Software Engineer – SDK & AI

VWO is building the future of experimentation with its innovative SDKs that power millions of user interactions. The Software Engineer – SDK & AI will design and maintain developer-facing SDKs and build AI-driven features to enhance experimentation and decision-making.

Responsibilities:

• Design, build, and maintain VWO's customer-facing SDKs across multiple languages, including Node.js, Java, Python, PHP, Go, and Ruby
• Own the complete SDK lifecycle—from API design and implementation to versioning, backward compatibility, release management, and developer documentation
• Continuously improve SDK performance, reliability, usability, and developer experience
• Partner closely with product and backend teams to deliver robust integrations and platform capabilities
• Build AI-driven features that help customers experiment faster, automate workflows, and make better product decisions
• Integrate and evaluate LLM-based capabilities using commercial and open-source models
• Contribute to AI workflows, prompt engineering, evaluation frameworks, and product intelligence initiatives
• Build and maintain automated testing frameworks for SDKs and product features
• Develop unit, integration, end-to-end, and performance test suites
• Improve release quality through automation, CI/CD practices, and observability
• Investigate customer-reported issues, troubleshoot production problems, and leverage modern AI-assisted development tools to accelerate resolution

Requirements:

• 2+ years of professional software engineering experience with a strong backend or platform engineering focus
• Experience building or maintaining SDKs, developer tools, libraries, APIs, or platform infrastructure
• Strong programming skills in at least one of Node.js, Java, PHP, Python, or Go
• Solid understanding of REST APIs, distributed systems fundamentals, and software design principles
• Hands-on experience integrating LLMs or GenAI capabilities into applications using platforms such as OpenAI, Anthropic, or open-source models
• Experience writing automated tests, including unit, integration, and end-to-end tests
• Practical experience with databases and infrastructure technologies such as MySQL, Redis, Docker, and BigQuery
• Strong engineering fundamentals around code quality, debugging, performance, testing, and CI/CD
• Experience building and maintaining public SDKs with a focus on backward compatibility, version management, and developer experience
• Experience with AI developer tooling such as LangSmith, LangFuse, evaluation frameworks, or agent workflows
• Familiarity with feature flagging, A/B testing, experimentation platforms, or progressive rollouts
• Experience building features behind feature flags and measuring rollout success through experimentation metrics
• Experience developing cross-platform SDKs or contributing to open-source projects
• Exposure to cloud-native environments, containerized systems, and observability platforms
• Experience with performance optimization, monitoring, and production reliability engineering
• Comfort working in fast-moving product environments with evolving requirements and high ownership