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Prospective case study · Self-initiated · Not affiliated with Coupang

Director, Product Management · Customer Experience

The best customer experience isn’t one people use — it’s one they can’t live without.

World-class commerce isn’t won on price or speed anymore — Coupang already proved that. It’s won on building an experience so intuitive, so anticipatory, so completely yours that leaving it for anyone else would feel like a downgrade. That experience is the product. What follows is how I’d build it.

PureRoom S
PureRoom
4.7★(2,300)

PureRoom SUltrasonic humidifier · 4L · nursery-quiet

The read · for you
PureRoom S4.7★
22%₩72,000₩92,000
  • Quiet — like the nursery picks you keep choosing
  • Inside the budget you set — 22% off today
  • Best-reviewed of the five: 4.7★, easy to clean
22%₩72,000₩92,000
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Executive summary · the read, done for you
  • The bet: the best CX is one customers can’t live without — won on anticipation, not price or speed.
  • The unlock: AI that takes the friction and cognitive load out of deciding — not a faster chatbot.
  • The guardrail: you earn the right to anticipate by making the data safe — on-device, minimal, grounded.
  • The proof: instrument everything, let people decide what the patterns mean, and gate every ship on an experiment.

And this is just one slice of where AI can reshape the Coupang experience — far more than a single case study can hold.

The full case study is below

The customer truth

You can’t design an experience you haven’t watched.

There isn’t one journey — there are dozens, and the same person lives several. The first-time visitor. The power user who reorders on autopilot. The shopper comparing five humidifiers. The viewer three episodes into Coupang Play. The one starting a return. Each leaves a trail of signal, and a real CX practice watches all of them — not just the funnel that’s easy to chart.

The cognitive tax is highest in the gaps between the steps: the comparing, the second-guessing, the is-this-the-right-one. Speed is a symptom of getting it right — a new user reaching their first purchase in minutes — not the goal itself. The goal is to find every place a customer is spending effort the experience should be spending for them.

The shopping journey — where the tax lives

  1. First launch

    Unknowns. No signal yet to personalize from.

  2. Signup & WOW membership

    Commitment before value is felt.

  3. Search

    Translating a fuzzy intent into the right query.

  4. Product page

    Reading reviews, weighing price vs. quality vs. delivery — the comparing.

  5. Cart

    Second-guessing. Did I pick the right one?

  6. Checkout

    Friction Coupang has already largely solved.

  7. The wait & unboxing

    Rocket Delivery — the won battle.

  8. Reorder

    Re-deciding what should already be remembered.

The thesis

Most commerce AI answers questions. The opportunity is to take the work of deciding off the customer.

Amazon bolted a chatbot onto a storefront — a faster search box. That’s not the unlock. The unlock is an experience that anticipates: it reaches the product page already knowing what this customer weighs — reviews, delivery speed, price, brand, quality — and surfaces it first, summarized, half-decided. An AI block inside the page that does the reading, so the customer doesn’t have to.

The read · for you
PureRoom S4.7★
22%₩72,000₩92,000
  • Quiet — like the nursery picks you keep choosing
  • Inside the budget you set — 22% off today
  • Best-reviewed of the five: 4.7★, easy to clean
Buy now

And when the customer arrives with a goal instead of a query, the assistant carries it the rest of the way. Find a gift for someone you barely know. Pull together everything for a kid’s birthday this weekend. Turn the week’s dinners into a single cart. The customer names the outcome; the experience absorbs the dozens of small decisions underneath it. That is the moment someone says: how did we ever live without this.

Pillar · Anticipation & personalization

Use generative AI to reason. Use classical models to rank. Knowing which is which is the job.

Not every problem needs an LLM, and pretending otherwise is how you blow the budget and lose the customer to the wait. Deciding what to show, and in what order, is a ranking problem — a recommender does it faster, cheaper, and more reliably than any language model. That’s most of the surface area.

Generative earns its cost somewhere narrower: reasoning about a goal, weighing messy human criteria, explaining a trade-off in plain language. Reviews-first for one shopper and delivery-first for another is ranking. The meal-plan assistant is reasoning. The craft is routing each job to the model that does it best — and never paying LLM prices for work a smaller one nails.

Generative — reasoning

  • Carrying a goal across a whole flow
  • Weighing messy, human criteria
  • Explaining a tradeoff in plain language
  • Finding the substitute that actually works

Classical — ranking

  • What to show, and in what order
  • Reviews-first vs. delivery-first per shopper
  • Fast, cheap, proven at scale
  • The default for most of the surface area

Pillar · Trust by design

You earn the right to anticipate by making the knowing safe.

Anticipation requires knowing the customer well — and you only deserve that intimacy if the architecture makes it safe by default. Security isn’t the compliance team’s checkbox. It’s a feature the customer can feel.

Keep it on the device

Where it can, the customer’s patterns live with the customer — not in a warehouse.

Collect the minimum

Data has to earn its keep. If it doesn’t change the experience, it isn’t collected.

Scope access tightly

Most of the system can’t touch most of the data, most of the time.

Opt out without penalty

Anonymized cohorts still reveal trends without exposing a person. Leaving stays a good experience.

Never invent in the funnel

Every price, delivery date, and claim is grounded in the live catalog — a confident wrong answer at the moment of purchase costs more than the sale.

Stays with you
On your device
  • Your patterns
  • Your history
  • What you weigh
Only minimal, anonymized data crosses over
Leaves — minimal
In the cloud
  • Minimal, scoped
  • Anonymized cohorts

Pillar · Measured relentlessly

The AI learns the patterns. People decide what they mean.

Every step is instrumented — not to surveil, but to see what’s actually working. The AI surfaces the patterns; people decide what they mean, because a pattern is never a reason on its own. Experimentation gates the rest: A/B, causal inference, feedback loops.

“Did they buy” is the weakest signal in the set. Did they come back unprompted? Did they wander into a new category? Did they trust the assistant enough to hand it the next decision? That’s the scoreboard that matters.

None of this has to be built from scratch. A self-hosted experimentation platform — GrowthBook, for one — gives you feature flags, A/B assignment, and Bayesian readouts while keeping every event on infrastructure you control. Self-hosted on purpose: the measurement layer has to honor the same privacy line as everything else.

As a customer who just wants it to be easy — which is more appealing to you?

Returned

Did they come back unprompted?

Explored

Did they try a new category?

Trusted

Did they let the assistant carry the next decision?

Converted

The floor, not the ceiling.

The hard parts

The vision is the easy part. Here’s what’s actually hard.

Put an LLM in the core funnel for tens of millions of customers and it’s a latency-and-cost problem long before it’s a feature. So you cache hard, route to small models by default, and spend the expensive calls only where they change the outcome.

You hold a hard line between reducing decision fatigue and manufacturing it: the assistant serves the customer’s goal, even when that means a smaller cart today. And you localize for real — Korean shopping behavior isn’t American behavior with translated buttons.

And you hold the long view. AI in the funnel invites a parade of short-term asks — investors and customers want the flashy feature now. A Director sees the trade-off the room doesn’t: which of those wins a quarter and quietly costs you trust, latency, or the next year. You ship the ones that compound, and you say no — out loud, with the reasoning — to the ones that don’t. Naming the hard parts is how you prove the vision is built, not dreamed.

Why me

I build this kind of thing. You’re using one right now.

This portfolio runs on a customer-facing LLM I designed and shipped — guardrailed, grounded, evaluated against a 116-question test set, cost-managed with prompt caching, with a privacy classification layer deciding what it will and won’t say. The same discipline this role needs, already in production.

Before that: a checkout and donation flow redesign that lifted completion 35%; a government platform built 0-to-1 that cut a core workflow by 95% and scaled to millions at 100% WCAG; and a habit of anchoring every decision to a real person, not a persona.

Where I’d ramp: operating an LLM at full B2C scale, and deeper fine-tuning — both adjacent to work I’ve already shipped, not new terrain. And Korea isn’t an abstraction to me. It’s personal.

This is how I think about the problem.

If this is the kind of thinking your team wants on this problem, let’s talk.

Start a conversation

Notes & credits

  1. This is a self-initiated, prospective case study. It is not affiliated with, endorsed by, or commissioned by Coupang. Coupang and the “Rocket” name are referenced descriptively; no confidential information is used, and every figure shown is illustrative.
  2. Product names, reviews, and prices in the mockups are invented for illustration. The on-page assistant is an experimental tool scoped to this case study — it represents James’s professional approach, not Coupang and not James himself.

Product photography by Felicia Buitenwerf, deep bhullar, volant, Jopofa Bolt Unsplash.