Mesmer

The operating system for the 100x Engineering Team

3.5Score#245 of 999 agents#11 of 40 in Software engineer

Why it ranks #245

Mesmer, an AI software engineer from YC Sp25, ranks #245 of 999 AI agents and #11 of 40 in Software engineer, with a score of 3.5 of 10. Data as of 3 Oct 2026.

The score adds four parts, each 0 to 10, by weight. Every point comes from public evidence. How scoring works ·

Proof 4 × 30% 1.2
Scale 3 × 30% 0.9
Momentum 2 × 25% 0.5
Autonomy 6 × 15% 0.9
= 3.5

Proof
Do customers use it? 30% of the score
4
Claims a customer result and a customer count.
- +2
  A customer result
  “Hundreds of engineering teams have used Mesmer to 2x their productivity in the first quarter using our platform.”
  YC page
- +2
  A customer count
  “We’re already live with 10+ companies worth over $3B and have reviewed over 70M lines of code along the way.”
  Launch YC post · 14 May 2025
Not found: revenue or growth (+4), named customers (+3), work done at scale (+2)
Scale
Is there a real company behind it? 30% of the score
3
7 people.
- +3
  7 people on its YC page5 to 9 people
Not found: funding round in its news (+3)
Momentum
Is it shipping and growing now? 25% of the score
2
Shows hiring.
- +2
  Hiring: 1 open roleFounding EngineerYC page
Not found: launch YC post in the last 6 months (+3), new traction claim in the last 6 months (+2), funding news in the last year (+2), a batch in the last year (it is YC Spring 2025) (+1)
Autonomy
How much of the job does it do on its own? 15% of the score
6
Supervised agent: takes actions in other systems; a person approves key steps.
- +6
  Level 2 of 4: Supervised agentTakes actions in other systems; a person approves key steps.
What the model read
- Acts in other systems: 63% likely
- Finishes whole tasks: 30% likely
- Calls itself an agent: 97% likely
Level 2: Takes actions in other systems; a person approves key steps.

About Mesmer

Mesmer is the operating system for agentic engineering teams.

A few engineering teams are accelerating at breakneck speed, while most are stuck with incremental gains. Mesmer exists so that gap doesn't come down to who gets lucky with their AI experiments.

We help founders and CTOs turn agents into real leverage across their organization: faster delivery, better quality, less bureaucracy, and a clear view of where the bottlenecks are and what to do next.

Hundreds of engineering teams have used Mesmer to >2x their productivity in the first quarter using our platform.

We are a team of repeat founders and CTOs with 15+ years of experience, including leading engineering together at Origin Financial ($400M), the AI financial advisor founded by Mesmer's CEO.