Backend Software Dev Engineer II - Yahoo Mail, AntiSpam

About US

Yahoo Mail is the ultimate consumer inbox with hundreds of millions of users. It's the best way to access your email and stay organized from a computer, phone or tablet. With its beautiful design and lightning fast speed, Yahoo Mail makes reading, organizing, and sending emails easier than ever.

Yahoo Mail Anti Spam Engineering:
The Yahoo Mail Anti Spam team develops and maintains high-performing systems that reliably protect our users from spam, phishing, fraud, and abuse with advanced ML/AI algorithms. These systems require extreme reliability, resilience, and performance. We are tackling some of the toughest challenges in architecture design, algorithm development, and data engineering, and there are innumerable opportunities to innovate across all of these areas.

Yahoo Mail Delivery Engineering:
The Yahoo Mail Delivery team develops and maintains high-performing systems that reliably deliver billions of messages a day to users and the wider Internet. The system requires extreme reliability, resilience, and performance. It is the critical infrastructure that transfers messages across systems, and the team works on problems spanning web services, email RFCs, and networking layers.

As a global email provider, Yahoo Mail is the ultimate consumer inbox, serving more than 220 million users. It is the best way to access your email and stay organized from a computer, phone, or tablet. We handle billions of inbound connections per day and manage trillions of messages that require petabytes of efficient storage. Come join this team of engineers, product managers, and designers building next-generation experiences that transform how people connect every day.

We are also in the middle of a major modernization effort, moving toward cloud-native infrastructure to improve scale, reliability, and automation. We are also an AI-forward team, actively deepening how we use agentic AI in our daily engineering. It is an exciting time to contribute.

This role sits on the Anti Spam and Delivery team, where you will help build the systems that detect spam and abuse and deliver billions of messages a day. At IC3, what you need to accomplish is clear; how to accomplish it often is not. You will work under minimal guidance, make decisions independently, review code and give constructive feedback, and create technical designs with simplicity in mind.

• Build and operate distributed systems for inbound protection, entity reputation, traffic shaping, and message delivery.
• Use AI-assisted development tools as part of your daily workflow, validating and refining what they produce rather than accepting it blindly.
• Translate defined technical requirements into correct, readable, testable code, and deploy continuously to production.
• Troubleshoot software failures and tune performance across high-throughput services.
• Design and simplify existing components under minimal guidance.
• Review peers' code, give constructive feedback, and help with estimation.

• BS/MS in Computer Science or a related field, with a strong grasp of fundamentals: data structures, algorithms, operating systems, and networking.
• Proficiency with AI-assisted development tools such as Claude, Git Hub Copilot, Cursor, or Codex, with sound judgment over correctness, security, and maintainability.
• 3+ years of backend-focused software development experience in Java, Go, or C++ (we are primarily a Java team, with some systems in Go).
• Solid understanding of cloud computing concepts:
  IaaS, PaaS, and SaaS.
• Machine learning knowledge with some hands-on AI coding experience.
• Experience with a public cloud (GCP or AWS).
• Experience with containers (Docker) and orchestration (Kubernetes), preferably on GCP.
• Experience designing and building high-performing, complex server applications on Unix/Linux.
• Strong troubleshooting and debugging skills, including performance tuning.
• A clear communicator who enjoys helping people and stays constructive under pressure.

• Strong understanding of network programming and client/server architecture.
• Familiarity with best practices for cloud security, scalability, and performance optimization.
• Professional experience with high-availability, high-throughput distributed systems.
• Experience with big data technologies such as Hadoop, HBase, and Spark.
• Experience in algorithm design and ML/AI.
• Experience with queuing and streaming technologies such as Kafka or Apache Storm.
• Experience with databases such as PostgreSQL.
• Working knowledge of a scripting language such as Python, Perl, or Ruby.
• Knowledge of Scrum and Agile methodologies.

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

At Yahoo, we offer flexible hybrid work options that our employees…