Senior Backend Engineer (Node.js)

O projekcie: We are the company behind CKEditor — an open-source rich text editor used by millions of people around the world. We are part of Tiugo Technologies, a family of API-first developer platforms (CKEditor, TinyMCE, ButterCMS, Uploadcare) focused on content creation and digital collaboration. Your role: As an Engineer on our AI team, you will drive the evolution of AI capabilities powering CKEditor 5 — working at the intersection of AI and content creation, where LLMs meet their most natural application: text processing. You'll design prompt strategies, integrate models from providers like OpenAI, Anthropic, and Google Gemini, and build intelligent features such as contextual text predictions, automated content generation, and advanced text processing.  Our core stack is TypeScript and Node.js. We're looking for an engineer with genuine passion for AI and a solid backend foundation - someone who can build production-grade services, not just prototypes, and who balances cutting-edge innovation with robust implementation. Wymagania: - Over 5 years of software development experience. - Strong proficiency in TypeScript and Node.js. - Experience building and maintaining backend services - REST APIs, relational databases (PostgreSQL), message queues, Docker. - Fluency in Polish (minimum C1) and good command of English (minimum B2) - Excellent problem-solving skills and the ability to think critically and creatively. - Outstanding communication skills, both verbal and written. Nice to have: - Experience integrating third-party APIs (LLM providers, external services). - Understanding of AI/LLM concepts - prompt engineering, function/tool calling, streaming. - Experience with cloud infrastructure (AWS - SQS/SNS, S3, ECR). - Familiarity with observability tools (OpenTelemetry, tracing) - Curiosity about AI and willingness to learn how LLMs work. - Experience with event-driven architectures and real-time data processing (streaming, WebSockets, or similar). Codzienne zadania: - Design, build, and maintain backend services for CKEditor 5 - including REST APIs, real-time streaming, event-driven processing, and data persistence. - Build and maintain a multi-service architecture with message queues, caching, and async communication patterns. - Engage in code reviews, pair programming, and cross-functional collaboration to ensure the highest quality results. - Write clean, maintainable, and well-structured code, balancing readability with appropriate documentation. - Share best practices on programming standards, tools, and processes to foster continuous improvement.