Performance Engineer, Backend

Responsibilities:

• Identifying and eliminating backend performance bottlenecks by profiling PHP applications, analyzing MySQL/MariaDB query performance, and optimizing Memcached usage across Automattic’s products.
• Building and improving performance observability—developing dashboards, instrumentation, and automated detection that surface regressions before they reach production, and give engineering teams clear, actionable data.
• Partnering with product and platform engineers to review code and architecture through a performance lens, advocating for efficient database access patterns, caching strategies, and backend design decisions.
• Raising the performance bar across engineering by documenting best practices, contributing to internal guidelines for PHP and database performance, and mentoring teams on how to write backend code that scales.
• Proactively searching out performance issues and working to resolve them.
• Deep dives on individual sites, working alongside support staff and engineers to address customer performance issues.

Requirements:

• Deep hands-on experience with PHP performance: you can profile a PHP application, identify hot paths, and reason about memory usage and execution time at the code level.
• Strong understanding of caching layers and strategies: you know how to design and debug Memcached (or similar) caching patterns, understand cache invalidation trade-offs, and can reason about when and where caching helps versus hides problems.
• Experience doing performance work at scale: you’ve worked on systems serving millions of requests where small inefficiencies compound into real problems, and you understand the difference between optimizing on a benchmark and optimizing under production load.
• Ability to instrument, measure, and prove: you don’t guess, you measure. You have experience building or using profiling tools, APM systems, and performance dashboards to turn hunches into data and verify that a fix actually worked.
• Excellent written communication skills: Automattic is a distributed, async-first company. You’ll need to clearly explain complex performance findings, write up proposals, and influence engineering decisions through writing, not meetings.
• Self-direction and ownership: you can identify the highest-impact performance work, prioritize it, drive it to completion, and hold yourself accountable without waiting for someone to assign it to you.
• Bonus points for hands-on experience with WordPress and WooCommerce in high-traffic production environments