Worldbuild Research
Overview
Worldbuild is a thesis-driven venture capital firm founded and managed by Sumeet Singh, formerly a Partner at Andreessen Horowitz (a16z) and Senior Associate at Nyca Partners. The firm describes itself as partnering with "creative technologists" — founders who are building at the frontier of what AI and compute make possible. Worldbuild operates as a solo-GP fund based in New York.
Investment Thesis: The Model Economy
Sumeet Singh's investment framework, which he calls the "Model Economy," is grounded in one core observation: the playbook of the last era of software investing is over. Drawing on Richard Sutton's "bitter lesson" — the idea that scale and compute always beat domain-specific cleverness — Singh argues that most AI startups being built today are fighting a losing battle. Specialist tools that bolt AI onto existing workflows will be absorbed by increasingly capable foundation models over time.
This leads Singh to two investment categories where he believes durable companies can be built:
Path 1: Model Economy Infrastructure — Companies that build what AI models need to grow: compute marketplaces, data infrastructure, energy systems, networking layers, and security. These companies sell to AI labs and infrastructure providers directly. Examples in the portfolio include The San Francisco Compute Company (AI compute marketplace), Aetherflux (space-based solar power for AI data centers), Fractal Power (grid-scale energy infrastructure), and Flower Computer (humanist data and networking infrastructure).
Path 2: Post-Skeuomorphic Applications — Companies that invent entirely new workflows that only become possible because of AI — not digitizing old processes, but discovering genuinely novel ones. These companies leverage multi-agent coordination, large-scale simulation, and continuous learning in ways that would be impossible without modern AI. Portfolio examples include Browserbase (headless browser infrastructure for AI agents), Armory Medical (agentic AI for healthcare operations), and Company Picnic (AI-powered living characters for interactive storytelling).
Worldbuild explicitly avoids companies that simply wrap AI models around existing SaaS workflows — what Singh calls "the specialist trap."
Stage Focus
Worldbuild invests primarily at the pre-seed and seed stages, typically writing one of the first institutional checks into a company. The portfolio reflects very early-stage bets on technical founders before products reach market.
Check Size
Not publicly disclosed. Given the stage focus (pre-seed/seed) and solo-GP structure, typical check sizes are estimated in the $250K–$2M range.
Lead Tendency
Insufficient public data to confirm. Given the early-stage focus and the fact that Singh is often the first institutional investor, it is likely he leads or co-leads rounds.
Portfolio Highlights
- The San Francisco Compute Company (sfcompute.com): AI compute marketplace described as the "Airbnb" of GPU compute. Raised $40M Series A led by DCVC and Wing Venture Capital at $300M valuation.
- Browserbase (browserbase.com): Reliable headless browser infrastructure for AI agents and LLMs. $68M total raised; $40M Series B led by Notable Capital.
- Aetherflux (aetherflux.com): Space-based solar power startup founded by Baiju Bhatt (Robinhood co-founder). $50M Series A in April 2025 co-led by Index Ventures and Interlagos. Reportedly raising Series B at $2B valuation.
- Fractal Power (fractalpower.com): Vertically integrated grid-scale energy company operating on the ERCOT grid in Austin, TX. Raised $7M. Builds, owns, and trades distributed energy assets.
- Armory Medical (armorymedical.com): Applied AI lab building multi-modal orchestration and agentic AI systems to automate healthcare operations for clinics and enterprises.
- Company Picnic (companypicnic.com): Builds AI-powered "Living Characters" with independent cognition and natural interaction. Team has backgrounds from Google, Pixar, Blizzard, and Netflix; award-winning (Oscar, Emmy, Arrow).
- Flower Computer (flowercomputer.com): Building foundational data and networking infrastructure "from first principles" for a world where humans and machines interact naturally.
- Actual Computer (actual.inc): Early-stage; details limited.
- Athanor (athanor.inc): Early-stage; details limited.
- Truffle (itsalltruffles.com): Early-stage developer tools.
- Interfere (interfere.com): Early-stage; website restricted.
Team
Sumeet Singh — Founder and Managing Partner. Previously Partner at Andreessen Horowitz (a16z), where he invested in companies including Sardine (fraud detection, raised at 10x entry valuation at Series C). Prior to a16z, he was Senior Associate at Nyca Partners (fintech-focused VC) and worked at Brigit. Singh writes prolifically about AI infrastructure and the post-software era on his Substack (sumeetsingh.substack.com) and on Every.to.
Investment Philosophy
Sumeet Singh's three-step research process: (1) curate a high-quality information ecosystem through algorithm optimization and primary sources, (2) identify technological catalysts that enable new possibilities, and (3) convert research into conviction by generating hypotheses about which products and business models will emerge. He emphasizes that companies must either build what models need to get better, or invent workflows that only AI makes possible — anything in between is a trap.
Geographic Focus
Primarily US, with concentration in San Francisco Bay Area and New York. Portfolio companies are based in SF (sfcompute, Browserbase), San Carlos CA (Aetherflux), Austin TX (Fractal Power), Brooklyn NY (Flower Computer), and other US cities.
Recent Activity
Worldbuild has been actively investing across AI infrastructure and post-skeuomorphic applications from approximately 2023–2026. Multiple portfolio companies have achieved significant milestones: Browserbase raised $40M Series B (2025), Aetherflux raised $50M Series A (April 2025) and is reportedly raising a $2B valuation Series B (2026), and SF Compute raised $40M Series A.