About AfterQuery

AfterQuery is an applied research lab curating data solutions for foundation model development. We serve every frontier AI lab with the mission of delivering the best data to power the best models. In doing so, we can make expertise that once took a lifetime to build available to anyone who needs it.

Our customers are the ones building the foundation models themselves and our work sits directly in the loop of how those systems improve. This is a rare opportunity to join a company at a defining moment in AI. We are YC's fastest unicorn, valued at $3.2 billion. We're based in San Francisco and backed by leading investors including Altos Ventures, BoxGroup, and Y Combinator and angels from Google DeepMind, OpenAI, Anthropic, Meta Superintelligence Labs, and Microsoft AI.

Why Apply

Massive Opportunity: We are YC's fastest unicorn valued at $3.2 billion and we're not slowing down.

Founding Impact: You will own and architect core infrastructure systems that power our platform from the ground up.

Equity & Growth: Competitive salary and meaningful equity. As we scale, you’ll have the opportunity to shape the engineering organization and lead major technical initiatives.

Strong Team: Our founding team has experience from Citadel Securities, Meta, Google, Silver Lake, and Morgan Stanley — work alongside world-class engineers and researchers.

Overview

As one of our Latin American engineers, you’ll be critical in creating data infrastructure that will be shaping the future development of frontier models. You will get a lot of responsibility, owning entire projects end-to-end – meaning you can see your impact instantly.

Responsibilities

• Design and build scalable systems, focusing on our AfterQuery Experts site

• Collaborate across research, product, and design to ship features quickly without sacrificing quality

• Write clean, maintainable code and contribute to documentation

• Participate in code reviews and design discussions

• Solve real-world scalability and reliability challenges

• Contribute to the core infrastructure powering data and evaluation for the world's leading AI labs

Required Qualifications

• Ideally 5+ years of experience

• Strong coding fundamentals in Node.js and TypeScript, Python, and/or Go

• Deep understanding of distributed systems, scalability challenges, and system design

• Familiarity with cloud platforms such as GCP or AWS, Kubernetes, APIs, and NoSQL databases

• Ability to reason about trade-offs and balance speed versus reliability under pressure

• Active GitHub with real projects demonstrating you are a builder at heart

• Works autonomously and collaboratively without burning out under heavy load

• Proactive, identifies problems and drives solutions without being told to

• High-output and high-accountability mindset, can work banker hours when needed

• Strong bias toward delivering simple solutions to complex problems

• Strong written and verbal communication skills

• Can clearly and compellingly articulate why they want to join a startup and work in AI now

Preferred Qualifications

• Background as a founding engineer at a high-growth startup

• Ex-founder of a technically sophisticated and complex product

• Has trialed or succeeded in past fast-paced startup roles with strong references

Company Benefits (For Eligible Employees):

• Health Insurance: Medical, Vision, Dental

• 401(k) with Employer Match

• Daily Meals: Daily UberEats Stipend

• Monthly Wellness Stipend

• Commute Covered

We are an equal opportunity employer committed to providing a workplace free from discrimination and harassment. Employment decisions are made without regard to legally protected characteristics under applicable federal, state, or local law.

We comply with applicable pay transparency requirements and provide compensation ranges based on the position, qualifications, experience, and other relevant factors. Reasonable accommodations are available to qualified individuals with disabilities and for sincerely held religious beliefs, as required by law. This job description is intended to describe the general nature and level of work performed and is not an exhaustive list of all duties, responsibilities, qualifications, or working conditions associated with the position. We reserve the right to modify this job description as business needs change.