I design products,
lead teams & ship code.

Group Product Design Lead at FTMO & OANDA

Hi, I'm JD
Jan Decker,
if we're being formal

I lead design at and ,
previously .
I listen to users & teams, think product first, and ship the design & the code to 100M+ people worldwide.

Many hats,
one job: products that work.

Pull request #482 · halden/app
Home: transfer tracker, recurring nudge, regional rules
  • ✓Design reviewJD
  • ✓Dev review2 approvals
  • ✓Checks128 / 128
  • ✓Staging QApassed
Merge → production

Growth, end to end.

I work on the whole journey, from “What is this?” to “I can't work without it.” Each stage has one question the product has to answer.

people drop off here
  1. 01 · Discover“Is this for me?”
  2. 02 · Onboard“How fast do I get value?”
  3. 03 · Activate“Did it actually work?”
  4. 04 · Engage“Why come back today?”
  5. 05 · Convert“Is it worth paying for?”
  6. 06 · Retain“Why would I ever leave?”
leak!
01

Find the real leak

The funnel shows me where people drop. Replays and five user calls tell me why.

AcontrolBnew flowwinner ✓
02

Bet small

One hypothesis, the smallest change that could prove it, and a success metric PM and data sign off on up front.

10%50%100%
03

Ship it properly

Prototype in code, ship behind a flag, measure. Experiments get the same craft as the product, because a sloppy test gives a wrong answer.

✓Fewer steps✕Welcome tour✓Visible progress
04

Keep or kill

What wins goes into the product and the design system. What loses gets written down, my own ideas included.

Together withProductEngineeringDataResearchMarketing

AI lets me build
what I used to hand off.

Native apps, 3D and production code used to mean a brief and a wait for someone else. Now I make them myself, to the same standard as the rest of my work.

Expo / SwiftUI
9:41

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Search moments

Native apps in Expo & SwiftUI.

Liquid glass, gestures and haptics, tested on a real device in my hand before I call anything done.

01
3D & Blender

Everyobject hereis mine

modeledlitrendered in Cyclesdirected in code

3D, made in Blender.

I modeled, lit and rendered the beanie, the switch and the hand on this page, then animated them in code.

02
React · Git
Plans — design
$0$12$29
Section / Plans3 cols · gap 16
export function Plans() {
return <Section title="Plans">
<Grid cols={3} gap="md">
{plans.map(p => <PlanCard {...p} />)}
</Grid>
</Section>
❯ git commit -m "feat(plans): pricing section"
[main 3f9c2a1] 3 files, +148 −12
❯ git push origin feat/plans
✓ preview deployed · review requested
feat(plans): pricing section #482
JDDEVApproved by dev · ready to merge
  • ✓Build & tests
  • ✓Visual regression
  • ✓Accessibility
Approved
DesignCodeShipApproved

From frame to merged PR.

I design whole sections, write the code and open the PR. Engineers review it like anyone else's.

03
Motion press & hold, the field answers

Interfaces you can feel.

Springs, states and micro-interactions, tuned by hand until they feel right.

04
not past herecontext windowdon't trustfilesshellbrowserMCP
I know how it works

Context, tools, limits.

I know what the model is good at, how much context it can hold, and where I stop trusting its output.

BigQueryInsightsResearchhubcustomcontextin every promptdata-backed ✓
I direct, it drafts

Every decision is still mine.

AI drafts. I set the business goal, bring the data, and review every line before it ships.

✓craftedthe bar✕looks AI-made
The bar doesn't move

If it looks AI-made, it doesn't ship.

AI speeds up the work. It doesn't lower the standard for what goes out.

Selected work.

Apps, platforms and side projects I designed. Most of them I also helped build.

FTMO Flashscore Novartis Fortuna Coca-Cola Twisto OANDA Odloodlo

Locked, for now.

No password? Ask me for one ↗
About me

Everything in its place. Mostly.

Things I like outside of work. Scroll to tidy up, drag to make a mess, click anything for a surprise.