About the Role
Automattic is hiring a Performance Engineer to join our dedicated team focused on making WordPress faster for the over 800 million websites that rely on it worldwide. In this role, you will be responsible for identifying, measuring, and eliminating performance bottlenecks across the WordPress stack, from PHP execution and database queries to front-end rendering and asset delivery. Your work will directly impact the experience of hundreds of millions of users who visit WordPress-powered sites every day.
As a Performance Engineer at Automattic, you will work at the intersection of WordPress Core development and large-scale infrastructure optimization. You will collaborate closely with the Core Performance Team, contributing patches and enhancements that improve load times, reduce server resource consumption, and help WordPress sites achieve excellent Core Web Vitals scores. This is not a role where you optimize a single application - you will be optimizing a platform that powers over 40% of the web, which means every millisecond you shave off matters at an unprecedented scale.
The ideal candidate combines deep PHP expertise with a thorough understanding of modern web performance principles. You should be equally comfortable profiling a complex database query in MySQL as you are analyzing a Largest Contentful Paint waterfall in Chrome DevTools. We are looking for someone who is data-driven, methodical, and passionate about making the web faster for everyone.
Responsibilities
- Profile and optimize WordPress Core PHP code using tools such as Xdebug, Blackfire, and XHProf to identify and resolve CPU and memory bottlenecks in critical execution paths
- Analyze and optimize MySQL database queries, including identifying slow queries, designing efficient indexes, and refactoring schema patterns to reduce query execution time and lock contention
- Design and implement caching strategies at multiple levels of the stack, including object caching (Redis/Memcached), page caching, fragment caching, and browser caching policies
- Monitor and improve Core Web Vitals metrics (LCP, INP, CLS) across WordPress Core and default themes by optimizing critical rendering paths, reducing JavaScript execution time, and implementing resource hints
- Build and maintain automated performance benchmarking infrastructure that tracks regressions across WordPress releases, including CI/CD integration for pull request performance gates
- Contribute performance-related patches to WordPress Core through the official Trac workflow, including writing unit tests and performance tests for all changes
- Investigate and resolve performance issues reported by WordPress VIP clients running high-traffic sites (10M+ monthly pageviews)
- Author technical blog posts and documentation about performance best practices for the broader WordPress developer community
- Evaluate and recommend server-side optimizations including PHP OPcache tuning, PHP-FPM pool configuration, and MySQL query cache settings
- Collaborate with the Gutenberg team to ensure editor performance remains fast as new features are added, including monitoring block rendering times and editor initialization benchmarks
Requirements
- 6+ years of software engineering experience with at least 3 years focused specifically on performance engineering, optimization, or site reliability
- Expert-level PHP proficiency (PHP 8.0+) with deep understanding of PHP internals, OPcache behavior, memory management, and the PHP execution lifecycle
- Strong MySQL/MariaDB expertise including query optimization, EXPLAIN plan analysis, index design, and understanding of InnoDB storage engine internals
- Hands-on experience with profiling tools such as Xdebug, Blackfire, XHProf, or Tideways for server-side analysis, and Chrome DevTools, Lighthouse, and WebPageTest for client-side analysis
- Deep understanding of HTTP caching mechanisms, CDN architecture, and reverse proxy configurations (Varnish, Nginx FastCGI cache)
- Experience with Core Web Vitals optimization and Google's web performance metrics ecosystem
- Familiarity with the WordPress codebase, plugin architecture, and hook system (actions and filters)
- Strong analytical skills with the ability to design performance experiments, collect meaningful metrics, and present data-driven recommendations
- Experience with version control (Git) and collaborative development workflows including code review
Nice to Have
- Prior contributions to WordPress Core, particularly in the performance or database components
- Experience with large-scale WordPress hosting environments (WordPress VIP, Pantheon, WP Engine, or similar)
- Knowledge of server-level performance tools such as perf, strace, or eBPF for low-level system profiling
- Experience with load testing tools such as k6, Locust, or Apache JMeter for simulating high-traffic scenarios
- Familiarity with the WordPress Performance Team's existing projects including the Performance Lab plugin and server-timing headers initiative
- Understanding of image optimization techniques, including modern formats (WebP, AVIF) and responsive image strategies
Benefits
- Competitive salary range of $140,000 - $175,000 USD annually, commensurate with experience and expertise
- Fully distributed company with no offices - work from anywhere in the world
- Open vacation policy with a minimum of 25 days encouraged per year
- Home office setup allowance of $3,000 and ongoing equipment refresh budget
- Professional development budget of $3,500 per year for conferences, courses, and training
- Comprehensive health, dental, and vision coverage (US) or international health insurance stipend
- Company-sponsored sabbatical program: one month paid leave after every five years of service
- Annual company-wide Grand Meetup and regular team meetups in locations around the world
- 401(k) plan with company match (US employees) or equivalent retirement benefits
- Parental leave: 6 months fully paid for primary caregivers, 6 weeks for secondary caregivers
How to Apply
To apply, please submit your resume and a cover letter describing a significant performance optimization you have delivered in a previous role. We are especially interested in hearing about your methodology - how you identified the bottleneck, measured the impact, implemented the fix, and verified the improvement. If you have open-source contributions, blog posts about performance, or publicly available benchmark results, please include links. All applications are reviewed by the engineering team, and we aim to complete the first round of interviews within three weeks of your submission.