AI Engineer - Personalization Infrastructure

Details

Perplexity is an AI-powered answer engine founded in December 2022. The company builds accurate, trustworthy AI that powers decision-making and assistive AI. Perplexity serves hundreds of millions of queries per month and is rapidly growing.

In this role you will be an AI Infrastructure Engineer focused on building the next generation of personalization infrastructure: systems that enable the AI to remember contexts, understand user intents, and deliver highly personalized experiences.

Responsibilities

• Architect and ship the next generation of personalization infrastructure: long‑lived LLM memory, long‑context understanding, conversation retrieval, async task execution, and related query retrieval.
• Build event-to-embedding pipelines and feature stores; design vector and hybrid indices; implement retrieval/ranking services that power real‑time, personalized experiences.
• Partner cross‑functionally with Product and Research to translate signals into durable memory and measurable relevance lift; instrument metrics, run A/B experiments, and iterate quickly.
• Drive end‑to‑end ownership: data modeling, schema and contracts, batch/stream processing, model training, deployment, observability, and on‑call for owned services.

Requirements

• Strong programming skills in production systems with hands‑on experience across data, serving, and infra layers.
• Proven experience building large‑scale retrieval and indexing infrastructure (vector/hybrid search, inverted indexes).
• Deep familiarity with LLM‑centric IR: RAG architectures, semantic retrieval, prompt/context optimization, and long‑context strategies.
• Experience building and deploying ML for personalization: retrieval/ranking models, feature engineering, offline evaluation, and online experimentation (A/B, interleaving).
• Ownership mindset, bias to action, and ability to deliver in fast‑moving, ambiguous environments.
• 4+ years of industry experience in distributed systems, search/recommendation, or ML systems. Experience with LLM memory or conversation retrieval is a strong plus.

Compensation

• Cash compensation range: $200,000 - $280,000 (final offer amounts depend on experience and other factors).
• Equity may be part of the total compensation package.

Benefits

• Comprehensive health, dental, and vision insurance for you and your dependents.
• Includes a 401(k) plan.