Software Engineer ($300k-$400k + Equity) at high-growth frontier AI startup

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers.

She will pick the best candidates from Jack's network.

The next step is to speak to Jack.

Job Title

Software Engineer

Salary

$300k-$400k \+ Equity \+ Bonus

Company Description

High-growth frontier AI startup

Job Description

You will help build the foundational infrastructure for the next generation of AI. This role involves developing the core product, specifically the complex environments and evaluation frameworks required for training and testing frontier coding agents. Your work will directly impact how advanced AI models are benchmarked and deployed in real-world scenarios.

Location

San Francisco, USA

Why this role is remarkable

• Work at the absolute bleeding edge of AI agent development and frontier model evaluation.
• Join a well-funded team backed by top-tier VCs with significant capital and resources.
• High-impact, early-stage role offering massive ownership and a highly lucrative compensation package.

What You Will Do

• Design and implement robust environments for training and testing autonomous coding agents.
• Build scalable evaluation frameworks to measure the performance and safety of frontier models.
• Collaborate with research and engineering teams to iterate on core product features and infrastructure.

The ideal candidate

• Extensive experience in software engineering with a focus on infrastructure or backend systems.
• Strong understanding of the AI landscape, particularly regarding LLMs and agentic workflows.
• Proven ability to thrive in a fast-paced, high-stakes environment with a focus on shipping quality code.

Who are Jack \& Jill?

Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.

And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.

Next steps

Step 1\. Visit the job listing.

Step 2\. Click

'Talk to Jack'

, or go straight there: https://www.jackandjill.ai/jobs/software-engineer-300k-400k-equity-at-high-growth-frontier-ai-startup-29410fbc-ec4a-476c-8d18-ca06118f186c?utm_source\=linkedin\&utm_medium\=job_post\&utm_campaign\=featured_role_29410fbc-ec4a-476c-8d18-ca06118f186c

Step 3\. Talk to Jack so he can understand your experience and ambitions.

Step 4\. Jack will make sure Jill (the AI agent working for the company) considers you for this role.

Step 5\. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction.

Step 6\. If not, Jack will find you excellent alternatives. All for free.

We never post fake jobs

This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network.

Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description.

We appreciate this can make them look a bit suspect, but there isn't much we can do about it.

Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.