Joël Hainzl, black and white headshot, smiling in clear round glasses and a black crew neck sweater

Joël Hainzl

LinkedInX

Fellows working at long white desks under chandeliers in a large hall in Palo Alto, 2026

View on X

01

Started Frontier Fellows supported by a16z in Palo Alto, 2026 @JoelHainzl 859 likes

Chart of cost per 1,000 listings against task score: a fine tuned Qwen3.5 9B model with GRPO reaches 87% at $0.50, ahead of Gemini 3.1 Pro, GPT 5.6 sol, GPT 5.5, Claude Fable 5 and GPT 5.5 pro at 70 to 76% for $19 to $172
02

Coauthored study by finetuning 9B model beat Claude Fable 5 at 1/68th the cost

Joël Hainzl, center in a black turtleneck, with his team holding a drawn car board and the VW Jetta key on stage at Project ElevenLabs in Warsaw
03

Won a car, VW Jetta, in Warsaw at Project ElevenLabs

CDTM Class of Spring 2025 group photo, around thirty students in navy CDTM shirts in front of a wooden chapel
04

Accepted into CDTM, Class of Spring 2025

Joël Hainzl, right, taking a selfie with a Tacto colleague in the Tacto office
05

Entrepreneur in Residence at Tacto, backed by Sequoia Capital and Index Ventures

Joël Hainzl, right, with three fellow winners in front of the MindsDB stage wall at the MindsDB hackathon in San Francisco
06

Won the MindsDB x OpenBB FinTech AI Hackathon in San Francisco

Joël Hainzl with arms crossed in a white t shirt in an atrium at WU Vienna
07

Ranked 1st of 2,961 at WU Vienna, finished a year early, 3x Dean's List

Joël Hainzl with long hair standing in a white cyclorama studio at Big Sky Studios in London beneath a large softbox and an HMI lamp
Dua Lipa Future Nostalgia album cover: Dua Lipa in a pink shirt and white gloves at the wheel of a car, a full moon behind her
Perfect magazine cover: Kate Moss in a black turtleneck, black and white portrait under the pink Perfect masthead
Studio 01 at Big Sky Studios London, a large white infinity cove under a lighting rig
08

Worked on set at Big Sky, London's biggest photo studio along side clients such Dua Lipa, Max Verstappen, Naomi Campbell, etc.

Joël Hainzl with long hair in a camel coat, studio portrait published on PhotoVogue, Vogue Italia, with the Vogue watermark
Joël Hainzl with long hair in a fur trapper hat and a long camel coat, portrait published on PhotoVogue, Vogue Italia, with the Vogue watermark
09

Modelled for Vogue Italia

Aigner runway finale, a long line of models in leather and shearling coats walking toward the camera
Front row at a fashion show in London with Anna Wintour in dark glasses
10

Worked at fashion weeks in London and Milan

Dancer in a black leotard balancing on one leg on a brick wall at dusk, the London skyline with the Shard and Tower Bridge behind her
Josipa, London, 2019
Young man in aviator glasses and an orange hoodie against an orange wall, head turned over his shoulder, studio portrait
Jose, Graz, 2018
Models walking a runway at a fashion show, the lead model in a long printed gown with teased hair
Irina Shayk x Moschino, Milano, 2019
Black and white studio portrait of a young man in a pinstripe shirt, finger resting on his nose, looking off to the side
Jose friend, Graz, 2018
Two women in street style looks on a city plaza, one in gold with cat eye sunglasses, the other in a pink wig and a long blue coat
Space Outfit, New York, 2018
Model in wide floral trousers, a brown half blazer and a floral blouse, hands on hips, lit against a blue wall
Luisa #1, London, 2019
Blonde model in narrow black sunglasses and sheer tulle sleeves, lit in pink and yellow against a dark background
Luisa #2, London, 2019
Woman in a long mint green skirt and a dark strapless top standing on a mound at sunset, palm trees silhouetted against a golden sky
Safae, Morocco, 2019
11

Selected photography work 2018 to 2019

Joël Hainzl's orange road bike with the velofood.at delivery box on the rack, against a green wall
12

Financed my education as a bike courier, breaking the daily delivery record by 43%, often riding +100km per day, while it was raining or snowing

Joël Hainzl as a boy playing violin in front of a grand piano, his hackbrett and its hammers in the foreground, newspaper photo
13

Started studying at university at age 10 & won music competitions in four separate categories: violin, piano, harp and hackbrett

A blond child with braided hair playing the violin in a street arcade, bicycles and shop fronts behind
A mother holding a CD and three blond children in front of a tourist information center, a harp at the left edge
14

Didn’t grow up in permanent home until 6, travelled around playing music with my family on the street

01 / 14