Emotional
Throughline
A practice framework for designing emotionally coherent product flows under real conditions.
6 recipes · 3 deliverables · by Florian Marmottin
What ETL is, and isn't
ETL is a practice framework. It formalizes a way of working developed across product missions: how to design emotionally coherent flows when you have partial user access, noisy inputs, and decisions to make across many screens simultaneously.
ETL is not a benchmarked methodology. It has not yet been validated through controlled before/after studies. What it offers is a set of artifacts and decision points that have proven workable in practice, and that any team can pick up and apply.
If you're looking for a ROI-quantified protocol with measured outcomes, this isn't that. If you're looking for a way to make emotional intent transmissible across PM, design, and dev, especially when you don't have ideal research conditions, read on.
Lineage
ETL stands on three traditions, made explicit.
Emotional design
Don Norman, Emotional Design (2004). Affect is a first-class dimension of product quality, not a layer added at the end.
Throughline
A term from dramatic writing (Stanislavski's 'through-action'), popularized in screenwriting by Robert McKee in Story (1997) as the spine of intent connecting every scene. ETL applies it to product flows.
Atmosphere
Peter Zumthor, Atmospheres (2006). Borrowed from architecture: the immediate emotional response a space produces, and the discipline of designing for it deliberately.
ETL's contribution is the protocol that makes these ideas operational for product work: auditable artifacts, sprint-compatible cadence, transferable decisions.
The Problem ETL Addresses
Emotional incoherence is a product risk. And it accumulates silently, screen by screen. Most product teams optimize at the screen level: task completion, error rate, time-on-task. These are the right metrics, but they are downstream indicators.
The cost of incoherence is not a bad review. It is a product that works correctly and feels wrong.
Three Failure Modes ETL Makes Visible
ETL is designed to surface failures that standard UX metrics do not catch.
Emotional Incoherence
Each screen is locally correct but globally incoherent. The user cannot build a mental model of where they are or where they are going. They complete tasks but don't return. A common driver of high task completion plus low retention.
Decision Drift
Without a documented emotional intent per screen, every sprint introduces micro-compromises, each reasonable in isolation, each eroding the throughline. Over months, the product no longer resembles its own design intention.
Invisible Rework Cost
Emotional problems caught late are coupled problems: copy, hierarchy, motion, and IA must usually be revisited together. By analogy with Barry Boehm's cost-of-defect curve in software engineering (Boehm, 1981; revised in Boehm & Basili, 2001), defects caught at intent stage are far cheaper to fix than the same issues caught in QA or post-release. The analogy is illustrative, not measured for design specifically.
The Protocol · 6 Recipes
Six interventions, each at the moment it costs least to make.
The 6 recipes together take under 2 hours on a new project. Applied per sprint: 15 to 30 min total. Durations reflect the author's practice, calibrate to your team.
What ETL Aims to Produce
Three outputs. Each is a design intention of the framework, what the artifacts are built to enable.
Alignment That Survives the Sprint Cycle
The Throughline Map gives PM, design, and dev a shared spatial reference. When a sprint introduces a new element, the question shifts from 'is this good UX?' to 'does this serve the emotional zone it lives in?', a question every team member can answer independently of the designer's presence.
Handoffs That Don't Lose Depth
The Annotated Prototype Sheet puts intent on record, per screen, per element. The developer doesn't have to reverse-engineer why a decision was made; the intent is documented alongside the visual.
Motion That Communicates, Not Decorates
The Motion Spec Sheet names emotional states on either side of each transition. Easing is chosen by intent, duration by cognitive load. Each transition is named by what it carries the user through, not by what it looks like.
Field Application · Fittingbox
ETL was applied during a V2 redesign mission at Fittingbox, a SaaS company in eyewear retail tech. The brief: refactor multiple pages with coherent design intent, under realistic constraints.
The user access was indirect. Most interactions were with internal decision-makers, product owners, business stakeholders. Test inputs were available but partial. There was no direct line to end-users, and no controlled study possible.
In that context, ETL operated as a synthesis framework. The objective was to collect every available emotional signal, from test transcripts, stakeholder reviews, product input, and translate that incomplete picture into coherent decisions across the refactored pages. The Throughline Map became the alignment artifact with stakeholders. The Annotated Prototype carried intent into handoff.
The mission ended before mass release of V2, so no user-facing metrics are available. What the framework did provide: a structured way to make consistent decisions across multiple pages when the inputs were noisy and the user was at distance. That, in real consulting conditions, is what ETL is for.
Three Deliverables
Three templates to apply ETL immediately on your next project.
T1 · Throughline Map
Spatial map of emotional zones. Name each zone by emotional state, not by content label. The primary alignment artifact.
Download PDFT2 · Annotated Prototype
One sheet per screen. Name the frame by its emotional state. Annotate the intent. The team can decide in your absence.
Download PDFT3 · Motion Spec Sheet
One row per transition. Name emotional states on each side. Choose easing by intent, duration by cognitive load.
Download PDFThe Designer
ETL emerged from a specific way of working: thinking spatially and systemically, perceiving the emotional arc of a product before its screens. That mode of thinking is not the method. The method is the extraction, six recipes, three deliverables, that makes this way of thinking communicable and applicable beyond its origin.
System-level intent before screen-level execution
Every component decision is anchored to a product-level intention, not to a local optimization. In practice: fewer late-stage conflicts, more coherent flows.
Deliverables designed to outlive the designer
The artifacts carry intent forward without requiring the designer's presence to interpret. The team can make aligned decisions between sprints, without losing emotional direction.
This is the test ETL holds itself to: not whether it works with its author, but whether it works without him.
Manifesto
Design that resonates does not begin with a screen. It begins with a state, that of someone who needs something. Feeling that state before drawing is not vague empathy. It is a discipline. A precision. An advantage.
Florian Marmottin · UX / UI / Motion Design
References
- Norman, D. A. (2004). Emotional Design: Why We Love (or Hate) Everyday Things. Basic Books.
- McKee, R. (1997). Story: Substance, Structure, Style, and the Principles of Screenwriting. ReganBooks.
- Zumthor, P. (2006). Atmospheres: Architectural Environments, Surrounding Objects. Birkhauser.
- Boehm, B. W. (1981). Software Engineering Economics. Prentice-Hall.
- Boehm, B. W., & Basili, V. R. (2001). Software Defect Reduction Top 10 List. Computer, 34(1), 135-137.
Exchange & Improve
ETL is a living method. Share your feedback, questions, or adaptations. Let's build on this together.
ETL · Emotional Throughline v3.0 · Florian Marmottin · studioflo.fr