> Markdown version of [/jobs/ext/2064277-senior-software-engineer-ios](https://www.wearedevelopers.com/jobs/ext/2064277-senior-software-engineer-ios). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Senior Software Engineer - Ios - **Company:** Ziff Davis - **Location:** Madrid, Spain - **Salary:** €50,000.0 - €63,700.0 - **Contract:** Permanent contract - **Skills:** Java (Programming Language), Application Programming Interfaces (APIs), Artificial Intelligence, Data Analysis, Android Software Development, Apple IOS, C++ (Programming Language), Cyber Security, Data Structures, Software Debugging, Software Design Patterns, DevOps, Python (Programming Language), Networking Basics, Software Engineering, SQL Databases, WebSocket, Swift (Programming Language), Kotlin, Objective C++, Multiplatform, Mobile Data - **Published:** August 15, 2026 - **Apply:** https://www.buscojobs.com.es/senior-software-engineer-ios-en-madrid-ID-367433395 ## About the Role Description We are looking for a highly capable Senior iOS Engineer to join our Powered team and take ownership of our iOS SDKs: the CQoE SDK, which telecom carriers and partners embed directly into their own apps to passively measure real-world network quality, and the Speedtest SDK, the core measurement library that powers every Speedtest client., 5+ years of software development experience, with a solid foundation in data structures, algorithms, and design patterns Experience with iOS using Swift Substantial experience building and maintaining SDKs or libraries Strong data literacy: comfortable writing SQL to investigate production and measurement data, using Python (or similar) for analysis, and applying data-quality monitoring practices to catch anomalies before they reach partners A curious, proactive stance toward AI and modern engineering practices Excellent debugging, troubleshooting, data analysis skills Strong time management skills and a self-driven work ethic Nice to have Experience with telecom/network measurement, QoE/QoS systems, or RF/cellular domain knowledge Experience with Android, Java, Kotlin Experience with Kotlin Multiplatform. Experience with embedded systems using C++ Strong understanding of networking fundamentals (IP, TCP/UDP, HTTP/S, WebSocket). Experience with iOS using Objective-C and MRC ## Description Description We are looking for a highly capable Senior iOS Engineer to join our Powered team and take ownership of our iOS SDKs: the CQoE SDK, which telecom carriers and partners embed directly into their own apps to passively measure real-world network quality, and the Speedtest SDK, the core measurement library that powers every Speedtest client.You will be responsible for implementing and maintaining features that perform a wide variety of network measurements on millions of iOS devices.In our classic SDKs, much of this measurement logic lives in a shared C++ library used across Android, iOS, and embedded target, so you'll have an opportunity to work across the Swift, Objective-C and C++ boundary.In our new SDKs, most of this logic lives in a Kotlin Multiplatform project, so you'll have the opportunity to work with the emerging technologies that power our operations.You love to code and appreciate well-designed APIs, as you will need to strike the right balance between SDK and application code.You have experience with the iOS platform, but are interested in both Android and iOS as well as embedded environments.You want to make a better Internet for everyone.If you already use Ookla's tools to check your broadband or mobile data performance, now you have a chance to be a part of the team that produces them.Key ResponsibilitiesDesign, implement, and maintain network measurement features in the CQoE and Speedtest iOS SDKs, consumed by external carrier partners, third-party app developers, and internal client apps.This includes implementation, testing, documentation, deployment, and development supportDesign, implement, and maintain network measurement features in our new Speedtest iOS SDKs, consumed by enterprise customers.This includes implementation, testing, documentation, deployment, and development supportWork on the shared C++ measurement engine used across Android, iOS, and embedded targets by debugging native code and, over time, contributing to and maintaining it directlyBring AI-assisted tooling into coding, QA, and data analysis where it genuinely earns its place, with clear guardrails around safety, privacy, security, and verificationStay hands-on where it counts (technical reviews, architecture discussions, targeted implementation) while taking ownership of delivery end-to-end on the features and fixes you driveRoll out SDK and measurement changes deliberately: gate them behind feature flags, run quality checks, and verify post-release that real-world behavior matches intent before widening exposureJob Requirements5+ years of software development experience, with a solid foundation in data structures, algorithms, and design patternsExperience with iOS using SwiftSubstantial experience building and maintaining SDKs or librariesStrong data literacy: comfortable writing SQL to investigate production and measurement data, using Python (or similar) for analysis, and applying data-quality monitoring practices to catch anomalies before they reach partnersA curious, proactive stance toward AI and modern engineering practicesExcellent debugging, troubleshooting, data analysis skillsStrong time management skills and a self-driven work ethicNice to haveExperience with telecom/network measurement, QoE/QoS systems, or RF/cellular domain knowledgeExperience with Android, Java, KotlinExperience with Kotlin Multiplatform.Experience with embedded systems using C++Strong understanding of networking fundamentals (IP, TCP/UDP, HTTP/S, WebSocket).Experience with iOS using Objective-C and MRCAbout Ookla, an Accenture company, is a global leader in connectivity intelligence that brings together the trusted expertise of Speedtest®, Downdetector®, Ekahau®, and RootMetrics® to deliver unmatched network and connectivity insights.By combining multi-source data with industry-leading expertise, we transform network performance metrics into strategic, actionable insights.Our solutions empower service providers, enterprises, and governments with the critical data and insights needed to optimize networks, enhance digital experiences, and help close the digital divide.At the same time, we amplify the real-world experiences of individuals and businesses that rely on connectivity to work, learn, and communicate.From measuring and analyzing connectivity to driving industry innovation, Ookla helps the world stay connected.About Accenture Accenture helps the world's leading enterprises reinvent by building their digital core and unleashing the power of AI to create value at speed for organizations across industries.Our strategy is to be the reinvention partner of choice for our clients and lead in the safe, widespread adoption of AI, and to be the most client focused, AI-enabled, great place to work in the world.We bring together the talent of our approximately 799,000 people with proprietary assets and platforms, deep process and industry expertise, and leading ecosystem relationships to deliver end-to-end solutions and measurable outcomes at scale.Through our Reinvention Services, we offer broad expertise across Cybersecurity, Digital Core, Finance, Industry and Enterprise, Song, Supply Chain and Engineering, and Talent, with advanced capabilities in AI and Data, Industry and Process, and Technology.We serve approximately 9,000 clients and generated approximately $70 billion in FY25 revenue.Visit us at accenture.com.Compensation Range Ookla provides a range for the base pay.Factors that may be used to determine your actual pay may include your specific job related knowledge, skills, experience, and geographic location.The salary compensation for this role is 50,000 to 63,700 EUR annually.Individual pay within the compensation range for this business unit specific role is determined based on a variety of factors including experience, scope of the role, capabilities to perform the role, education and training, as well as business and company performance.#J-*****-Ljbffr ## Related Videos - [Kotlin Multiplatform - True power of native code reuse](https://www.wearedevelopers.com/videos/4-kotlin-multiplatform-true-power-of-native-code-reuse) - [From DevOps to Scaled DevOps: How We’re Rebuilding Continuous Delivery as a Platform](https://www.wearedevelopers.com/videos/100018-from-devops-to-scaled-devops-how-we-re-rebuilding-continuous-delivery-as-a-platform) - [Minimal infrastructure for Real‑Time Phone Agents: transcripts in, responses out](https://www.wearedevelopers.com/videos/1736-minimal-infrastructure-for-real-time-phone-agents-transcripts-in-responses-out) - [Unlocking the potential of Digital & IT at Vodafone](https://www.wearedevelopers.com/videos/602-unlocking-the-potential-of-digital-it-at-vodafone) - [Build Delightful Mobile Experiences with Kotlin, Realm, and Atlas Device Sync](https://www.wearedevelopers.com/videos/694-build-delightful-mobile-experiences-with-kotlin-realm-and-atlas-device-sync) - [Why 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