Loris
Olivier

Nexus Fusion

My role in the project

2014_2024
product-design
product-design
user-research

Summary

Nexus Fusion gave neuroscientists at EPFL's Blue Brain Project access to millions of research resources. As Product Design Lead and frontend engineer, I refocused an engineering-led product on how researchers actually find and use data.

Key figures

86%Data never consulted

Share of data not opened after it was put online, on the measured scope. A diagnostic I initiated, not an outcome.

100Real entities

Downloaded to build an isolated sandbox prototype of the relationship module.

20Neurons

In the test circuit that turned a contested proposal into an approved proof of concept.

4Team leads convinced

My manager and the heads of the NISE, computational neuroinformatics and HPC teams.

All screens use placeholder or demo data; research data stays confidential.

My role & context
Role

Product Design Lead and frontend engineer. I led research and product design on Nexus Fusion.

  • Product design
  • UX research
  • Product strategy
  • Frontend
Timeline

2022 – 2024 · Blue Brain Project, EPFL.

Team

The NISE team in charge of Fusion, three backend engineers, and the computational neuroinformatics and HPC teams.

Methods
  • Interviews with scientists
  • Usage statistics
  • Scenario-based user tests
  • Workshops
  • Figma prototyping
  • Sandbox prototype
Stack
  • Figma
  • D3.js

01

The stakes

Millions of resources, and almost no way to find them.

An engineering-led platform

Nexus Fusion gave researchers access to millions of neuroscience resources. After several years of development led mainly by engineering, access went largely through an SDK and the tables it generated, with little overall view. Discovery and navigation were so heavy that researchers could not reach the pieces of data they needed inside each entity. One constraint shaped the work: the manager of the NISE team, in charge of Fusion, did not want researchers used to the terminal to be forced into another interface.

Nexus Fusion landing page over a 3D neuron circuit
_05

The entry point: connect, browse studios, read the documentation.

Before the redesign
Terminal session with the Nexus Python SDK listing projects and studios as text tables, then fetching one resource's parent
In the terminal: lists of projects and studios, and one parent at a time (reconstruction).
The original Nexus web app: a list of projects and a list of studios, mostly LNMC electrophysiology data
The web version of the same lists, before the redesign.

Access went through the SDK and generated tables.

02

Research

Talking to scientists, and measuring what nobody had measured.

How I built the diagnostic

Interviews

With scientists from different fields of neuroscience, to find the real needs and the problems of the existing version.

Usage statistics

I asked three backend engineers for what nobody was tracking: data uploaded, entities used in models or simulations, and how often data was viewed (never, by 1–10 users, by 11–20…).

Scenario-based tests

Researchers worked through realistic tasks from written scenarios, in test sessions and workshops.

Documented findings

Each issue recorded with the user's task, raw feedback, a recording and a design proposal.

Research in numbers

162+Scientists interviewed

5Fields of neuroscience

Biological experimentalists, simulation, cell, circuit and ion channel.

400+Test sessions

Plus 34 workshops.

Research artifacts
User test recording next to a written test report
A test report: each issue with the user's task, raw feedback, a recording and a proposal.
User test scenario sheets and a workshop with researchers
Scenario sheets and a workshop session with researchers.
What the statistics showed
Bar chart: 86% of published data never consulted; the remaining 14% split into 1–10, 11–20, 21–50 and more than 50 viewers
86% never consulted, measured. The split of the remaining 14% is illustrative.

03

What research changed

Volume was not the problem. Visibility was.

Insight 01 — Discovery

86% of the data was never opened after it was published

Before

Resources were uploaded at scale, but mostly reachable through SDK-generated tables. Nobody knew how much of it was actually used.

Research showed

The statistics I requested showed that 86% of the data had not been consulted after being put online, on the measured scope. Researchers also could not reach the useful pieces of data inside entities: navigation and discovery were too massive.

We built

We brought the features together in a web application: publication management through studios, interactive 3D visualisation, documentation, and a more spaced-out update strategy.

Search by data type and a circuit detail view
Search by data type, and a circuit's detail view with its key facts and preview.
A studio page on desktop and mobile
A studio: a set of resources published with its context, on desktop and mobile.
Two ways to read a table
Table view structure with standard and advanced modes

Table view structure: a standard mode, an advanced mode, filtering, and detail panes that expand on demand.

04

Product decisions

Turning a contested proposal into an approved experiment.

The relationship module, step by step

Entities were shown in isolation, yet science links them: a neuron belongs to a circuit, which belongs to a larger circuit. I proposed a module to explore resources through those relationships.

12Figma prototypes

A first interactive version of the idea.

100Sandbox prototype

Real entities downloaded to build an isolated prototype on actual data.

4Review

Presented to my manager and the heads of the NISE, computational neuroinformatics and HPC teams.

20Feasibility test

A 20-neuron circuit, proposed by the HPC team manager, to test the idea at small scale.

4Proofs of concept

Approved, built with D3.js on valid data provided by the head of computational neuroinformatics.

From Figma to proof of concept
Figma prototype of a Fusion studio's Relations tab: TC neuron 17 selected, its parent VPL microcircuit and the thalamoreticular microcircuit above, sibling neurons and 30 ion channels, with entity details on the side
Figma prototype: the selected neuron, the circuits that contain it and its 30 ion channels (demo data).
D3.js sunburst proof of concept: the mouse brain at the centre, then rings for four regions, their circuits, the VPL microcircuit's 40 neurons and one neuron's 30 ion channels, with the path to Kv3.1 highlighted
D3.js proof of concept, as a sunburst: brain, regions, circuits, 40 neurons and 30 ion channels, ring by ring (test data).
The objections, and how they were answered
Cost

The leads estimated the development cost of extracting that much data, connecting it and displaying it in real time.

Priority

The NISE team manager opposed adding a complex tool while experiment reports were still in development.

Data quality

The head of computational neuroinformatics questioned feasibility: some circuits have no clear, complete list of their neurons and synapses.

Answer

The HPC team manager proposed a test on a small 20-neuron circuit. It showed the potential, with clear room to improve performance and data quality, and I was allowed to build a proof of concept.

05

Design engineering

Making a proposal concrete enough for engineers to judge it.

What I built
Prototypes

A Figma prototype, then an isolated sandbox prototype built on 100 real entities.

Proof of concept

The relationship module with D3.js, on valid data from the computational neuroinformatics team.

Stack
  • Figma
  • D3.js
Organizations page on desktop and mobile
Organizations and their projects, on desktop and mobile.

06

Outcome

An approved experiment, not yet a shipped feature.

Who it helped
Researchers

They find and reuse data instead of losing it in SDK tables: data consulted went from 14% to 94%, with 2,600+ monthly active researchers on the web app.

Data producers

Their work gets seen and reused: 12,000+ reports, 20,000+ experimental data and 150+ studios published.

Engineering teams

A contested idea became a proof of concept they could judge on real data, approved by four team leads.

What changed after launch

14% → 94%Data consulted

Share of data opened after being put online, on the same scope as the initial 86% never consulted.

2,600+Monthly active researchers

On the Fusion web application.

12,000+Reports published

20,000+Experimental data published

150+Studios published

Where it stands
Established

A usage diagnostic nobody had run before, and a contested proposal taken from Figma to an approved proof of concept on real data.

Still open

The relationship module's feasibility at the scale of millions of resources, and its production release.

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