I help teamsbuild to learn.

I am a Staff UX Designer at YouTube Creator, leading prototyping and Gen AI exploration.

Inspiration
Start from a thumbnailRemix a past hitPitch me 3 titles
Type your own hunch
Madeira, 5 days of bliss12:48
Madeira: 5 days of blissLilly Sosa · 1 day ago
Lilly
My current focus

Turning hunches into high-confidence bets

I lead prototyping at YouTube Creator, helping cross-functional teams test ideas with creators before committing engineering time.

Dive in
prototype.jsonEdit me 😊Edit me 😊
{
"prototype": "Feature",
"chat": "Hello, Lilly Sosa",
"input": "Ask something",
"avatar": "Lilly",
"font": "Roboto",
"radius": 20,
"primary": "#0F0F0F",
"secondary": "#E6E6E6",
"views": 1935
}
Case studies

Some of my work

A few projects I led across YouTube Studio and Google Drive.

Inspiration tab

Helping creators find inspiration for what to make next.

I led the pivot and end-to-end design of YouTube Studio Inspiration. An AI-powered creative partner for exploring, developing, and shaping promising video ideas.

Explore
YouTube Studio Inspiration tab
Trends tab

Helping creators understand their audience’s interests.

I led the design and launch of YouTube Studio Trends, bringing channel-specific search and viewing signals into the Creator’s workflow across web and mobile.

Explore
Trends tab on mobileTrends topic detail on mobile
Notification Center

Unlocking collaboration on mobile: A 10x leap in engagement for Google Drive

As Interaction Designer for Google Drive, I led the UX for the Notification Center.

Explore
Google Drive home, with the Notifications tabGoogle Drive notifications, comments and access requests
File approvals

Collaborative Flow: Google Drive's File Approvals

I led the design of file approvals, a critical feature for unblocking team collaboration in Google Drive.

Read the Google article
Google Drive file approvals on desktop
Prototyping · YouTube Creator

From months to days.Helping creator teams build to learn.

I lead prototyping at YouTube Creator, helping cross-functional teams test ideas with creators before committing engineering time.

~10 daysto validate a feature, down from months
10 of 12said it validated a core direction or drove a major pivot
100+designers and PMs upskilled to run rapid, low-code discovery sprints
AwardAI Innovation Award, for pioneering Gen AI discovery workflows

The bottleneck

Validating a feature took months. Exploring an idea meant backend pipelines and engineering time, so good ideas waited in line and teams had few ways to test them before committing.

What I built

A starter kit of YouTube Studio UI shells, design tokens and prompt templates: Gen AI UI “legos.” Teams snap ready-made components together instead of starting from a blank screen, and get something real in front of creators within hours.

prototype.jsonEdit me 😊Edit me 😊
{
"prototype": "Feature",
"chat": "Hello, Lilly Sosa",
"input": "Ask something",
"avatar": "Lilly",
"video": "Madeira: 5 days of bliss",
"channel": "Lilly Sosa",
"comment": "Love this one!",
"font": "Roboto",
"radius": 20,
"primary": "#0F0F0F",
"secondary": "#E6E6E6",
"views": 1935
}

Enabling workflows

Discovery sprints that take a team from a hunch to creator feedback in days, without waiting on heavy backend work.

Step 1

An idea

It starts with a hunch worth testing, before anyone writes a line of backend code.

Step 2

UI legos & templates

Modular, Gen AI-ready pieces. Teams snap together ready-made components instead of building from scratch.

Step 3

A working prototype

Something real, ready to put in front of creators, without waiting on engineering.

Step 4

Learning from creators

Creators react to the prototype, so teams learn what lands before they build it. That feedback shapes what gets built next.

How it scaled

Tools only help if people adopt them, so I scaled prototyping across YouTube Creator and 6 core product areas.

Tools

A modular template ecosystem, so no prototype starts from a blank screen.

Playbook

A discovery-sprint guide that matches each hypothesis to the right tool, so teams test their riskiest assumption first.

Education

Hands-on bootcamps and workshops trained 100+ designers and PMs, and self-serve guides reached hundreds more.

What changed

  • Increased adoption of prototyping across YouTube Creator and 6 core product areas
  • Accelerated product discovery, from months to roughly 10 days on average
  • Validated direction: 10 of 12 said it validated a core direction or drove a major pivot on their concept
  • Recognized with the company-wide AI Innovation Award
Notification Center

Unlocking collaboration on mobile: A 10x leap in engagement for Google Drive

As Interaction Designer for Google Drive, I led the UX for the Notification Center.

Google Drive home on Android with the new Notifications tab
The Notifications tab in Google Drive on Android, with comments and access requests
A prompt to turn on push notifications in Google Drive

The problem

Granting file access on the mobile app was a significant friction point. Most people struggled to complete the task smoothly while on the go, and that bottleneck slowed down team collaboration and productivity.

My role

As Interaction Designer, I spearheaded the redesign of the Notifications Center. I worked closely with research, product and engineering to identify critical gaps and prioritize the right UX investments.

The approach

The goal was to streamline the collaboration pipeline, so people can stay updated and act on a file right from their phones.

Find the gaps

Worked closely with research, product and engineering to identify the critical gaps in the experience.

Invest in the right UX

Prioritized the right UX investments to streamline the collaboration pipeline.

One unified view

A centralized hub where people can stay updated and act directly on a file from the notification itself.

Mobile deep dive

Google Drive home on Android with the new Notifications tab
The Notifications tab with comments, access requests and approvals, grouped by time
One tap from home

See what changed and act on it, right from the notification.

A prompt to turn on push notifications so you never miss a thing

User feedback

“Something like this is incredibly helpful—a single, unified view. I don’t have to sort through endless emails or fragmented communication channels. Being able to tap right into the file directly from my notifications is a game-changer.”

Research participant

Impact

We delivered a centralized hub that lets people stay updated and take action right from their phones. It turned a frustrating, multi-step process into an intuitive one.

10xincrease in daily active visits post-launch
Millionsof daily actions supported
Fastertime-to-action, unblocking global teams
Inspiration tab

Helping creators find inspiration for what to make next.

I led the pivot and end-to-end design of YouTube Studio Inspiration. An AI-powered creative partner for exploring, developing, and shaping promising video ideas.

The Inspiration tab in YouTube Studio: video ideas to explore and a brainstorm panel

Overview

  • Product: The Inspiration Tab in YouTube Studio
  • My role: UX Design Lead
  • Team: 1 UX Design Lead (me), 1 Visual Designer, 1 Interaction Designer, 1 Content Designer, 1 UX Researcher, 2 PMs, 18+ Engineers
  • Timeline: 3 months from idea to launch
  • Core challenge: Pivot a research-focused product ('Trends') into a generative AI tool to meet the rapidly evolving needs of creators, navigating extreme ambiguity and a highly aggressive timeline.

My role & approach

As UX Design Lead, I drove the strategic vision and roadmap for this Gen AI experience. I fostered a highly collaborative environment, working with visual design, interaction design, content design, and research to deeply understand and iterate with creators. This agile approach allowed us to move swiftly from initial concept to production in a rapid three-month cycle, laying critical foundations for a scalable product.

The challenge

As YouTube creators rapidly adopted GenAI tools in early 2024, we pivoted from the research-focused 'Trends' tab to develop the 'Inspiration' tab, a generative tool designed to support creators' evolving needs.

A shared language for faster product decisions.

01

Idea

A unique take on a potential video.

02

Thumbnails & titles

The visual and verbal promise viewers choose.

03

Outline

The key sections that make the video worth watching.

Explore the experience

No more blank screens

Providing AI-driven inspiration, tailored to each creator's channel, directly addressing a critical pain point in the video creation process.

Explore the experience

See the big picture

Providing a comprehensive 'Video Concept' view to visualize and validate video concepts, including audience interest and key content elements, enabling informed decision-making.

Explore the experience

Brainstorm thumbs

Dedicated spaces for in-depth exploration of thumbnails and titles, allowing creators to experiment and refine their idea until it feels right!

Explore the experience

Brainstorm titles

Dedicated spaces for in-depth exploration of thumbnails and titles, allowing creators to experiment and refine their idea until it feels right!

Inspiration tab in YouTube Studio with ideas for you and the Brainstorm video ideas panel
Video Concept page with outline, titles, thumbnails and related videos (scrolls)
Thumbnails brainstorm screen with generated thumbnail ideas
Titles brainstorm screen with generated title ideas

Impact

This Gen AI experience empowers millions of creators to unlock their full creative potential by facilitating brainstorming. It marked a pivotal shift in how YouTube supports creators' evolving needs.

“The YouTube Inspiration Tab can be one of the craziest hack ever…these outlines are so deep… it's crazy that YouTube will just give you popular topic in your niche and outline keywords to use interest charts”

Creator
Watch the video
Inspiration Tab in YouTube Studio, video thumbnail

Inspiration Tab in YouTube Studio

YouTube Creators

Brainstorm new video ideas, get title and thumbnail suggestions, and more, right inside YouTube Studio.

Watch on YouTube

Little adventures

I don’t always travel, and when I do, I usually forget to write about it. Here is the one time I actually did.

Lilly mountain biking below the Dolomites
Lilly smiling on a rocky summit above an alpine valley
Lilly scrambling along a sharp ridge in the Alps
Transition Sentinel mountain bike in olive
Nordica Enforcer 104 skis
Black Diamond Half Dome helmet
← All trips July 2023 · Norway

8 Days in Lofoten, Norway: First time seeing a sunset at 12 AM

We rented a van and explored Lofoten. Here are a few snaps of some of our favorite moments from this lovely trip.

Lilly and Joe on a cliff above a beach in Lofoten at sunset
Day 1

Tromsø

We arrived in Tromsø, picked up our van from Arctic Campers, loaded up on supplies at Eurospar, and immediately started the drive down to Lofoten. Look at my face in this photo. I look like I just got a puppy.

Day 2

Bunes Beach

We drove down to Reine, which was packed with cars, but we managed to score a great parking spot. From there, we caught a ferry to Kjerkfjord and found the absolute best camping spot in the world. I had the best sleep of my life—turns out, real ocean waves are way better than the ones on the BetterSleep app.

At camp we met a Chilean PhD student who has lived in Italy, Switzerland and now Norway, speaks five languages and once wrote a scout jamboree song in four of them. Nothing like a campsite for hearing someone’s whole story.

Day 3

Horseid Beach

We walked back to the ferry, then did a short hike to set up our next camp. Around 7 PM, we started hiking up the ridge. It was incredibly steep but so much fun. We sat there watching a sunset that lasted until past 11 PM. The colors were so beautiful it was hard to finally pull ourselves away. We eventually hiked back down in full daylight. That ridge was so special, I actually cried a little.

Day 4

Back to Reine!

We took a chill ferry back to Reine and had lunch at Restaurant Gammelbua. The place had so much personality it felt like stepping into a movie. Later that night, we balanced it out with a humble dinner back in the campervan.

Restaurant Gammelbua on Google Maps

Day 5

Værøy

We woke up super early to catch the ferry from Moskenes to Værøy. We drove straight to Håen, hiked up to the ridge, and then spent the afternoon driving around the other side of the island. It was so gorgeous it honestly gave me Greece vibes! Joe ate the world’s strangest-looking waffles on the ferry. He swore they were good, but hey, van food humbles you haha.

Day 6

Driving to Senja

The weather was terrible, so we spent the whole day driving to Senja. The best part about having a van is the strategy: drive when it rains, pull over when it’s sunny, and hike until everything hurts. We parked for the night by the sea at the Hesten trailhead—in a painfully expensive parking lot.

Day 7

Hesten Hike

We woke up at 4 AM to beat the crowds and started the Hesten hike. The weather was perfect, and the climb was surprisingly easy. We reached the peak with only one other couple up there taking pictures. We walked along the ridgeline, snacking on wild blueberries, and didn’t see another soul until our hike down.

Later, we drove to the southern part of Senja and found Senja Roasters, an amazing coffee shop run by expats. We chatted with the Spanish barista and drank some incredible house-made kombucha. We ended the day making burgers by a tunnel overlooking the ocean, then drove down to the beach to wait for the sunset.

Senja Roasters on Google Maps

Day 8

We went home!

Saturday started with terrible weather. We drove to a nearby cafe run by a super friendly Russian-Ukrainian woman. The coffee and pastries weren’t great, but she was wonderful. We spent the rest of the day driving around and ended up at a beach at the end of a fjord, making noodles and rice in the van and accepting that the weather had ruined our plans for a final sunset hike.

We eventually drove back to Tromsø, caught the ferry, and even saw a caribou. Back in civilization, we ate hotdogs, pastries, and some really good pizza. It was an incredible eight days, and then we finally went home!

Eight days from Tromsø to Senja. Tap a photo to see that stop, or zoom in to see where each one was taken.

Barranquilla born.
Zürich based.

Life is hard, so I made it harder by moving to a new country and trying to learn German. I stay sane by spending every free minute outside.

I built this game to bring one of my favorite trails in the Dolomites, the Sella Ronda, to life. Drop in and ride with me.

Sellaronda
00:000 / 30

Nice! 🏆

Now back to work, Lilly.

My approach

Built with empathy

Discovering new products is supposed to be fun. I’m obsessed with the “build to learn” mindset because it forces you to stay curious and open.

In a world where AI is moving faster than ever, the products that win aren’t the ones that ship the most features. They are the ones built with the most empathy.

The future belongs to those who are curious enough to reshape how things are done. Ultimately, what separates us from bots isn’t just intelligence, it’s agency. It’s our messy desire to push new ideas into the world and try something completely new.

I love the messy process of building, learning directly from users, and watching early assumptions evolve into product gems. Doing this alongside brilliant people at Google has sharpened my product thinking. At the end of the day, exposure to the user is everything.

Experience
  • 2025 – NowStaff UX Designer, Prototyping LeadYouTube Creator
  • 2021 – 2025UX Design LeadInspiration Tab Studio
  • 2018 – 2021Interaction DesignerGoogle Drive
  • 2016 – 2018Product DesignerNioLabs
  • 2014 – 2016Lead DesignerNinedot
Beyond design

Always curious

I’ve cracked the code: the best way to stay humble is to actively suck at multiple sports as an adult. Watching a six-year-old fly past me on a trail is the ultimate reminder that learning is the answer.