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 tools into everyday engineering workflows.

**At Similarweb, collaborating with our colleagues in-office creates a more connected, unified culture. Our best work is a product of our face-to-face collaboration, with the ability to work partially from home.**

Why you’ll love being a Similarwebber:

You’ll actually love the product you work with: Our customers aren’t our only raving fans. When we asked our employees why they chose to come work at Similarweb, 99% of them said “the product.” Imagine how exciting your job is when you get to work with the most powerful digital intelligence platform in the world.

You’ll find a home for your big ideas:  We encourage an open dialogue and empower employees to bring their ideas to the table. You’ll find the resources you need to take initiative and create meaningful change within the organization. 

We offer competitive perks & benefits: We take your well-being seriously, and offer competitive compensation packages to all employees. We also put a strong emphasis on community, with regular team outings and happy hours.

You can grow your career in any direction you choose: Interested in becoming a VP or want to transition into a different department? Whether it’s Career Week, personalized coaching, or our ongoing learning solutions, you’ll find all the tools and opportunities you need to develop your career right here.

Diversity isn’t just a buzzword: People want to work in a place where they can be themselves. We strive to create a workplace that is reflective of the communities we serve, where everyone is empowered to bring their full, authentic selves to work. We are committed to inclusivity across race, gender, ethnicity, culture, sexual orientation, age, religion, spirituality, identity and experience. Our culture of equality and mutual respect also helps us better understand and serve our customers in a world that is becoming more global, more diverse, and more digital every day.

Required:

• 3+ in Windows desktop application development using Windows App SDK, WinUI (or similar), C#, XAML — and ideally additional experience with native Windows code (C++, Win32/WinRT/COM).
• Deep understanding of Windows application architecture, including interop between managed code (.NET) and native code.
• Proven track record of designing, building, and shipping production-quality desktop applications, with an emphasis on reliability, performance, scalability, and maintainability.
• Strong experience with accessibility APIs on Windows (e.g. Microsoft UI Automation or similar), and a dedication to building accessible and inclusive software.
• Excellent software engineering fundamentals: OOP, design patterns, data structures, algorithms, memory management, multi-threading or asynchronous programming (where relevant).
• Experience leading technical design, mentoring other engineers, conducting code reviews, and making architecture-level decisions.
• Strong communication skills; ability to articulate tradeoffs, collaborate with cross-functional teams, and drive consensus.
• A user-centric mindset: focus on building polished, intuitive, and accessible experiences for end users.

Preferred / Bonus:

• Experience with writing automated tests for UI — unit tests, integration tests, UI automation tests; familiarity with relevant testing frameworks.
• Experience with performance optimization for desktop apps (memory usage, startup time, rendering performance, high-DPI support, responsiveness under load).
• Experience with localization/globalization, right-to-left UI support, internationalization, accessibility for multiple regions.
• Familiarity with telemetry, analytics, crash reporting, logging, and error monitoring in desktop applications.
• Previous experience in shaping CI/CD workflows, release pipelines, and deployment strategies for desktop applications.
• Demonstrated ability to take ownership of feature areas or modules and drive them long-term, including maintenance, refactoring, and technical debt management.

What we offer

• A high-impact role: you will define architecture, shape the future of our Windows product, and directly influence what millions of users see and experience.
• A collaborative, flat-structure engineering culture — you are not just a coder, but a builder and a decision-maker.
• Opportunities to lead — mentor others, steer technical direction, and grow into broader technical leadership (e.g. Tech Lead, Architect).
• Flexibility, autonomy, and responsibility: you define how to solve problems, own features end-to-end, and contribute to long-term product vision.
• A purpose-driven mission: building software that’s reliable, accessible, and user-centered — making a real difference for people.                  

Think you’re a good fit for this job? 

Tell us more about yourself and why you're interested in the role when you apply.
And don’t forget to include links to your portfolio and LinkedIn.

Not looking but know someone who would make a great fit? 
Refer them! 

Speechify is committed to a diverse and inclusive workplace. 
Speechify does not discriminate on the basis of race, national origin, gender, gender identity, sexual orientation, protected veteran status, disability, age, or other legally protected status.

Why this role matters
AI makes code generation easier, but proving that code works in production is still hard. This role focuses on closing that gap by building runtime technology that enables safe, real-time validation inside live applications, so engineers and AI agents can verify fixes, changes, and assumptions where they actually matter.

Responsibilities

• Build low-overhead runtime instrumentation and data capture in customer processes across Java, C++ and related environments
• Ensure compatibility across runtime versions, frameworks, and deployment environments such as containers, Kubernetes, Windows, and Linux
• Build backend services to securely define, distribute, and manage agent actions at scale
• Own agent-backend APIs and protocols, including versioning, compatibility, and release strategy across a large installed fleet
• Drive profiling and benchmarking to minimize runtime overhead and enforce 
• performance budgets

Requirements

Must have

• Strong C++ skills with production experience, especially in performance and memory safety
• Production experience with Java and/or .NET, particularly in core libraries, frameworks, or runtime-adjacent components
• Experience building high-performance systems under latency, CPU, and memory constraints
• Strong backend engineering experience designing and operating production services and APIs

Nice to have

• Hands-on experience with profilers and runtime instrumentation technologies, such as:
• Java: JVMTI, bytecode instrumentation, ASM, Byte Buddy, JIT/GC awareness, safe attachment patterns
• .NET: CLR Profiling APIs, ICorProfiler, IL rewriting, managed/unmanaged interop

Vonage Applications: 

Our Applications business unit focuses on delivering a suite of advanced communication tools designed to enhance customer engagement. From cloud contact centers to feature-rich unified communications solutions, our Applications team is dedicated to providing businesses with the tools they need to streamline operations and improve customer experiences.

Why this role matters:

We are an established team driving the innovation of our company’s core audio-call infrastructure. Our current mission is the new development of high-performance services that power real-time audio streaming for external processing, recording services, and external API integrations.

Your key responsibilities:

In this role, you will focus on building new, scalable features from the ground up. While we value full-stack capability, your primary impact will be in Backend and Cloud Engineering using .NET and AWS (ECS/EKS).

You will take ownership of the end-to-end development of new audio-processing logic and the APIs that expose these capabilities to the rest of the organization.

This is a hybrid role, offering the flexibility to work most of the time remotely. However, certain tasks will require in-person collaboration with team members. You should be prepared to attend on-site meetings (Tel-Aviv) occasionally to support key project milestones and ensure successful outcomes.

What you'll bring

• Backend Expertise: 3+ years of professional experience in software development, with a deep focus on C# and the .NET ecosystem.
• Frontend expertise: Working experience with JavaScript
• Containerization & Cloud: Hands-on experience building and scaling services within AWS, specifically using ECS or EKS.
• Systems Engineering Mindset: A proactive attitude toward building new products from scratch, with a focus on high-quality code and scalable design patterns.
• Communication: Strong English skills and the ability to collaborate effectively in a distributed, multicultural environment.

Experience we consider a plus:

• DevOps & Scripting: Experience with CI/CD automation and scripting (e.g., Python, Bash) to streamline development and deployment.
• Performance Analysis: Familiarity with tools and techniques for profiling and optimizing .NET applications in high-load environments.
• Node.js Knowledge: Ability to contribute to or integrate with Node.js-based services.

How you’ll benefit:

• Discretionary Time Off
• Private Medical Healthcare
• Pension scheme
• Ericsson support line
• Hybrid work
• Additional benefits and perks will be shared and discussed with you by the recruiter during the interview process

#LI-JM2