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A YC Startup Just Beat Claude Code, Cursor, and Gemini at Code Review

The gap between first and second place is bigger than the gap between second and last.

Ruben Dominguez's avatar
Ruben Dominguez
Apr 06, 2026
∙ Paid

Everyone is racing to write code faster.

cubic is racing to review it better.

That turned out to be the smarter bet.

cubic (YC X25) just ranked #1 on Martian’s Code Review Bench, the first independent benchmark built to test AI code reviewers. Against Claude Code, Cursor BugBot, Gemini, and CodeRabbit.

It was a landslide.


The numbers

Bar chart titled "cubic ranks #1 in Martian's Code Review Bench" showing F1 scores for seven AI code review tools. cubic leads at approximately 61% with a white bar significantly taller than all others. The remaining tools in ascending order are Graphite at roughly 16%, Coderabbit at 31%, Gemini at 34%, Claude Code at 37%, Greptile at 41%, and Cursor BugBot at 45%. The gap between cubic and second place is visually larger than the entire gap between second and last place. Source: codereview.withmartian.com
cubic ranks #1 on Martian's independent Code Review Bench. The gap between first and second place is bigger than the gap between second and last. Source: Martian Code Review Bench — codereview.withmartian.com

Why this matters right now

AI coding tools tripled how fast developers write code. The review side stayed the same.

More PRs. Same number of engineers. Bugs slipping through on teams stretched too thin.

Financial Times graphic titled "The past year has seen an explosion in coding productivity" showing year-on-year growth across four indicators from 2022 to 2026: new websites, new iOS apps, GitHub code pushes in the US, and GitHub code pushes in the UK. All four metrics show sharp acceleration from 2024 onward, with new iOS apps reaching above 40% year-on-year growth and GitHub code in the UK and US both showing significant upward spikes in 2025 and 2026. Sources listed as Domain Name Industry Brief, SensorTower, and GitHub. FT graphic by John Burn-Murdoch.
The explosion in coding output is real and accelerating. New websites, new apps, GitHub pushes — all up sharply since 2024. More code being written means more code that needs reviewing. That is the problem cubic was built to solve. Source: Financial Times, John Burn-Murdoch, 2026.

cubic puts specialized AI agents on every pull request automatically. Multiple agents, each with one job, running in sequence. And when a bug is hard to find, cubic runs for 24 hours straight to track it down.

That is what caught 11 critical vulnerabilities in a Cloudflare plugin shipped to a FedRAMP government property. Human review missed all of them.

Guillermo Rauch (Vercel’s CEO) posted about it (72,000 views)

“Another critical vulnerability was disclosed today, in addition to the 10 we reported within the first day, which they shipped to a .gov FedRAMP’d property.”


The traction

▫️ $0 to $1M ARR in under a year

▫️ 250,000+ repositories under review

▫️ Customers: n8n, Granola, Resend, Legora

These are serious engineering teams. They chose cubic.


“If your team is on cubic and your competitors aren’t, that’s an unfair advantage.”

Paul Sanglé-Ferrière, founder and CEO

The benchmark makes that very hard to argue with.


The AI Code Review Playbook: How to Ship Faster Without Shipping More Bugs

The complete workflow for teams using AI to write code. How to structure reviews, what to catch before cubic runs, how to combine AI writing and AI review into a system that actually holds up in production.

Here is exactly what is inside:

  1. AI coding workflow that holds up in production — the exact sequence for going from prompt to merged PR without introducing bugs at speed

  2. PR hygiene rules that make AI review work better — what to do before the AI reviewer runs so the feedback is actually useful

  3. 8 categories of bugs AI-generated code gets wrong most often — with specific examples and how to prompt your way around each one

  4. security checklist for AI-generated code — the vulnerabilities that show up consistently in vibe-coded and LLM-assisted projects, and how to catch them before they ship

  5. prompts that produce more reviewable code — how to write prompts for Claude Code and Cursor that generate code structured for easier review, not just faster output

  6. how to brief cubic for maximum coverage — the setup steps that make the biggest difference in what cubic catches

  7. the team workflow for AI-native engineering teams — how to structure roles, review queues, and escalation paths when AI is writing most of the code

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The AI Code Review Playbook

1. The AI coding workflow that holds up in production

Most teams using AI to write code have the same problem:

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