Backend Department Lead (Node.js)

Zeely is an AI platform for creating and scaling paid advertising. They are looking for a Backend Department Lead to lead the backend platform and AI Gateway, with hands-on technical leadership and ownership over high-load systems serving over 2 million businesses.

• Lead the Backend Department and define the technical direction for a team of 15+ backend engineers
• Be responsible for backend architecture, scalability, reliability and system performance
• Develop AI Gateway and AI orchestration pipelines for working with various models and providers
• Optimize routing, fallback strategies, generation quality, latency and cost
• Scale backend services and infrastructure according to product growth
• Maintain high standards of code quality, security, observability and operational reliability
• Develop RAG pipeline, MCP integrations and AI agents
• Remain hands-on in architecture, design review, code review and troubleshooting
• Develop the backend team through mentoring, performance management and hiring
• Collaborate with Frontend, Mobile, QA, AI Engineering, DevOps and Product
• Work with the Principal Engineer on capacity planning, reliability and cost optimization

• 7+ years of backend development with Node.js
• 3+ years in a technical leadership role: Backend Lead, Team Lead or Engineering Lead
• Experience mentoring and performance managing backend engineers
• 3+ years of production experience with NestJS
• Strong system design, microservices and distributed systems skills
• Experience building and scaling high-load systems
• Deep knowledge of PostgreSQL and Redis
• Experience with Prisma, Drizzle or other ORMs
• Practical experience with AWS: EKS, RDS, SQS, S3, CloudWatch, OpenSearch
• Strong knowledge of Docker
• Understanding of reliability, observability, monitoring, incident management and on-call practices
• Ability to combine architectural strategy with hands-on engineering
• English Upper-Intermediate or higher
• AWS Solutions Architect or Developer certification (plus)
• Terraform / Infrastructure as Code (plus)
• Experience with cost, latency and performance optimization (plus)
• Integration of payment systems (plus)
• Backend for mobile and web products (plus)
• GCP and Cloudflare (plus)
• Experience hiring and scaling engineering teams (plus)
• Commercial experience integrating AI APIs: OpenAI, Anthropic, Google and others
• Experience with multi-model orchestration: routing, fallbacks, retries, rate limits, cost/latency optimization
• Understanding of reliability and observability of AI systems
• Experience with Claude Code, GitHub Copilot, Cursor or similar tools
• Understanding of RAG, embeddings, vector search, MCP and AI agents
• Hands-on production experience in these areas is a plus

• Technical ownership over backend platform of a fast-scaling AI product
• Impact on architecture and engineering standards of the entire backend direction
• Work with high-load, distributed systems, AI orchestration and infrastructure at scale
• Direct impact on integration of AI technologies into the product
• Strong engineering team, autonomy and influence on technical decisions
• Remote-first format + offices in Warsaw and Kyiv
• Regular performance reviews and transparent compensation review