you fluent enough to have the next idea, with four techniques.

JUL 2, 2026

Understanding is the new bottleneck

A quiz is a speed regulator.

Why it matters

— Agents now verify their own work, so understanding buys creative participation instead

— A project is many loops, and fluency is what lets you have the next idea

— His /explain-diff skill outputs literate diffs: background first, intuition before code

— Every explainer ends in a five-question quiz he won't ship without passing

— Micro-worlds: he had an agent build a debugger so he could learn the system himself

Read on their blog →

Critique & decision-making Prototyping & exploration Cross-functional & process

UX COLLECTIVE

LDLR DESIGN FIELD NOTES

The what slips

A product designer ships an agent that grades agents, and feels the what start sliding toward the machine.

BY FRANCISCO BARRERA AROS / JUL 10, 2026

The crisis of the what

Nobody handed the what to AI in a strategy meeting.

Why it matters

— He's a product designer with no technical background who shipped an agent that grades agents

— The how was always negotiable; he argues the what is now in play too

— He parts ways with Thompson's map, which holds the what until superintelligence

— The handover comes through small decisions that look like pure execution

— What survives, in his read: judgment built through experience, intuition with scars

Read on UX Collective →

Critique & decision-making Prototyping & exploration

TECH.EU

LDLR DESIGN FIELD NOTES

Defending the draft

Jon Steinback's Marker leaves stealth with a $13M seed and a thesis: AI should write with you, never for you.

BY JOHN REYNOLDS

AI writing startup co-founded by DeepMind creative lead raises $13M seed investment

"I believe they will choose something that values the craft" (Jon Steinback, Marker CEO)

Why it matters

— Co-founded by ex DeepMind creative lead Jon Steinback and Ryan Bowman

— $13M seed led by Index Ventures, with LocalGlobe and heavyweight angels

— Angels include Steve Newman, whose Writely became Google Docs

— Built for ideation, drafting, revision, and collaboration, not automated output

— Early testers are writing blogs, memos, novels, and wedding speeches

Read on Tech.eu →

Craft & detail Prototyping & exploration

JAMIESON ROTHWELL

LDLR DESIGN FIELD NOTES

Shipping binaries now

After three decades built on the handoff, Jamieson Rothwell ships working software and treats builds as design.

MAY 11, 2026

Product Design in 2026: Am I still a designer?

Shipping is the new designing.

Why it matters

— The old ritual, design then hand off blueprints, is over for him.

— LLMs and coding agents turn static design into active construction.

— Local-first as a design choice: his tool Warren guards data ownership.

— A small cross-platform system, Sitka, keeps React, HTML, and Swift aligned.

— Barrier to entry collapsed; the barrier to greatness is still taste.

Read on Medium →

Prototyping & exploration Systems & primitives Craft & detail

GEORGE XING

LDLR DESIGN FIELD NOTES

Shipping solo

A solo builder lays out the agent framework, test automation, and remote setup that made his product workflow far faster.

MAY 6, 2026

Prototyping & exploration Systems & primitives

DESIGN WITH AI

LDLR DESIGN FIELD NOTES

Five habits for AI work

Notes from ÌníOlúwa Abíódún's talk on shipping AI agents: scope sharply, write to think, then explore rough prototypes.

MAY 24, 2026

Prototyping & exploration Craft & detail

GOOGLE LABS

LDLR DESIGN FIELD NOTES

Vibe design gets a canvas

Stitch grows into an AI-native infinite canvas: design agents, voice critique, and DESIGN.md moving between tools.

BY RUSTIN BANKS / MAR 18, 2026

Introducing "vibe design" with Stitch

Close the gap from idea to reality in minutes rather than days.

Why it matters

— Start from business objective and intended feeling, not a wireframe

— An agent manager tracks parallel explorations across the infinite canvas

— DESIGN.md exports design rules as agent-friendly markdown between tools

— Voice critique makes real-time updates while you stay in flow

— Stitch screens together and press play to preview full journeys

Read on Google Labs →

Prototyping & exploration Systems & primitives

MEDIUM

LDLR DESIGN FIELD NOTES

AI ate the PM talk

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

POSTHOG

LDLR DESIGN FIELD NOTES

When FOMO ships early

PostHog's CEO on shipping AI before it worked, the architecture fix that turned it around, and betting the product on agents.

BY JAMES HAWKINS / MAY 1, 2026

PostHog's next chapter

FOMO came ahead of progress.

Why it matters

— A one-shot assistant shipped early, returned empty graphs, and felt half-useful.

— The fix was a single query loop so the agent could iterate.

— Agents now create most new dashboards, with MCP usage roughly doubling monthly.

— The bet: a headless, proactive product that ships fixes while you sleep.

— Hawkins is candid about UX churn, and why the short-term pain is worth it.

Read on PostHog →

Prototyping & exploration Critique & decision-making Systems & primitives

BOOTCAMP (MEDIUM)

LDLR DESIGN FIELD NOTES

Design relief

An early-career case for building leverage: encode taste into tools and remove friction over polishing more screens.

DEC 18, 2025

Stepping Into 2026 as a Designer (When You're Still Early in Your Career)

I wasn't designing outputs anymore. I was designing relief.

Why it matters

— Polished screens are cheap now, so execution alone no longer carries value.

— He stopped refining artifacts and started building small tools that remove friction.

— A junior's edge: no fixed identity, so quiet experiments come easier.

— Taste still matters, but it scales only once you encode it.

— The move is from producing screens to shaping how they get produced.

Read on Bootcamp (Medium) →

Systems & primitives Prototyping & exploration

UX COLLECTIVE

LDLR DESIGN FIELD NOTES

AI holds the context

Shakir’s workflow: the AI holds context across Linear, Slack, and research while the designer does the thinking.

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

The system is the handoff

Microsoft folded Copilot into four surfaces tied by one ‘Throw and Catch’ pattern: the pattern is the system.

BY JON FRIEDMAN / MAY 12, 2026

A simplified system

Intelligence without continuity can feel like an interruption instead of a thought partner.

Why it matters

— Four canonical Copilot surfaces, not scattered features per app.

— 'Throw and Catch' governs handoff between the four surfaces.

— Context persists across apps. The conversation does not restart.

— On-canvas narrows from exploration to document focus on selection.

Read on Microsoft Design →

Systems & primitives Prototyping & exploration Craft & detail

FIGMA

LDLR DESIGN FIELD NOTES

The canvas reads code

McMillin reframes canvas, code, and PRD as one system: an agent translates, and judgment moves through both.

BY BRETT MCMILLIN / APR 30, 2026

Workflow lab: Expanding the canvas with Figma MCP

The artifact isn't a bug report. It's a shared reference for a design conversation.

Why it matters

— Agents surfaced ten product states the original canvas missed.

— Visual diff replaces the bug ticket as a design artifact.

— On canvas exploration stays cheap. In code every direction costs.

— Source of truth becomes connected artifacts, not one canonical file.

Read on Figma →

Prototyping & exploration Cross-functional & process Systems & primitives

MAGGIE APPLETON

LDLR DESIGN FIELD NOTES

The design bottleneck

Appleton reads Yegge’s chaotic agent orchestrator as design fiction: the coding bottleneck fell, the design one stayed.

JAN 23, 2026

Gas Town’s Agent Patterns, Design Bottlenecks, and Vibecoding at Scale

Design becomes the limiting factor: imagining what you want and figuring out the gnarly details to make it real.

Why it matters

— When agents write faster than you design, vibe-designing is a footgun.

— Mayor/Polecat hierarchy sketches a real coordination pattern for agents.

— Code distance shifts with domain, stakes, and team size.

— Infrastructure matters more than models. Validation loops, not smarter agents.

Read on their blog →

Critique & decision-making Cross-functional & process Prototyping & exploration

MAGGIE APPLETON

LDLR DESIGN FIELD NOTES

The PR can’t plan

Agents collapsed the implementation window, and the alignment checkpoints that lived inside it went with it.

APR 13, 2026

One Developer, Two Dozen Agents, Zero Alignment

Code is so cheap we don't properly stop to think before prompting it. We lose more alignment points.

Why it matters

— Planning and building are no longer separate phases. The tools still are.

— The PR now carries upstream checkpoints it was never designed for.

— Most alignment context lives in people's heads. Agents can't reach it.

— Ace is a research prototype. The diagnosis is sharper than the fix.

Read on their blog →

Cross-functional & process Critique & decision-making Prototyping & exploration

RAUNO FREIBERG

LDLR DESIGN FIELD NOTES

Minimap, jank, blur

Rauno tried to solve 'scroll back' with a minimap. The minimap caused jank, the jank needed a blur, and the blur almost worked.

Field Notes

The jank gets increasingly worse when you actually choose to scroll to another message.

Why it matters

— Each solution reveals the next constraint: scroll, minimap, jank, blur.

— AI summaries failed: you remember what you typed, not a summary.

— Blur-and-stack beats layout collapse because fewer objects move.

— Keeping the composer visible preserves task context in minimap mode.

Read on their blog →

Critique & decision-making Prototyping & exploration Craft & detail

LINEAR

LDLR DESIGN FIELD NOTES

No Miro board in Athens

Linear flew designers and engineers to Athens and shipped a working build by Friday. The part worth lifting is the trust.

BY KARRI SAARINEN / MAR 28, 2024

How we redesigned the Linear UI (part II)

It's always better to do a redesign quickly. Otherwise, you will block almost every project and create design debt.

Why it matters

— Mornings for design iteration, afternoons for engineering pairs.

— Working build behind a feature flag by Friday.

— Compressed loop only works when trust replaces handoff rituals.

— Specific technical calls: LCH over HSL, Electron cross-platform tax.

Read on Linear →

Craft & detail Cross-functional & process Prototyping & exploration