Mario Joos
About Mario Joos
Mario Joos works as a strategist for large YouTube creators. Press coverage of the Deaku round describes him as the strategist behind many of MrBeast's viral videos.
His LinkedIn profile lists Brightrock as his employer and Sofia, Bulgaria as his location. Earlier posts on the profile describe him as a retention director for some of the largest YouTube channels, who trains creators and their teams to grow their channels. The current headline says he works with some of the biggest creators and creative teams to help them scale.
No public source found describes a company he founded, a fund he runs, or a formal investing career.
The only angel investment found in public sources is Deaku's pre-seed round in March 2026. Reports name him among the creator-investors who took part alongside lead investor Fuel Ventures, Rob Landes, Charles Berthoud and Rob Van Impe. Press coverage describes these participants as creators who understand production workflows first-hand.
His individual cheque size and ownership stake were not disclosed. No earlier angel investments were found.
Deaku is an AI-powered workspace for the creator economy. It combines strategy, analytics, collaboration, communication and AI in one connected platform, and aims to replace the set of separate tools creators use today. The founders are Oscar Ferguson, a former NHS doctor, and Harrison Chapman. The £480K round is meant to fund product development, engineering and support hires, and go-to-market partnerships with creator-economy figures.
This is the only AI investment found for Mario Joos in public sources.
With one public investment, a pattern is hard to establish. That investment is a pre-seed round in an AI tool for creators and creator-led teams, in a round led by a UK investor. Mario Joos has not made public statements about stage, sectors, geography, check size or what he looks for in founders. His professional background is in YouTube audience retention and creator workflows, so creator-economy products are the area where his experience is documented.
- Deaku: AI-powered workspace for creators and creator-led businesses, covering strategy, analytics, collaboration and AI. Pre-seed of £480K led by Fuel Ventures, March 2026.
- fuel.ventures/deaku-closes-480k-pre-seed-round-led-to-replace-fragment
- startupmag.co.uk/funding/deaku-2026-pre-seed-funding
- businesscloud.co.uk/live-blog/creator-economy-startup-deaku-raises-480
- techround.co.uk/?post_type=post&p=147506
- deallite.substack.com/p/uk-tech-investment-news-by-deal-lite-5b0
- linkedin.com/in/mario-joos-52249928
- linkedin.com/posts/mario-joos-52249928_in-the-past-few-months-people-h
Investing activity
Mario Joos appears in 1 AI deal tracked by the Lounge deals desk. The rounds are mostly Pre-seed, with a median round size of $640K. The most recent is Deaku (Pre-seed, £480K, Mar 2026).
Mario Joos most often invests alongside Fuel Ventures, Fuel Ventures has, Rob Van Impe and Rob Landes, and the companies they back on Lounge are mostly in AI.
Deals
Frequently asked questions about Mario Joos
Who is Mario Joos?
Mario Joos is a YouTube strategist who works with large creators. Press describes him as the strategist behind many of MrBeast's viral videos. His LinkedIn profile lists Brightrock and a Sofia, Bulgaria location.
Has Mario Joos invested in AI startups?
Yes. He took part in Deaku's £480K pre-seed round in March 2026. Deaku is an AI-powered workspace for creators. The round was led by Fuel Ventures.
What is Mario Joos's angel check size?
His check size is not public. Reports of the Deaku round give the total raised (£480K) but not individual amounts.
What stage does Mario Joos invest in?
The only public investment found is a pre-seed round. He has not published a stated stage focus.
What sectors would suit a pitch to Mario Joos?
His documented investment is in creator-economy software with AI features, and his professional experience is in YouTube retention and creator workflows. He has not published a thesis, so founders outside this area should treat fit as unconfirmed.
Where can founders find Mario Joos online?
He has a LinkedIn profile, linked on this page. No personal website or X account was found in public sources.
Is Mario Joos an angel investor?
Yes. Mario Joos invests personally as an angel.
What AI companies has Mario Joos invested in?
Mario Joos's AI investments include Deaku. The 1 round on Lounge are listed on this page with amounts, dates and co-investors.
What stage does Mario Joos invest at?
In the rounds tracked on Lounge, Mario Joos has invested at Pre-seed, with a median round of $640K.
Who does Mario Joos co-invest with?
Mario Joos's most frequent co-investors on Lounge are Fuel Ventures (1 deal), Fuel Ventures has (1 deal), Rob Van Impe (1 deal), Rob Landes (1 deal) and Charles Berthoud (1 deal).