LilianGuevara

Selected work

Three projects, from a first-of-its-kind sun care molecule to a track program. Each one is science turned into something people use.

Add images/pavise.jpg
(Pavise products)

Image: Pavise

Pavise

Co-founder and formulator, Pavise (subsidiary of B.A.I. Biosciences), 2021–2022

A first-of-its-kind molecule, taken from the lab to a full sun care line.

Result: sold at 1,200+ locations nationwide. The flagship SPF is the product in a peer-reviewed study and was covered by WWD. It won 2024 beauty awards from Cosmopolitan, Harper's Bazaar and Byrdie.

Read the full story

The challenge

B.A.I. had developed DiamondCore®, a patent-protected, diamond-augmented zinc oxide designed to eradicate 80% of damaging reactive oxygen species (ROS). It needed to become finished products that feel good on all skin tones and hold up in real use.

What I did

• Co-founded Pavise and formulated all 7 SKUs around DiamondCore®
• Designed efficacy, dosage and compatibility experiments, including testing that supported the patent application
• Led clinical and consumer testing, including sweat resistance and cosmetic performance across diverse skin tones
• Presented roadmaps and results to executives and investors

Why it matters for sport

Athletes sweat, train outdoors and need protection that stays put. I've taken a new material from the lab to market and tested how it performs under sweat, the same work behind performance materials in footwear and apparel.

Add images/diagnostics.jpg
(device or app, if allowed)

AI hair and scalp diagnostics

R&D Chemist, John Paul Mitchell Systems, 2017–2021, and R&D Consultant, FitSkin, 2026–present

Teaching a device to see what an expert sees, then recommend what to use.

Result: the platform I helped start as the first salon pilot is now used by major beauty brands to recommend products and regimens.

Read the full story

The challenge

Professionals wanted to recommend products based on what the science says a customer's hair and scalp need. The device works as a magnifying glass, enhancing the work of hair professionals.

What I did

• Led R&D for Paul Mitchell's first AI hair and scalp diagnostic program, the first salon brand to pilot the device
• Built the classification framework and recommendation logic that connected scan results to products
• Today at FitSkin, I build classification matrices and annotate image data that train the device's machine learning models

Why it matters for sport

Sports brands increasingly personalize with data: gait analysis, fit scans, wearables. I know how to turn expert judgment into data a model can learn from, and data into a recommendation a person trusts.

Add images/summer-of-fast.jpg
(track session)

Summer of Fast

Founder, LTF Track Club, 2023

A 10-week sprint and speed program for adult runners, on a real track.

Result: a core group of about 10 athletes showed up at 6:30am every week for 10 weeks, forming a community of adult sprinters.

Read the full story

The challenge

Most adult run clubs focused on distance. Runners who wanted sprint speed work had almost nowhere to go.

What I did

• Designed a 10-week sprint and speed program
• Coached weekly 6:30am track sessions in Austin, TX

Why it matters for sport

I design programs, test them with real athletes and learn what keeps people coming back. It's the same loop behind athlete insights, wear testing and community programs.

Running and community

Add images/running-1.jpg
(Pegasus relay, Greece)

Add images/running-2.jpg
(TRE panel)

Add images/running-3.jpg
(coaching or Hood to Coast)

• 2024Nike Pegasus 41 launch relay, Greece. Selected as 1 of 41 runners worldwide; featured on Nike's Instagram.
• 2024The Running Event. Hosted a women's event, interviewed pro athletes and spoke on a panel with an Olympian and a Nike coach.
• 2024, 2025Hood to Coast captain. Built and led Nike-sponsored relay teams; 3rd among Nike teams in 2025.
• 2025Nike After Dark Tour. Paced the 2:20 half-marathon group at the inaugural race.
• 2025–nowRun coach. USATF Level 1 certified since 2019. Coached 5 first-time marathoners, with a 100% finish rate so far, including London and Chicago, and one runner nearly an hour faster in his second marathon. Now coaching 3 for the 2026 Chicago and New York City marathons.
• 2020–2021GIRLAB and The Speed Project. Co-captain and strength coach for 40 women training for The Speed Project, the Los Angeles to Las Vegas relay. Raced it in 2021.
• 2018–nowMarathoner. 8 marathons, including the Boston, Chicago and New York City World Marathon Majors. 3x Boston Marathon qualifier (best 3:15), self-coached.