Most ambitious (technically complex) "IH" product / startup

Simply curious - In terms of technical complexity, what is the most ambitious "IH" product / startup you have heard of (or worked on)?

If we look at the VC-funded startups - we see a spectrum of ambitious startups such as the following (but not limited to):

• DeepMind : Solve "AGI"
• Anthropic Ai : "AI safety and research company that’s working to build reliable, interpretable, and steerable AI systems."
• AnyScale: Scaling machine learning algorithms across distributed compute systems
• Improbable (Gaming): Massive/Immersive 3D environments/games
• Rigetti/PsiQuantum: Quantum computing
• Relativity Space: 3D printed rockets / rocket engines / advanced manufacturing
• Anduril: Defense hardware / drones etc
• Rebellion Defense: AI products for defense industry
• Desktop Metal: Advanced manufacturing / 3D printing
• Boom: build supersonic passenger jets
• Mystic Ai, Groq, Cerebras, Graphcore, Kneron, SambaNova: AI acceleration hardware; tensor operation optimized compute
• XTX Markets (UK: FX, sovereign debt) / Binance (Singapore: crypto) / FTX Markets (HK: cyrto) - Not "startups" per se - but market makers that rely on sophisticated technology and mathematical underpinnings to trade FX, sovereign debt, crypto derivatives products and more.

Of course there are many - these are just some that immediately come to mind. That being said, I was curious if any "IH" project/startup either started with similar ambitions OR transitioned into a company with such ambitions?