Software Engineer - Innovation team

At Similarweb, we are revolutionizing the way businesses interact with the digital world by revealing to them everything that happens online. Our unique data and solutions empower thousands of customers globally, including industry giants like Google, eBay, and Adidas, to make game-changing decisions that drive their digital strategies. In 2021, we went public on the New York Stock Exchange, and we continue to reach new heights! Come work alongside Similarwebbers across the globe who are bright, curious, practical and good people We’re looking for a Software Engineer to join our Data Collection Technologies team to contribute to the design, build, and maintain Similarweb’s Desktop data-collection extensions and client-side components. In this role, you will work as part of a team responsible for developing high-performance browser extensions ,desktop-level integrations and Mobile SDKs that power our data collection platform. Why is this role so important at Similarweb? As the most trusted platform for measuring online behavior, millions of people rely on Similarweb’s insights daily as the ground truth for their knowledge of the digital world. Producing these insights requires large scale raw data to be ingested reliably in high scale to provide stable signals for analysis. As a Desktop Client-Side Developer, you will own and implement core components of Similarweb’s desktop & mobile data-collection technologies. You’ll work hands-on to design, develop, and optimize our desktop clients and browser extensions, ensuring accurate, reliable, and high-quality data collection. Your work will directly influence the performance, stability, and integrity of the data that powers Similarweb’s products and insights. So, what will you be doing all day? Design and write (a lot of) high-quality, functional code of cutting edge SDK's, distributed on millions of devices (JavaScript , Kotlin, Swift). Tackle challenges and find creative and innovative ways to solve them. Determine feasibility & take part in decision-making by performing risk management and evaluating trade-offs. Contribute to your team development velocity and quality confidence. Improve your skills, learn from and mentor top-notch engineers and enrich other team members. Perform code reviews, evaluate implementations, and provide feedback. This is the perfect job for someone who: 5+ years of hands-on experience building high-performance software products. B.Sc. or M.Sc. in Computer Science, Software Engineering or a related technical field (or equivalent experience). Strong software development skills; deep expertise in at least two of the following domains: Node.js, frontend/web internals (e.g. React), JavaScript/TypeScript, or browser/Chromium internals. Ability to work at a low level: understand and work with web-development internals, browser APIs, and extension platform mechanics. Experience with RESTful APIs and designing secure data handling within browser extensions. Strong debugging and investigative skills: able to research, triage and resolve complex issues that arise from browser/extension integration. Ability to own features end-to-end: from design and architecture through development, testing, deployment and maintenance. Prior experience building or maintaining browser-extensions or plugins (e.g. for Chrome, Edge, Firefox, or other browsers). Familiarity with browser-extension lifecycle and security challenges, including manifest-based extension development (e.g. Manifest V2 / V3), sandboxing, permissions model, secure data flow, etc. Nice-to-have (bonus) skills / experience Prior experience building desktop applications for Windows or macOS (Electron, .NET, Swift, or similar). Familiarity with automated testing frameworks and relevant tooling (unit tests, integration tests, extension testing frameworks, end-to-end testing). Hands-on experience with AI-powered development environments (e.g., Cursor, Claude Code) and a demonstrated track record of integrating AI too