Mixed Methods UX Research & AI Evaluation

Research &
Prototyping.

About me

Felipe Casadei

Research goes beyond job descriptions. I take a player-coach approach, combining technical skills with research experience.

I lead mixed methods UX research across four AWS life sciences products, including Amazon Bio Discovery, helping scientists accelerate drug discovery. My toolkit spans research prioritization, product incubation, prototyping and testing, fieldwork, experiments, surveys, supervised fine-tuning, and model evaluation.

Drawing on philosophy, neuroscience, and computational linguistics, I study knowledge, language, and human judgment. With engineering, applied science, and executive leadership, I shape AI behavior and examine its effects on consumer products and professional work.

Selected UX work

Full portfolio

Amazon Bio Discovery — read research summary

My research made scientific collaboration, learning, and inspectable AI central to Amazon Bio Discovery’s product direction. I led strategic and technical studies and built working prototypes that shaped shared workspaces, evidence controls, and architectural requirements, helping leadership commit resources to a broader scientific workbench. At the program level, the AWS–MSK collaboration subsequently moved 100,000 antibody candidates from design to lab submission in weeks, compared with up to a year using traditional methods.

click to get a glimpse of how drug discovery works

Alexa for Shopping — read research summary

Product comparisons grew from thousands to a reported 10 million per month within 90 days of the team’s redesign. I led the international mixed methods research that shaped conversational behavior, guided discovery, and comparison features. Findings were reviewed by a CEO-led team and informed the data sources and architecture supporting the assistant. This contributed to a broader team effort, paving the way for an assistant later used by over 350 million customers in the year to Q2 2026, as reported by Andy Jassy.

rufus then
alexa for shopping now

Prime customer experience — read research summary

Prime teams gained a comparable view of customer experience across 22 countries, grounded in local membership value. I adapted the measurement framework and expanded quarterly surveys with conjoint analysis and contextual inquiry. The work improved the evidence used in business reviews, exposed local adoption barriers, including payment-method gaps, and helped teams prioritize product improvements. The program also secured an EU marketing pilot and later expanded to Prime sellers, extending its reach beyond my original remit.

Voice interaction at Meta — read research summary

Established motorcycle couriers as a business segment for WhatsApp and shifted success measures from message volume toward interaction quality. Through fieldwork in India, I connected communication patterns with the cognitive demands of working in motion, informing voice interaction, accessibility, and product positioning across languages and professional contexts. The work contributed to a broader shift toward messaging as work infrastructure, in collaboration with product, design, and engineering.

simulation of courier’s field of vision as they drive

Prototypes, courses & academic research

Petra

In developmentGitHub link coming soon

Petra is an AI harness for science, built to make model-generated claims traceable to their evidence. I’m developing a workbench that uses language models to extract claims and synthesize findings, with a graph connecting hypotheses to supporting and conflicting source passages.

I separate model execution from scientific authority: a policy-controlled gateway routes bounded tasks, and people review proposed changes before they enter the trusted record. PostgreSQL holds that record; Neo4j supports bounded graph traversal so researchers can inspect why a claim is supported or challenged.

For the mathematical foundations, my graph theory course starts with notation and works up to knowledge graphs and GraphRAG.

Graph prototype · sample data
miniature investigation

    Does a graph make AI more reliable?

    Source: Edge et al. · From Local to Global ↗

    AI & graph architecture
    Shared JSON Schema contracts bind the TypeScript runtime and Python workers. Neo4j is a rebuildable projection of the reviewed record; graph queries have explicit relationship and depth limits.

    Face Lab

    Active prototype

    Face Lab gives experiments on prosody and expression a working, on-device interface. I built the facial-analysis pipeline on a Raspberry Pi, with a camera feed, controls, and telemetry for inspecting how the system behaves.

    Graph theory

    Open course

    A course that teaches graph theory without assuming mathematical notation. I built sixteen chapters with visual explanations, worked examples, and quizzes, from sets and proofs to knowledge graphs and GraphRAG. The Königsberg game lets readers try crossing every bridge once before examining why the route fails.

    From Zero to Diestel is an independent companion to Reinhard Diestel’s Graph Theory, 6th edition. It follows the book’s concepts and notation, with separate research sources for the AI chapters.

    Königsberg bridges game

    Amazon Resonance

    In testing at AWS

    Researchers can turn a document of questions into a live survey, then analyze the responses in the same workspace as their other sources. Resonance uses an LLM to structure questions, add logic, estimate completion time, suggest improvements, and publish a shareable link.

    I designed and coded the workspace so analysis can continue while code, documents, and audio ingest in the background. Separate authoring and responding experiences share access and model contracts. Resonance is being tested within an AWS team of more than 100 people.

    Architecture
    Workspace · React / TypeScript / Vite
    Separating API and worker runtimes keeps ingestion from blocking interactive analysis. S3 stores sources, DynamoDB tracks state, OpenSearch Serverless indexes content, and Bedrock provides model access.
    Surveys · API Gateway + Lambda
    Authoring and responding use separately authorized Lambda functions. SQS workers handle intake and deletion. Shared RBAC, source-lifecycle, model-registry, and reporting contracts connect survey results to the research workspace; access is enforced by the services.

    Felicity’s writing skills help AI assistants revise prose while preserving the author’s meaning. They draw on pragmatics, the study of meaning in context. Grice’s cooperative principle informs checks for evidence, appropriate detail, relevance, and clarity; speech-act theory distinguishes stating a fact, making a request, and committing to an action.

    The Review and Write skills also examine common ground: what writer and reader can reasonably assume they share. Review flags consequential gaps and unintended implications; Write revises while preserving supported claims and voice. Both run in Codex and Claude Code.

    Prenatal prosody perception

    I’m designing an experiment on what a network can learn from rhythm and melody before words are intelligible. Muffled speech approximates prenatal input; the task is to distinguish languages and speech from non-speech.

    Past experiences & education

    Experience

    • Amazon Web ServicesMixed Methods UX Researcher
    • MITREPrincipal AI Engineer
    • U.S. Department of StateForeign Service Officer
    • AmazonMixed Methods UX Researcher
    • letgoUX Research Manager
    • MetaUX Research & Insights Program Manager, International Growth
    • Mastercard AdvisorsSenior UX Researcher
    • GoogleResearch Program Manager / UX Researcher
      Trust & Safety Investigator
    • YouTube (contract)Trust & Safety Coordinator

    Education

    • University of WashingtonMS Computational Linguistics (2028)
    • Columbia UniversityMS in Neuroscience
    • Martinos Center / Harvard Medical SchoolfMRI Research Fellow
    • University of São PauloBA Philosophy

    Tech stack

    Languages

    • Python
    • R
    • SQL
    • TypeScript
    • JavaScript
    • HTML / CSS

    Research & analysis

    • pandas
    • NumPy
    • scikit-learn
    • Jupyter
    • Qualtrics
    • UserTesting
    • dscout
    • Firebase

    Prototyping & design

    • Figma
    • React
    • Vite
    • Node.js
    • Hono
    • Cytoscape.js
    • VS Code
    • Git / GitHub
    • Adobe Creative Suite

    AI & infrastructure

    • PyTorch
    • Hugging Face
    • Amazon Bedrock
    • Amazon S3
    • AWS Lambda
    • DynamoDB
    • Aurora
    • Neptune
    • PostgreSQL
    • Neo4j
    • Docker
    • Raspberry Pi
    • Codex
    • Claude Code

    Podcast

    Summaries of the books and papers I’m working through, from philosophy and history to neuroscience and mathematics.

    Listen on Spotify

    Questions about my work

    What kind of research do you do?

    I combine fieldwork and interviews with surveys, behavioral data, and experiments to understand how people use technology. My current work at AWS focuses on life sciences products, AI evaluation, and prototypes that help teams test product decisions.

    What changed through your Alexa for Shopping research?

    Persistent comparisons for high-ticket purchases shipped, and multi-turn shopping conversations increased. I led the foundational research behind the comparisons and product-discovery flows. The later customer and sales figures reported by Amazon describe the whole product, rather than the impact of my research alone. Read the Alexa for Shopping case study.

    Can I explore the full portfolio?

    The full portfolio and individual case studies are password protected; contact me to request access. Request portfolio access.

    how drug discovery works

    Receptor · EGFRAntibody · GC1118ABinding site

    Opening the structure…

    Drag to rotate · scroll to zoom

    PDB 4UV7 · Lim et al., 2016Highlighted contacts are within 4 Å in the deposited structure.