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Sportradar, a NASDAQ-listed sports technology company, is seeking a Senior Software Engineer to build and extend SDKs and embeddable widgets that deliver live sports data, odds, and content to hundreds of operators and millions of end users worldwide.
You will work on a full-stack SDK platform, focusing on four core areas:
**SDK Development:** Extend the SDK within its existing architecture by building new modules, integrations, and TypeScript definitions while maintaining quality and test coverage.
**Widget Development:** Create embeddable widgets that render correctly inside partner pages. You will translate design mocks into responsive, themeable, and accessible UI components without requiring a dedicated front-end specialist for final implementation.
**API Integration:** Integrate internal services and partner APIs into the SDK and widget layer across REST, WebSocket, and Server-Sent Events (SSE). You will implement the retries, reconnection logic, caching, and graceful degradation required for live sports data reliability.
**AI-Augmented Engineering:** Ship daily with AI coding agents and embed that practice into repositories. You will develop context files, reusable skills and commands, and MCP server integrations. You will maintain fast feedback loops with typecheck, lint, and test commands that enable agent autonomy.
**Developer Experience:** Maintain documentation, runnable examples, and error messages that integrating partners depend on. Your users are other developers, so clear communication is essential.
This is a hands-on delivery role. You will ship within established foundations alongside experienced Staff and Senior Engineers who provide mentorship and guidance. The company is building its engineering practice around modern tools and AI agents, and your workflow experience with these tools carries as much weight as traditional seniority.
Sportradar operates an office-first model with five days per week on-site in Ljubljana, though certain exemptions may apply depending on location.
**Requirements:**
- 3+ years of production JavaScript/TypeScript development
- Strong proficiency in JavaScript and TypeScript with solid browser fundamentals (DOM, event loop, modern bundling tools like Vite, Rollup, esbuild, and module formats)
- Daily experience with AI coding agents beyond simple prompting; ability to explain how you structure projects for agent effectiveness and where you do not trust them
- Proven ability to consume HTTP and real-time APIs, including browser-side authentication, CORS handling, and graceful failure modes
- Sufficient CSS and layout skill to build moderately complex widgets from mocks independently
- Clear writing for a developer audience and instinct to communicate early to avoid building the wrong thing
**Preferred Skills:**
- Background in sports betting, iGaming, trading, or other real-time, high-frequency data environments
- Testing depth across unit, integration, and browser automation (e.g., Vitest, Playwright) including visual regression testing
- Experience with performance optimizations in third-party contexts (bundle size, lazy loading, impact on host pages you do not own)
- CI/CD experience and release automation
- Familiarity with AWS services and infrastructure
