Backend Lead

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!