Hillclimb C Verified
RL environment company · Math
- Domains
- Math
- On X
- @hillclimbai ↗
- Funding
- Y Combinator F25 · rounds and investors
- Tier
- C why
- Snapshot
What Hillclimb does
Hillclimb builds and sells RL environments and aggregated human research data to frontier labs to improve models' AI research capabilities.
- Sells
- RL environments and Data
- Leads with
- Science
- Based in
- San Francisco, USA
- Team
- 1-10
- Website
- hillclimb.com ↗
What Hillclimb sells
Read from Hillclimb's own website, checked October 11, 2026: the line that puts it in each category.
RL environments
“To further scale these ambitions, we sell the environments we make to frontier labs.”
hillclimb.com ↗
Data
“Aggregating all human research data”
hillclimb.com ↗
Domains Hillclimb covers
Science leads with
“If you'd like your models to be better at AI research, email us at”
hillclimb.com ↗“we deployed a similar approach for math, fostering a dedicated community of IMO medalists”
hillclimb.com ↗
Hillclimb competitors and alternatives
The companies that sell the most of the same things in the same domains, and what they share with Hillclimb.
- dmodel Also sells RL environments · also in science
- ReasonCore Also sells RL environments and human data · also in science and math
- Turing Also sells human data and RL environments · also in science and math
- Ulam Also sells RL environments and human data · also in math and science
- Mercor Also sells human data and RL environments · also in science
Tier C
Early: a small team.
How much stands behind a tier: usage, who backs it, a confirmed line from its own site or paper, and a clear read on X. High with three of the four, medium with two, low otherwise.
- team 1-10
- investors: Amjad Masad, Jeff Dean, Paul Graham
- went through Y Combinator Fall 2025
- in curated RL directories (3 pts)
How we got to tier C
- Adoption: team 1-10; investors: Amjad Masad, Jeff Dean, Paul Graham; went through Y Combinator Fall 2025. Tier C.
- On X: unclear, none buzz No move.
- In curated RL directories: 3 points, a floor of none.
- Confirmed: a line from its own site or paper places it.
A clear view on X moves a tier one step up or down; most entries don't move. How tiers work.
Hillclimb funding
- Accelerator
- Y Combinator F25
Backed byY Combinator Fall 2025
Accelerator
- Y Combinator Fall 2025
- Y Combinator's company directory lists hillclimb with the website hillclimb.com, in its Fall 2025 batch
- Checkable on YC's page: ycombinator.com/companies/hillclimb
- 5 pages read also name Y Combinator
Angels 3
- Amjad Masad
We're backed by Tier 1 VCs, Jeff Dean, Paul Graham, Amjad Masad
- Read: “We're backed by Tier 1 VCs, Jeff Dean, Paul Graham, Amjad Masad”
- Found word for word on its own site: hillclimb.com
- No other page or directory names it yet
- Jeff Dean
We're backed by Tier 1 VCs, Jeff Dean, Paul Graham, Amjad Masad
- Read: “We're backed by Tier 1 VCs, Jeff Dean, Paul Graham, Amjad Masad”
- Found word for word on its own site: hillclimb.com
- No other page or directory names it yet
- Paul Graham
We're backed by Tier 1 VCs, Jeff Dean, Paul Graham, Amjad Masad
- Read: “We're backed by Tier 1 VCs, Jeff Dean, Paul Graham, Amjad Masad”
- Found word for word on its own site: hillclimb.com
- No other page or directory names it yet
Every figure is quoted from its own site, its accelerator or a funding announcement; a round's amount and lead appear only when its quote states them. Startup databases are never used as evidence. Checked 2026-10-11. How funding is checked.
Where Hillclimb sits
Its domain on the map, live. Hover a logo for its name; click to open it. Open it on the full map
Latest from Hillclimb on X
@hillclimbai ↗Next: browse all environments. Entry from the RL Research daily scrape of public sources, 2026-11-05 snapshot.