Backend Lead (Node.js)

Join us as a Backend Lead and drive the development of the backend platform behind one of the fastest-growing AI products in the US market. We are looking for a strong technical leader who combines deep expertise in high-load system architecture with hands-on experience in building and scaling engineering teams. In this role, you will have true ownership of our AI Gateway, generative pipelines, and mission-critical backend services powering a product already trusted by more than 1.5 million users. Zeely AI is an AI-powered platform that helps small businesses create viral UGC videos, advertising banners, and high-performing campaigns across Meta and TikTok, making it easier for entrepreneurs to grow and scale their businesses. Your key responsibilities: Lead the Backend Department, driving team growth, planning, estimations, code reviews, mentoring, and engineers' performance management Define the architectural vision and ensure the reliability, scalability, and performance of the backend platform Develop and evolve our AI orchestration layer across multiple models and providers, optimizing generation quality, latency, and cost efficiency Own the evolution of the AI Gateway — the core platform component powering text, image, voice, avatar, and video generation Scale infrastructure and backend services to support product growth and increasing workloads Maintain high engineering standards in code quality, security, observability, and operational excellence Deliver strategic AI initiatives, including our proprietary RAG pipeline, MCP integrations, and AI agent capabilities Collaborate closely with Frontend, Mobile, QA, AI Engineering, and DevOps teams to achieve business goals Partner with the Principal Engineer on infrastructure capacity planning and cost optimization What we’re looking for: 7+ years of commercial experience with Node.js 3+ years of experience in a Lead, Team Lead, or Engineering Manager role with direct people management responsibilities 3+ years of hands-on experience with NestJS Proven experience designing and evolving microservice architectures in production environments Deep expertise in PostgreSQL and Redis Experience working with ORMs such as Prisma and Drizzle Hands-on experience with AWS services, including EKS, RDS, SQS, S3, CloudWatch, and OpenSearch Strong Docker expertise Experience designing reliable, scalable, and observable distributed systems Solid understanding of on-call processes and incident management practices Upper-Intermediate English level or higher Nice to have: Active AWS Architect or Developer certification Experience with Terraform Experience building high-load systems and optimizing cost/latency trade-offs Payment systems integration experience Backend development experience for mobile applications (iOS/Android) and web products Experience with GCP and Cloudflare Experience hiring engineers and building processes in fast-scaling organizations AI expertise we value: Commercial experience integrating AI APIs (OpenAI, Anthropic, Google, and others) Understanding of multi-model orchestration, including routing, fallback strategies, and cost/latency trade-offs Experience with AI-assisted development and code review tools (Claude Code, GitHub Copilot, etc.) Understanding of RAG, embeddings, MCP, and AI agents (hands-on experience is a strong plus) Why it’s exciting to work with us: Work with cutting-edge technologies and contribute to building AI-powered tools Join a strong A-level team that motivates you to grow and achieve more Remote-first approach: work from anywhere, with the option to visit our offices in Warsaw and Kyiv Paid day offs and sick leaves — we care about your work-life balance Regular performance reviews to ensure your growth is transparent and rewarded Financial support — consultations for private entrepreneurs from our dedicated finance team Recruitment process: Intro Call → Test Task → Technical Interview → Final Interview → Reference Check → Offer Send us your CV — we'd love to get to know you!