<p data-pm-slice="0 0 []"><strong>Type:</strong> Contract, per-project.<br><strong>Location:</strong> Remote - alignment with North America is preferred (ideally Pacific Time, acceptable PT-ET).<br><strong>Availability:</strong> Contractor (40 hours per week)</p><p>We’re looking for a highly capable Software Engineer to join our Powered team and help build the core libraries behind every Speedtest client, as well as the SDKs used by device manufacturers and third-party application developers worldwide.</p><p>You’ll work on low-level networking features, platform-specific implementations and cross-platform SDKs that directly impact how millions of users measure and understand their Internet performance.</p><h3>What you’ll do</h3><ul><li><p>Design and build core SDK and library features used by Speedtest clients and third-party partners</p></li><li><p>Develop network testing functionality using Kotlin and Kotlin Multiplatform</p></li><li><p>Build and maintain performance-critical components using C++</p></li><li><p>Maintain and support legacy SDK products built in Java</p></li><li><p>Design clean, well-structured and easy-to-use APIs for both SDK and application use</p></li><li><p>Work close to Android platforms, device hardware and, in some cases, embedded environments</p></li><li><p>Ensure high levels of reliability, flexibility, portability and code reuse</p></li><li><p>Implement analytics and telemetry to monitor performance and behavior in production</p></li><li><p>Write unit, integration, load and stress tests</p></li><li><p>Debug and troubleshoot complex, multi-layer and multi-platform issues</p></li><li><p>Collaborate on architecture and technical decisions across SDK, frontend, backend and distributed server teams</p></li><li><p>Contribute to documentation, developer support and long-term maintenance of SDKs</p></li><li><p>Participate in code reviews and continuous improvement of engineering practices</p></li></ul><h3>What we’re looking for</h3><ul><li><p>5+ years of professional software development experience</p></li><li><p>3+ years of professional Android development experience</p></li><li><p>Strong proficiency in Kotlin and Java</p></li><li><p>Solid knowledge of data structures, algorithms and design patterns</p></li><li><p>Hands-on experience building and maintaining SDKs or reusable libraries</p></li><li><p>Strong understanding of Android Framework and Android SDK development</p></li><li><p>Experience with threading, concurrency and performance optimization on Android</p></li><li><p>Experience with networking frameworks such as OkHttp and TCP sockets</p></li><li><p>Strong understanding of networking fundamentals (IP, TCP/UDP, HTTP/S, WebSockets)</p></li><li><p>Experience designing cross-platform libraries (Kotlin Multiplatform or similar)</p></li><li><p>Experience writing unit, integration, load and stress tests</p></li><li><p>Strong debugging and troubleshooting skills</p></li><li><p>Experience working with Git-based workflows (branches, pull requests, code reviews)</p></li><li><p>Experience with CI/CD pipelines</p></li><li><p>Ability to ramp up quickly on new projects and complex codebases</p></li><li><p>Strong communication and collaboration skills in distributed teams</p></li><li><p>High level of ownership, autonomy and time-management skills</p></li></ul><h3>Nice to have</h3><ul><li><p>Experience with C++</p></li><li><p>Experience with Swift</p></li><li><p>Experience contributing to open-source projects</p></li><li><p>Previous experience working with embedded or hardware-adjacent environments</p></li></ul><p> </p><p>(*) SOUTHWORKS only hires individuals from countries that are not blocked or sanctioned by the United States, including those identified on the <a href="https://home.treasury.gov/policy-issues/financial-sanctions/specially-designated-nationals-and-blocked-persons-list-sdn-human-readable-lists" data-type="LINK" data-url="https://home.treasury.gov/policy-issues/financial-sanctions/specially-designated-nationals-and-blocked-persons-list-sdn-human-readable-lists">United States Office of Foreign Asset Control (OFAC).</a></p>