Senior Backend Engineer, NodeJS

This is a fully remote position, open to applicants in Serbia.

📋 Description

• Design and construct backend architecture for AI-driven automation systems.

• Collaborate with AI engineers and product teams to integrate and enhance LLM-based product features.

• Implement and advance agent-based systems, including ReAct and supervisor-agent models.

• Optimize RAG pipelines and context enrichment utilizing both structured and unstructured data.

• Create robust APIs for internal services and external integrations.

• Ensure observability, monitoring, and alerting through tools such as Grafana and OpenSearch.

• Engage in code reviews and participate in architecture discussions.

• Maintain comprehensive technical documentation for newly designed systems and APIs.

• Collaborate with AI engineers, product teams, and cross-functional stakeholders.

• Develop production-grade systems that automate clinical and operational workflows.

⛳️ Requirements

• Over 8 years of commercial backend development experience with Node.js in product-focused companies, ideally SaaS.

• Profound understanding of complex backend systems from end to end.

• Experience in designing backend architectures and crafting technical solutions.

• Familiarity with system decomposition, scalability trade-offs, long-term maintainability, and technology selection.

• Proven track record of building scalable, high-performance backend systems and resilient APIs.

• Understanding of data flows, potential failure modes, and performance bottlenecks.

• Practical experience integrating LLMs into production environments.

• Experience in designing and implementing multi-agent AI workflows in production.

• Hands-on experience with modern AI frameworks.

• Experience in designing and optimizing RAG pipelines, including embeddings, vector databases, retrieval strategies, ranking, chunking, and quality-versus-latency trade-offs.

• Strong skills in prompt engineering, including structured outputs, schema validation, evaluation-based iteration, and reliability techniques.

• Knowledge of LLM infrastructure in production, including tracing, observability, evaluation frameworks, quality metrics, safety mechanisms, guardrails, and performance/cost optimization.

• Hands-on experience with PostgreSQL and AWS, encompassing CDK, Lambda, API Gateway, and ElastiCache.

• Solid understanding of observability and debugging practices, including tools like Grafana and OpenSearch or similar.

• Experience with testing, CI/CD, reliability, and technical ownership.

• Product-oriented mindset.

• Proactive enthusiasm for AI.

• Fluent in Russian.

• English proficiency at B2 level or higher.

• Experience in medical/healthcare AI or regulated environments is a plus.

• Familiarity with MCP in Node.js is an advantage.

🏝️ Benefits

• Competitive compensation package.

• Fully remote long-term collaboration under a B2B model.

• Health insurance provided after the probation period.

• Compensation for sports and wellness activities.

• Tailored English lessons through Preply.

• Clear pathways for career growth.

• 19 paid vacation days per year.

• 4 additional wellness days annually.

• Paid sick leave for the first 5 working days.

• Thoughtful gifts for significant life events.

• Offline corporate events.