Staff Fullstack Software Engineer, Core Performance in United States at Jobgether

This position is posted by Jobgether on behalf of a partner company. We are currently looking for a Staff Fullstack Software Engineer, Core Performance in United States.

This is a high-impact, staff-level engineering role focused on one of the most critical and visible challenges in consumer software: performance across all user-facing surfaces.
You will own and define the discipline of performance engineering across web, mobile, and desktop experiences, ensuring millions of users experience fast, reliable product interactions.
The role begins with deep hands-on work on high-traffic web applications, then expands into cross-platform leadership across iOS, Android, and desktop systems.
You will operate at the intersection of frontend, backend, measurement systems, and product analytics to identify and resolve system-wide bottlenecks.
This position requires strong technical leadership to set performance standards, build measurement systems, and drive cross-org alignment.
You will also play a key role in shaping AI-assisted engineering workflows to improve productivity and engineering velocity across teams.
This is a rare opportunity to define a new engineering function with direct impact on user experience at massive global scale.

Own and drive end-to-end performance improvements across consumer-facing surfaces, starting with web and expanding across mobile and desktop platforms.

• Profile and optimize high-traffic web applications, including React-based surfaces, using tools such as flame graphs, heat maps, and RUM data.
• Identify and execute high-impact performance improvements, ensuring measurable gains in user experience and system efficiency.
• Define and implement performance measurement frameworks, instrumentation, and regression detection systems across engineering teams.
• Lead cross-platform performance strategy across iOS, Android, and desktop in collaboration with platform engineering teams.
• Write and ship production code in JavaScript/React, with additional backend contributions in Python and Go.
• Establish performance engineering standards and mentor senior engineers on best practices in profiling and system optimization.
• Drive cross-functional alignment with engineering, product, and design teams to prioritize performance as a core product metric.
• Apply AI tools to accelerate debugging, optimization, and engineering workflows while scaling best practices across teams.
• Influence architectural decisions and long-term technical direction across Core Engineering.

Requirements:
The ideal candidate is a deeply experienced engineer with a strong track record of improving large-scale consumer application performance and leading cross-org technical initiatives.

• 12+ years of software engineering experience, including at least 3+ years in a senior or staff-level role.
• Strong hands-on expertise in web performance optimization, particularly in JavaScript and React applications.
• Proven experience using profiling tools such as flame graphs, traces, heat maps, and RUM telemetry to drive improvements.
• Experience building or improving production systems in Python or Go supporting user-facing applications.
• Demonstrated ability to lead cross-functional technical initiatives spanning multiple teams and platforms.
• Experience working on consumer-facing products with direct impact on user experience metrics.
• Strong communication skills with the ability to influence technical direction across organizations.
• Experience leveraging AI tools to accelerate engineering workflows and improve system performance.
• Nice to have: experience with iOS (Swift), Android (Kotlin), desktop applications, CI/CD regression systems, or observability pipelines.

Benefits:

• Competitive compensation based on US zone: $198,600 – $335,800 USD depending on location and experience
• Equity participation with long-term value creation potential
• Fully remote-friendly environment with distributed team culture
• Comprehensive health, dental, and vision insurance coverage
• Flexible time off and strong work-life balance policies
• Home office support and productivity stipends
• Paid parental leave and family support programs
• Annual learning and development budget
• High-impact staff-level role with strong visibility to senior leadership
• Opportunity to define a new engineering discipline at scale