AfterQuery

Software Engineer - Platform/Applied AI (Fullstack)

Reposted 19 Hours Ago

San Francisco, CA, USA

In-Office

180K-220K Annually

Senior level

Artificial Intelligence • Big Data

The Role

Design and build full‑stack data capture workflows (Next.js web, Python desktop), architect high‑throughput data pipelines with low latency, collaborate on product strategy, ship features rapidly, and establish engineering best practices for team growth.

Summary Generated by Built In

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. Since raising our $30M Series A at a $300M valuation, AfterQuery has grown well over a $100M revenue run rate.

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 one of the fastest-growing YC companies in our batch, and we believe we can become one of the fastest-growing YC companies of all time.
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 core engineers, you’ll be critical in creating data infrastructure that will be shaping the future development of frontier models. You will be one of our first hires, and will get a lot of responsibility, owning entire projects end-to-end – meaning you can see your impact instantly.

Responsibilities

Build and scale complex data capturing workflows across web (Next.js) and desktop (Python)

Architect and optimize data pipelines that experience high throughput, with heavy loads

Collaborate with the founding team to define product strategy and ship features fast.

Set engineering best practices and lay the groundwork for future team growth.

Required Qualifications

Proficiency in JavaScript (Next.js) and Python, with demonstrated experience building full-stack web applications

Experience with serverless architecture and cloud functions for implementing heavy data processing (GCP/AWS)

Storage, caching & search: Hands‑on with Redis (caching), Elasticsearch (indexing), and message queues (Kafka/RabbitMQ) to build scalable, low‑latency pipelines.

Experience getting your ideas into production (founder experience preferred)

Preferred Qualifications

Background in AI research, LLM evaluations, or human‑in‑the‑loop systems

Skills Required

Proficiency in JavaScript (Next.js) and Python, with experience building full‑stack web applications
Experience with serverless architecture and cloud functions for heavy data processing (GCP/AWS)
Hands‑on experience with Redis (caching), Elasticsearch (indexing), and message queues (Kafka/RabbitMQ) to build scalable, low‑latency pipelines
Background in AI research, LLM evaluation, or human‑in‑the‑loop systems
Experience getting ideas into production
Founder experience

AfterQuery Compensation & Benefits Highlights

The following summarizes recurring compensation and benefits themes identified from responses generated by popular LLMs to common candidate questions about AfterQuery and has not been reviewed or approved by AfterQuery.

Fair & Transparent Compensation — Pay is considered attractive when work is accepted, with public role postings and materials indicating strong compensation across expert projects and core employee roles. The experts track also highlights transparent pay rates and approval-linked payouts that do land.
Healthcare Strength — Employee materials indicate medical, vision, and dental insurance are provided. Job postings reference a comprehensive package consistent with standard coverage.
Wellbeing & Lifestyle Benefits — Daily meal stipends, commute support via Uber credits, and a monthly wellness stipend (including gym membership coverage) are prominently advertised. These lifestyle perks suggest attention to day-to-day convenience and wellbeing.