Senior Software Engineer

You will lead the development of a high-performance JavaScript SDK used as the primary entry point for client-side event collection. This library is embedded directly into customer applications, so it must operate with exceptional reliability, minimal overhead, and strong privacy guarantees.

Your work will influence how engineering teams capture, validate, and transmit user activity data across a wide variety of environments.

What You’ll Do

• You’ll take full ownership of the SDK: architecture, implementation, performance tuning, testing strategy, and developer experience. You’ll collaborate with multiple teams to ensure data is captured consistently and delivered with accuracy, even under unpredictable network or browser conditions.

This is a craft-focused role where small code decisions have large downstream effects.

Why This Work Matters

• This SDK is the first component developers interact with when integrating the platform. Its correctness and efficiency directly affect how downstream systems interpret and process data. When it underperforms, customer analytics, experimentation, personalization, and AI workflows are impacted.

Your contributions will determine:

• How well the SDK behaves across browsers and devices
• How efficiently it loads and executes in production environments
• How reliably events make it from user devices into backend systems
• How developers experience integration, debugging, and ongoing maintenance

Ideal Experience

• Strong background (typically 6+ years) in building production-quality JavaScript libraries or SDKs
• Deep familiarity with browser internals (networking, storage, event models, security restrictions)
• Solid command of JavaScript, TypeScript, and modern build tooling
• Experience with bundlers such as Rollup, Webpack, Vite, ESBuild, or similar
• Proven ability to reduce bundle size and optimize runtime performance
• Strong testing discipline using common frameworks and automation tools
• Understanding of privacy, security, and compliance considerations
• Excellent written communication and documentation habits

How You Work

• You enjoy building tools other developers rely on. You value correctness, clarity, and performance. You’re comfortable dealing with browser quirks, edge cases, and asynchronous behavior. You see SDKs as products - something that must be intuitive, stable, and resilient.

Tools & Technologies You’ll Encounter

• Core: JavaScript, TypeScript, Node.js
• Build Systems: Nx, Rollup, Vite, Babel (or comparable tooling)
• Testing: Jest and cloud-based browser testing platforms
• Privacy & Compliance: Common global data-handling standards
• Infrastructure Concepts: CDN delivery, caching strategies, versioning

Skills You’ll Grow

• Designing SDKs that behave consistently across diverse and legacy environments
• Applying techniques such as tree shaking, lazy loading, and footprint reduction
• Implementing fault-tolerant event delivery with backoff and offline behavior
• Managing consent frameworks and evolving browser privacy controls
• Building developer tooling, diagnostics, and performance instrumentation
• Implementing observability for client-side libraries

Location

Remote-friendly, with openness to candidates in multiple regions.

Hiring Process

1. Intro Conversation - Understanding your background and interest
2. Practical Exercise - A small real-world SDK scenario
3. Technical Deep Dive - Architecture, testing, browser behavior discussion
4. Platform/System Interview - How you think about data flows and integration needs
5. Team Conversations - Collaboration style, ownership mindset, long-term growth

*Apply with an updated CV to learn more.