Senior iOS SDK Engineer

About the Role We are looking for a Senior iOS SDK Engineer to join our Mobile Observability team, responsible for designing, building, and maintaining our open-source Swift SDK across Apple platforms (iOS, tvOS, watchOS, and macOS). This is a hands-on, SDK-first role focused on building high-performance instrumentation libraries embedded in customer applications. It is ideal for someone who enjoys working close to the platform, solving difficult edge cases, and designing APIs that other developers rely on. You’ll work on performance monitoring, telemetry capture, hang detection and crash reporting, all designed for minimal overhead and maximum reliability. You’ll collaborate across platform teams and contribute to evolving observability standards such as OpenTelemetry. What You’ll Do Design, build, and maintain a modular Swift SDK used by developers across Apple platforms Work on crash reporting, hang detection, performance monitoring, and telemetry instrumentation Build reliable mechanisms for offline storage, batching, retries, and data delivery under mobile runtime constraints Contribute to SDK architecture, API ergonomics, and backward compatibility Design and evolve APIs with a focus on stability, clarity, and long-term compatibility Debug complex issues across devices, OS versions, and app environments, including threading, memory, and lifecycle challenges Develop and maintain capture services for networking, user interactions, and system events, leveraging frameworks such as MetricKit Optimize startup performance, binary size footprint, memory usage, and thread safety Coordinate with cross-platform SDK teams (React Native, Flutter, Unity) to ensure native SDK changes do not introduce downstream breaking issues Collaborate on OpenTelemetry alignment and upstream contributions Partner with Product and Customer Success to incorporate developer feedback Basic Qualifications Strong proficiency in Swift, including async/await, structured concurrency, and protocol-oriented design Experience building or maintaining SDKs, frameworks, or developer-facing libraries Deep understanding of Apple platform runtime constraints: memory, threading, lifecycle, startup performance Experience debugging issues in production mobile environments Familiarity with API design, versioning, and SDK evolution Understanding of binary compatibility and ABI stability Strong advocate for testing, reliability, and code quality Excellent verbal and written communication skills Experience using Git and modern CI/CD workflows Openness to AI-augmented engineering workflows Preferred Qualifications Experience with Objective-C interoperability, runtime behavior, or method swizzling Experience with Swift macros or Swift Syntax Familiarity with OpenTelemetry or observability concepts (traces, spans, logs) Experience supporting multiple Apple platforms from a shared codebase Familiarity with system-level frameworks such as MetricKit or MXDiagnostic Experience working in a multi-SDK ecosystem where platform changes affect cross-platform consumers Contributions to open-source projects Experience supporting external developers / SDK users Additional Expectations Interview & Collaboration Our interview process includes live, synchronous conversations. Final stages may include an in-person meeting with a team member (travel may be required). Engineering Workflow Evolution We work in an environment where AI-assisted tools are increasingly part of engineering workflows. We value pragmatic, thoughtful use of these tools and expect candidates to be comfortable discussing their experience and perspective. Role Focus This role emphasizes SDK / framework / platform engineering, not application UI development. Work Culture & Travel We are a remote-first company. This role is open to candidates located anywhere in the U.S. or Canada. We believe in regular in-person connection and expect travel for team off-sites and collaboration to be approximately once per quarter. The cash