AfterQuery — Senior Software Engineer, Infrastructure​/Platform

After Query — Senior Software Engineer, Infrastructure/Platform

Type: Full-time | On-site | San Francisco, CA Compensation: $250,000–$350,000 + competitive equity Hiring count: 2 Visa sponsorship: None available Reports to: TBD (screening interviewers named: Alec, Carlos)

Design and build the core infrastructure powering After Query's data generation, evaluation, and agentic systems — the shared platforms that let engineers and researchers run large-scale human-in-the-loop workflows, evaluation harnesses, and automated data pipelines used to train frontier AI models. A highly technical role with broad ownership, working directly with the founding team.

• Architect and develop the shared infrastructure powering data generation platforms, human-in-the-loop systems, and evaluation pipelines
• Build systems capable of processing large-scale datasets and high-throughput workloads with strong reliability guarantees
• Create reusable infrastructure and APIs that let product engineers and researchers build quickly and reliably on top of core systems
• Design systems with strong observability, monitoring, and fault tolerance for production workloads at scale
• Help define long‑term system architecture across data pipelines, compute infrastructure, task orchestration, and storage systems
• Work closely with engineers and researchers to support new AI experimentation workflows and platform capabilities
• Define standards for system design, deployment, reliability, and infrastructure operations

Tech stack: Python and/or JavaScript (Node.js/Next.js); GCP or AWS; message queues / event‑driven systems (Kafka, RabbitMQ, Pub/Sub)

• 5+ years building and owning production distributed systems or platform infrastructure
• Strong backend proficiency in Python and/or JavaScript (Node.js/Next.js)
• Cloud infrastructure experience in GCP or AWS
• Message queues and event‑driven systems (Kafka, RabbitMQ, Pub/Sub)
• High‑throughput data pipelines and asynchronous processing
• System scalability, performance, and reliability ownership
• Shared infrastructure, APIs, and internal platform development
• Observability, monitoring, and fault tolerance design
• Long‑term architecture ownership across data pipelines, compute, and storage
• Cross‑functional collaboration with engineering and research teams
• Undergraduate degree from the U.S., Canada, or the U.K.

• Background at FAANG, Jane Street, Citadel, Stripe, Ramp, or top‑tier YC company
• Has architected and owned production infrastructure end‑to‑end at scale
• Experience building internal developer platforms or shared infrastructure at senior level
• Experience with AI infrastructure, LLM evaluation systems, or ML pipelines
• Has scaled early infrastructure at a high‑growth startup
• Experience designing human‑in‑the‑loop or workflow orchestration systems
• Defined architecture decisions and set engineering standards, not just executed them

• Only mid‑level or IC contributor experience with no architectural ownership
• Background exclusively at large legacy enterprises or slow‑moving companies
• Has never owned a production system end‑to‑end
• No cloud infrastructure depth in GCP or AWS
• No experience with high‑throughput or distributed systems
• Under 5 years of experience

Salary $250,000–$350,000 Equity Competitive / meaningful (Series A) On‑site policy On‑site, San Francisco Visa sponsorship None available

Employment type

Full‑time Location San Francisco, CA Hiring count 2

• None provided on the role page.