Simone Luna Louise Söderlund Giertz (/jɛtʃ/ YETCH; Swedish: [jæʈʂ]; born 1 November 1990) is a Swedish inventor, maker, robotics enthusiast, TV host, and professional YouTuber. She has also previously worked in MMA sports journalism, and as an editor for Sweden's official website .
Giertz has named the Disney cartoon character Gyro Gearloose as one of her earliest inspirations. She studied engineering physics in college but dropped out after a year, going on to study at Hyper Island in Stockholm, and took an interest in programming and robotics. Giertz's interest in electronics began in 2013; she made a toothbrush helmet for a children's show pilot episode on electronics, which was uploaded to YouTube after not being picked up, starting her YouTube career.
Giertz brands herself as "the queen of shitty robots" and runs a YouTube channel where she employs deadpan humor to demonstrate mechanical robots of her own creation to automate everyday tasks; despite working from a purely mechanical standpoint, they often fall short of practical usefulness, for comic effect. Giertz's creations have included an alarm clock that slaps the user, a lipstick applier, and one that shampoos the user's hair. When building her robots, Giertz does not aim to make something useful, instead coming up with excessive solutions to potentially automatable situations.
In 2016, Giertz joined Tested.com, collaborating with Adam Savage on her first project, the Popcorn Feeding Helmet. In 2017, she hosted the comedy TV show Manick with Nisse Hallberg on Swedish TV6. The basic premise of the show is that the hosts invent funny creative solutions to everyday problems.
Family and personal life
As of July 2016, Giertz lives in San Francisco.
The Giertz family surname is of Low German origin. She is the daughter of Caroline Giertz, novelist and TV host, who Giertz describes as a "ghostbuster" due to her mother's work on paranormal reality TV show Det Okända. Giertz is a descendant of Ericsson founder Lars Magnus Ericsson.  Lutheran theologian and bishop Bo Giertz was her great-great-uncle.
At the age of 16, Giertz spent a year in China as an exchange student. She stayed in Hefei, where she learned basic Mandarin. During her stay in China she also made a cameo appearance on a Chinese sitcom called Huan Xi Long Xia Dang (Chinese: 欢喜龙虾档, the Happy Lobster Restaurant), where she played Catherine, a Canadian girl who married a Chinese man. 
Giertz also briefly attended the Swedish Royal Institute of Technology (KTH), studying Physics.
In 2018 she was diagnosed with a benign brain tumor.