Staff Fullstack Software Engineer, Core Performance

Role Description As a Staff Software Engineer at Dropbox, you'll be the singular technical owner of application performance across the Core org — the part of Dropbox that owns every consumer-facing surface: web, iOS, Android, and desktop. This is one of the company's most visible, cross-cutting technical challenges. Your mandate is to make Dropbox feel fast on every surface our customers use.

You'll operate at the intersection of measurement, engineering, and product impact, owning ambiguous problems that span the entire stack and translate directly into business outcomes for hundreds of millions of users. There is no existing performance team at Dropbox — you'll define the discipline. You'll start with the web, profiling our highest-traffic React surfaces, producing flame graphs and heat maps, identifying the most valuable opportunities, and driving fixes through to shipped, measured wins.

The web is your initial focus and the surface where you'll be most hands-on. From there, you'll lead the performance initiative across iOS, Android, and desktop by partnering with the internal platform experts who own those clients — coordinating strategy, transferring measurement practices, and driving the work, rather than building everything yourself. You'll also work across the Python and Go backend services that all of these surfaces depend on, since perceived performance rarely lives in one layer.

Your influence will extend across Core Engineering. You'll define the measurement standards, regression-detection systems, and performance practices that other engineers rely on. You'll also be expected to use AI fluently in your own engineering work and to lead the optimization of AI-assisted workflows across Core, raising the productivity of every engineer around you.

You'll bring clarity where there is uncertainty, raise the bar for engineering excellence through hands-on leadership, and shape how Dropbox thinks about performance for years to come. In return, you'll gain meaningful exposure to senior leadership, build foundational systems that unlock future product capabilities, and grow into an org-level technical strategist — helping advance Dropbox's mission to create a more enlightened way of working. Our Engineering Career Framework is viewable by anyone outside the company and describes what’s expected for our engineers at each of our career levels.

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Responsibilities

Drive performance improvement on the Dropbox web application as the first focus of the role — profiling React surfaces, producing flame graphs and heat maps, identifying the highest-impact opportunities, and shipping measurable improvements Lead the performance initiative across iOS, Android, and desktop by coordinating with internal platform experts who own those clients — setting strategy, defining measurement standards, and driving execution rather than implementing every fix personally Take performance improvements end-to-end: from measurement, to root-cause analysis, to shipped code changes, to validation in production telemetry Build and own the measurement, instrumentation, and regression-detection systems that engineering teams across Core depend on to ship performant code Write production code regularly — primarily JavaScript and React on the web, with backend work in Python and Go on the services those surfaces depend on Set engineering standards for performance work across Core Engineering, and mentor IC3 and IC4 engineers on profiling, measurement methodology, and performance-aware system design Apply AI tooling to performance work and lead the optimization of AI-assisted engineering workflows across Core, raising engineering throughput and shaping how Dropbox engineers use AI to ship better software faster Influence cross-org roadmaps and architectural decisions, partnering with engineering leaders, PMs, and designers to ensure performance is treated as a first-class product attribute Many teams at Dropbo