Software Engineer (Mobile SDK, Android)

Ziff Davis, LLC; Madrid; On-site; EUR 90,000 - 130,000; Full time

Job summary

Ookla is seeking a Senior Android Engineer to own the Android SDKs for CQoE and Speedtest. You will work across Kotlin/Java, JNI/NDK, and a shared C++ engine to implement and maintain measurement features across Android, iOS, and embedded targets.

You will design robust APIs, ensure safety, privacy, and verifiable results while delivering end-to-end features with strong quality controls.

Qualifications

• 5+ years of software development experience.
• Experience with Android using Kotlin and Java.
• Substantial experience building and maintaining SDKs or libraries.
• Strong data literacy: SQL proficiency and Python for data analysis.
• Curious, proactive stance toward AI and modern engineering practices.
• Excellent debugging, troubleshooting, and data analysis skills.
• Strong time management and self-driven work ethic.

Responsibilities

• Design, implement, and maintain network measurement features in the CQoE and Speedtest Android SDKs.
• Work across the JNI/NDK boundary into the shared C++ measurement engine.
• Contribute to testing, documentation, deployment, and development support.
• Roll out SDK changes behind feature flags with quality checks and post-release verification.

Skills

Android Kotlin

Android Java

SDKs/Libraries

SQL

Python

AI mindset

Debugging

Tools

JNI/NDK

C++

Job description

We are looking for a highly capable Senior Android Engineer to join our Powered team and take ownership of our Android 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 Android devices. Much of this measurement logic lives in a shared C++ engine used across Android, iOS, and embedded targets, so you’ll have an opportunity to work across the Kotlin/Java, JNI/NDK, C++ boundary.

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 Android 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 Responsibilities:

Design, implement, and maintain network measurement features in the CQoE and Speedtest Android SDKs, consumed by external carrier partners, third-party app developers, and internal client apps. This includes implementation, testing, documentation, deployment, and development support

Work across the JNI/NDK boundary into the shared C++ measurement engine used across Android, iOS, and embedded targets by debugging native code and, over time, contributing to and maintaining it directly

Bring AI-assisted tooling into coding, QA, and data analysis where it genuinely earns its place, with clear guardrails around safety, privacy, security, and verification

Stay 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 drive

Roll 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 exposure

Job Requirements:

5+ years of software development experience, with a solid foundation in data structures, algorithms, and design patterns

Experience with Android using Kotlin and Java

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 iOS

• Strong understanding of networking fundamentals (IP, TCP/UDP, HTTP/S, WebSocket).

Experience with embedded systems using C++

About

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 .