As a Principal Engineer on our Advertising, Company Intelligence, and Intent team, you'll help design and implement the core systems that power our real-time marketing platform. From high-throughput ad infrastructure to large-scale identity resolution and intelligent systems enhanced by LLMs, push the boundaries of scale, intelligence, and speed-and deliver real-world business impact. You'll be joining a team with a broad range of ambitious, technically deep projects-from APIs that process tens of billions of events per day, to new buyer intent algorithms powered by LLMs, to a unified B2B identity graph. Depending on your strengths and interests, you'll be matched to the initiatives where you can have the greatest impact. This is a high-growth, high-ownership environment operating at the edge of what's possible in modern software engineering, data infrastructure, and applied AI. What you will do * Design and build distributed systems that process, enrich, and respond to billions of behavioral events per day in real time * Develop high-performance APIs and services that support advertising, identity, and intent features across the Marketing Platform * Leverage machine learning and large language models (LLMs) to analyze behavioral data, classify content, extract signals, and enable intelligent decision-making * Build intelligent agents using frameworks like LangGraph or MCP to reason over data and power user-facing insights * Design and operate data pipelines using tools like Kafka, Kinesis, and ClickHouse to support both streaming and batch workloads * Drive quality, performance, scalability, and observability across all systems you own * Collaborate cross-functionally with product managers, data scientists, and engineers to deliver customer-facing features and internal tooling * Contribute to technical leadership and mentorship, especially if operating at the Principal level. What you will bring: * 5+ years of backend, data, or infrastructure engineering experience (Senior); 8+ years (Principal), or equivalent impact and leadership. Strong experience in at least one of the following: * Distributed systems engineering (e.g., building low latency high and throughput APIs, scalable microservices, event processing pipelines) * Big data infrastructure (e.g., streaming, warehousing, low-latency storage at scale) * Applied AI/ML, including use of LLMs for extraction, classification, or reasoning tasks. * Proficiency in one or more core languages: Java, Go, Python * Solid grasp of SQL and large-scale data modeling * Familiarity with databases and tools such as: ClickHouse, DynamoDB, Bigtable, Memcached, Kafka, Kinesis, Firehose, Airflow, Snowflake AI Native development mindset: * Comfortable using LLMs as part of your development workflow-whether via tools like Copilot, Cursor, ChatGPT, Claude, or others-to boost productivity, explore architecture ideas, and rapidly prototype. * Skilled at designing and implementing LLM-powered systems such as RAG pipelines, agent frameworks (e.g., LangGraph), or intelligent workflows that reason across large datasets in real time. Bonus Points: * Experience in ad tech, real-time bidding (RTB), or programmatic systems * Background in identity resolution, attribution, or behavioral analytics at scale * Contributions to open source in ML, infrastructure, or data tooling * Strong product instincts and a passion for building tools that drive meaningful outcomes #LI-SK #LI-Hybrid