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

Joël Hainzl

Cofounder of Action Layer, Palo Alto. From Graz.

LinkedIn X GitHub

hainzljoel[at]gmail[dot]com

2026. Now: applied AI, Palo Alto

Action Layer, cofounder.

Enterprise AI, in stealth, with Fabian Hildesheim in Palo Alto. Incorporated August 2026.

Scout for Andreessen Horowitz.

Since March 2026, alongside Action Layer.

Co-author: a 9B model that beat Claude Fable 5 on one task.

A Fermisense study with Fabian Hildesheim and three others: trained with RL on one ecommerce listing task, 87% vs 77% of the achievable score, $0.50 instead of $34 per 1,000 listings.

The study

2025 to 2026. The house and the fellows

The Outpost, cofounder.

An AI hacker house in Barron Park, Palo Alto, open since February 2026: 70+ fellows through it across residencies, dinners and working sessions in the first five months, with an a16z grant behind it.

70+ fellows in the first five months

@JoelHainzl

Palo Alto, 2026

Fellows at long white desks under chandeliers in the main hall of the AI hacker house in Palo Alto, whiteboards on the stage, 2026
6 Aug 2026 860 likes Palo Alto, 2026 on X

Frontier Fellows, cofounder.

A network for technical founders at the AI frontier, started out of The Outpost in 2026: I run selection and programming.

frontier-fellows.com

Won a car in Warsaw.

December 2025, with team AIWINTER at the ElevenLabs x Project Europe hackathon: the basedspace partner prize was a Volkswagen Jetta.

Joël Hainzl, second from left, with his four teammates holding the car shaped prize board at the ElevenLabs hackathon in Warsaw, December 2025
Photo: Alicja Kozak

The post

2024 to 2026. Munich: both sides of the table

First product hire at BEO.

Co-Power (BEO), a Cherry Ventures backed battery company in Munich, August to November 2025: product work on its entry into licensed electricity supply.

Fortino Capital, first analyst on the new DACH team.

November 2024 to January 2025 in Munich: sourcing, diligence and IC materials, 120+ founder conversations in eleven weeks.

120+ founders in eleven weeks

Entrepreneur in Residence at Tacto.

July to October 2024 at the Sequoia and Index backed procurement company in Munich: ran the weekly customer webinar (500+ attendees in total) and revenue operations for a nine person sales team.

Joël Hainzl, right, in glasses and a light blue shirt, taking a selfie with a Tacto colleague among packed shipping boxes in the Tacto office in Munich, 2024

TUM and CDTM.

Master's studies in Finance and Information Management at TUM, 2024 to 2026, and the CDTM Class of Spring 2025, the joint TUM and LMU entrepreneurship program.

CDTM

2020 to 2023. WU Vienna and San Francisco

Sixth person at Dex (YC S19), San Francisco.

Growth and business development from January to April 2023: channel tests, onboarding conversion and ten YouTube creator deals.

Joël Hainzl, left, with Dex founder and CEO Kevin Sun in front of the Salesforce Tower, San Francisco, 2023

Dex on YC

2nd of 2,961 at WU Vienna.

BSc Business Administration, 2020 to 2023: finished a semester early, Rector's List three times, fall 2022 on exchange at USC Marshall.

2017 to 2020. Photography

Photographer.

A one year diploma at the Fotoakademie Graz, then freelance fashion, portrait and event work in Graz, Vienna, New York, Milan and London, and some modeling on the other side of the camera.

Joël Hainzl with long hair in a bun walking down a cobbled street next to a woman in a feather coat, black and white street photo from his modeling years

Fotoakademie Graz

Selected work.

Nine frames: runways, street style and portraits from Graz, New York, Milan and London.

  • Runway finale at an evening outdoor fashion show, a long line of models in leather and shearling coats walking toward the camera
  • 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
  • Young man in aviator glasses and an orange hoodie against an orange wall, head turned over his shoulder, studio portrait
  • Models walking a runway at a fashion show, the lead model in a long printed gown with teased hair, more looks following behind her
  • Black and white studio portrait of a young man in a pinstripe shirt, finger resting on his nose, looking off to the side
  • 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
  • Model in wide floral trousers, a brown half blazer and a floral blouse, hands on hips, lit against a blue wall with her shadow behind her
  • Blonde model in narrow black sunglasses and sheer tulle sleeves, lit in pink and yellow against a dark background
  • Woman in a long white skirt and dark top standing on a mound at sunset, palm trees silhouetted against a golden sky

Studio assistant at Big Sky Studios, London.

August 2019 to August 2020, on the production crews of the shoots booked into the studio.

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 on a stand, 2019

bigskylondon.com

43 orders in a day.

Riding for Velofood in Graz and hosting as an Airbnb Superhost paid for the photography years: the previous delivery record was 28.

43 vs 28 orders in a day, new record vs old

2003 to 2017. Music and dance, Graz

It started on the street.

From the age of six I played violin in the streets and arcades of Graz with my family.

Joël Hainzl, about eight years old with curly blond hair, playing violin in a shopping arcade in Graz, bicycles and a Gerry Weber shop behind him

Violin, piano, harp and hackbrett.

Three first prizes at prima la musica 2008, Austria's youth music competition (Styrian round), and the course for highly gifted students in violin at the Graz music university, KUG.

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

Opened the Opernredoute.

I danced in the opening committee of the Graz opera house ball.

Opening of the Opernredoute ball in the Graz Opera house, debutante pairs crossing the parquet under the chandeliers, Joël Hainzl at the front left