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 the agentic AI platform for creating, launching, and scaling paid ads.

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!