Principal Engineer

It takes powerful technology to connect our brands and partners with an audience of hundreds of millions of people. Whether you’re looking to write mobile app code, engineer the servers behind our massive ad tech stacks, or develop algorithms to help us process trillions of data points a day, what you do here will have a huge impact on our business—and the world.

About Us

The Consumer Data’s Foundations & AI Platform Engineering team builds the foundational intelligence layer powering Yahoo's global ecosystem, processing over 100 PB of data daily for more than a billion users. We combine large-scale distributed data systems, enterprise knowledge and metadata, and modern AI to transform how data is discovered, understood, trusted, governed, and operated across the company.

Our mission is to build the intelligence and reasoning layer over Yahoo's enterprise data ecosystem—connecting metadata, lineage, operational telemetry, business context, and governance signals so teams can understand what is happening across complex data systems and take action with confidence.

About the Role

We are seeking a Principal Engineer (IC5) to lead the architecture and development of AI-powered data intelligence platforms operating at Yahoo scale.

This role sits at the intersection of large-scale distributed data systems, enterprise knowledge, Retrieval-Augmented Generation (RAG), and agentic AI. You will define how AI reasons over Yahoo's data ecosystem to help teams detect anomalies, diagnose incidents, understand dependencies, discover trusted data, optimize infrastructure, and automate complex operational workflows.

As a Principal Engineer, you will establish technical direction and reference architectures for enterprise AI systems while building reusable platform capabilities that can be adopted across engineering, analytics, governance, and business organizations.

You will also help shape how Yahoo engineers use AI to build software—leveraging AI-assisted development, evaluation, and automation to accelerate engineering while maintaining rigorous standards for correctness, reliability, security, and operational safety.

What you'll build

Systems that answer questions like:

• Why did engagement decline after last week's deployment?

• What breaks downstream if we change this schema?

• What's the root cause of this data quality incident?

• Which datasets should I trust for this decision?

• Where can we cut capacity waste without slowing consumer queries?

Delivered through natural language interfaces over enterprise metadata and operational telemetry, serving executives, data producers, data consumers, and governance teams.

Responsibilities

• Define technical vision and architecture for Yahoo's AI-powered data intelligence platform.

• Architect petabyte-scale batch and streaming systems with Beam, Dataflow, Spark, and Kafka.

• Build production RAG and multi-agent systems: semantic metadata integration, agent orchestration.

• Establish evaluation frameworks — retrieval quality, agent accuracy, hallucination rate, operational safety — with automated benchmarking, so we ship AI we can trust.

• Use AI development tools to accelerate design, implement the bar for how the org validates AI-generated code and agent plans.

• Drive adoption of RAG and agentic patterns across engineers.

• Partner with product, governance, infrastructure, and exit-form priorities.

Basic Qualifications

• 10+ years building distributed systems and large-scale data platforms, or equivalent experience.

• Degree in CS, AI/ML, Engineering, Math, or related field,

• Deep Python expertise and strong software engineering fun

• Production experience with batch and streaming processing (Kafka, or equivalent).

• Shipped and operated RAG applications in production; search, and reranking.

• Track record evaluating and validating AI-generated code correctness and operational safety.

• Strong communication and technical leadership across cross-functional stakeholders.

Preferred Qualifications

• Agentic AI frameworks (LangGraph, CrewAI, AutoGen, Semant)

• GCP: Vertex AI, Gemini, BigQuery, Vector Search, Dataflow

• Enterprise metadata, lineage, governance, or observability

• Knowledge graphs and semantic reasoning systems.

• Daily use of AI pair-programming tools (Claude, Copilot, g workflows).

• Led large technical initiatives influencing strategy across multiple teams.

The material job duties and responsibilities of this role include those listed above as well as adhering to Yahoopolicies;exercising sound judgment;working effectively, safely and inclusively with others;exhibiting trustworthinessandmeeting expectations;and safeguarding business operations and brand integrity.

At Yahoo, we offer flexible hybrid work options that our employees love! While most roles don’t require regular office attendance, you may occasionally be asked to attend in-person events or team sessions. You’ll always get notice to make arrangements. Your recruiter will let you know if a specific job requires regular attendance at a Yahoo office or facility. If you have any questions about how this applies to the role, just ask the recruiter!

Yahoo is proud to be an equal opportunity workplace. All qualified applicants will receive consideration for employment without regard to, and will not be discriminated against based on age, race, gender, color, religion, national origin, sexual orientation, gender identity, veteran status, disability or any other protected category. Yahoo will consider for employment qualified applicants with criminal histories in a manner consistent with applicable law. Yahoo is dedicated to providing an accessible environment for all candidates during the application process and for employees during their employment. If you need accessibility assistance and/or a reasonable accommodation due to a disability, please submit a request via the Accommodation Request Form (www.yahooinc.com/careers/contact-us.html) or call +1.866.772.3182. Requests and calls received for non-disability related issues, such as following up on an application, will not receive a response.

We believe that a diverse and inclusive workplace strengthens Yahoo and deepens our relationships. When you support everyone to be their best selves, they spark discovery, innovation and creativity. Among other efforts, our 11 employee resource groups (ERGs) enhance a culture of belonging with programs, events and fellowship that help educate, support and create a workplace where all feel welcome.

The compensation for this position ranges from $143,625.00 - $299,375.00/yr and will vary depending on factors such as your location, skills and experience.The compensation package may also include incentive compensation opportunities in the form of discretionary annual bonus or commissions. Our comprehensive benefits include healthcare, a great 401k, backup childcare, education stipends and much (much) more.

Currently work for Yahoo? Please apply on our internal career site.