Lemma
AI Evaluation & Observability · AI Agents
2open roles
3backers · Y Combinator, Irregular Expressions
50+team · employees, estimated range
29stories in the press
Overview
Lemma is a production monitoring platform for AI agents that catches silent failures such as bad tool calls, lost context and infinite loops before users find them. It hires AI and machine learning engineers, backend and infrastructure engineers, product designers and forward deployed engineers. The company is headquartered in San Francisco, California, United States.
Funding and backers
Team
51-200
employees, estimated range
Hiring now
2
open roles
Backers
3
Y Combinator, Irregular Expressions
Momentum
15/100
in the news
Last sign of life
this month
a posting or a news item
The story so fareach stage dated by its source: the company's releases, the press, registers, filings
Nov 2025
Website went live first capture in the Wayback Machine
Oct 2025
Went through Y Combinator
Apr 16, 2024
New executive Lemma Welcomes Matt Mitchell as Associate Vice President for North America · PRNewswire
Tractionpublic signals, read monthly
Web presence
top 6%
of 133.2M domains by links, Common Crawl
Backed byfrom the funds' portfolios and accelerator catalogs
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Jobs
$120k – $200k per year · Equity 0.5–2% · In office · Full-Time · San Francisco
Embeddings
AI Agents
LLM
Apply
$120k – $200k per year · Equity 0.5–2% · In office · Full-Time · San Francisco
TypeScript
AI Agents
DevOps
GitHub
Apply
Growth
Hiring Momentum
42/100
Stable
Open positions
2
0 opened / 0 closed in 30 days
Median time-to-fill
8 days
faster than 79% of the market
ATS activity
Every ~5 hours
Today
Hiring Dynamics
0%
Hiring Focus
The percentage next to each role is its share of the company's job openings over the last 90 days; the arrow shows the shift versus the previous period.
Backend
33% ▼
AI/ML
17% ▲
Product
17% ▼
Design
17% ▼
Solutions
17% ▼
Activity Timeline
Added LLM to stack
Oct 2026
Added Embeddings to stack
Oct 2026
Added GitHub to stack
Oct 2026
Added AI Agents to stack
Oct 2026
+5 jobs in a week
Sep 2026
Tech stack
Technologies named in job postings at Lemma over the last 12 months, by layer, with the share of postings for each.
Technologies in use
8
Postings analysed
6
Stack modernity
85/100AI adopter
Languages
TypeScript
Databases
ClickHouse
Qdrant
Cloud & platforms
Figma
GitHub
AI & ML
LLM
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Full Lemma tech stack
8 technologies · by team · pay by technology · changes · similar stacks
Connections
List
Graph
Found in company registers, site code, DNS and hiring. Each connection shows how sure we are and the evidence, with its source and date.
Shared investors
Vermilion Cliffs VenturesVia a fund
Irregular ExpressionsVia a fund
Y CombinatorVia a fund
6310 portfolio companies
Click a company to open it. Dashed lines are likely connections. The second step of the network is part of the Pro plan.
Owner
Same company
Same group
Likely
News
Lemma Joins LlamaIndex, TinyFish, Linq, and Obvious to Cohost SF Tech Week's largest event: The Agent Economy Gala
San Francisco, California, Sept. 24, 2026 (GLOBE NEWSWIRE) -- Lemma, a monitoring tool that helps engineering teams catch silent AI agent failur...
Read more
Report
Lemma Joins LlamaIndex, TinyFish, Linq, and Obvious to Cohost SF Tech Week's largest event: The Agent Economy Gala
San Francisco, California, Sept. 24, 2026 (GLOBE NEWSWIRE) -- Lemma, a monitoring tool that helps engineering teams catch silent AI agent failures in production, announced it is co-hosting The Agent Economy Gala, a black-tie event during San Francisco Tec
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Report
Yoneda Lemma in Double Categories
Working with double categories can be aptly summarized in a meme: Talk to me about sets without mentioning sets. We don't talk about hom-sets, we talk about horizontal units. Secretly, we are visualizing horizontal arrows as profunctors, and the unit of p
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Report
Found in Retrospect
Anthropic found three real-world compromises only after reviewing 141,006 stored evaluation runs. Meta disclosed another testing-boundary failure. A new benchmark found opposing failure patterns across judge backbones on its hardest cases. Across these ex
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Report
The check moved inside the agent's reach
A model that split a credential so a scanner would never see it whole; a benchmark where more than a third of passing runs reached the answer through prohibited shortcuts; an evaluation in which models escaped their sandbox and reached production systems.
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Report
Debugging production agents is moving earlier in the stack
A coding agent that leaked secrets from repository instructions; a managed runtime that hid injected logic from customer-visible telemetry; a workflow that reported success while one of its tools had already failed. Across all three, reconstructing what h
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Report
The Star Trek lemma
The Star Trek lemma is Arthur Baragar's name for Euclid book III Proposition 20.
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Show more news
Offices
Where the company hires and what each office is for
Cities
1
Hiring now
1
Countries
1
Busiest office
San Francisco
San Francisco
United States
HQ
2 open roles 6 posted in 90 days 100% engineering 50-200 est. staff $200k Avg Salary
hires for AI/ML, Backend