Backend Department Lead (Node.js)

Join us as a Backend Department Lead and drive the technical direction and 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 engineering leadership and experience in building and developing high-performing backend teams. In this role, you will have real technical ownership of our AI Gateway, generative pipelines, and mission-critical backend services powering a product already used by more than 2 million people.

About Us:

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

Simply put: we've made the best AI solutions and marketing tools available to small and medium businesses — tools that used to be reserved for big brands with expensive marketing teams.

The next big step: a B2B solution for large marketing teams and enterprise clients — workflows, creative analytics, and full control over campaigns across the whole team. For companies where performance marketing already runs at scale and needs more efficiency and automation.

A few numbers that speak for themselves:

4 years on the market — a stable, profitable company backed by international investors; 6× growth over the past year; 2,000,000+ businesses already use Zeely; #1 in its category in the US market; 200+ specialists on the team; Markets: US + worldwide.

Your Key Responsibilities:

Lead the Backend Department and set the technical direction for a team of 15+ backend engineers; Own backend architecture and drive key technical decisions around scalability, reliability, performance, and system design; Lead the evolution of our AI Gateway — the core platform layer powering text, image, voice, avatar, and video generation across multiple AI models and providers; Design and evolve AI orchestration pipelines, optimizing routing, fallback strategies, generation quality, latency, and cost; Scale backend services and

infrastructure to support growing product traffic and increasingly complex workloads; Drive engineering excellence across code quality, architecture, security, observability, testing, and operational reliability; Lead strategic backend and AI initiatives, including our proprietary RAG pipeline, MCP integrations, and AI agent capabilities; Stay hands-on with architecture, design reviews, code reviews, troubleshooting, and technically complex initiatives; Grow the backend team through mentoring, performance management, technical

development, hiring, and strong engineering practices; Collaborate closely with Frontend, Mobile, QA, AI Engineering, DevOps, and Product teams to translate business goals into scalable technical solutions; Partner with the Principal Engineer on infrastructure strategy, capacity planning, reliability, and cost optimization.

What We Are Looking For:

• 7+ years of commercial backend development experience with Node.js; 3+ years in a technical leadership role such as Backend Lead, Team Lead, or Engineering Lead; Experience leading and developing backend engineers, including mentoring and performance management; 3+ years of hands-on production experience with NestJS; Strong system design skills and proven experience designing and evolving microservice and distributed architectures; Experience building and scaling high-load production systems; Deep expertise in PostgreSQL and Redis, including performance optimization, data modeling, and caching strategies; Experience with ORMs such as Prisma and Drizzle; Hands-on experience with AWS, including EKS, RDS, SQS, S3, CloudWatch, and OpenSearch; Strong practical knowledge of Docker and containerized environments; Strong understanding of reliability, observability, monitoring, incident management, and on-call practices; Ability to balance architectural strategy with hands-on engineering and pragmatic delivery; Upper-Intermediate English or higher.
• Nice To Have: Active AWS Solutions Architect or Developer certification; Experience with Terraform or other Infrastructure as Code tools; Experience optimizing infrastructure and architecture for cost, latency, and performance at scale; Payment systems integration experience; Backend experience across both mobile applications and web products; Experience with GCP and Cloudflare; Experience hiring and scaling engineering teams in fast-growing product companies.
• AI Expertise We Value: Commercial experience integrating AI APIs such as OpenAI, Anthropic, Google, or other model providers; Experience designing multi-model orchestration systems, including routing, fallbacks, retries, rate limits, and cost/latency optimization; Understanding of production challenges around AI workloads, including reliability, observability, and provider dependencies; Experience with AI-assisted engineering and code review tools such as Claude Code, GitHub Copilot, Cursor, or similar; Understanding of RAG, embeddings, vector search, MCP, and AI agents; Hands-on production experience is a strong plus.
• Why it’s exciting to work with us: Take technical ownership of the backend platform behind a rapidly scaling AI product; Shape architecture and engineering standards across a strong backend organization; Work on real production challenges around high-load systems, AI orchestration, distributed architecture, and infrastructure at scale; Build with cutting-edge AI technologies and directly influence how they are integrated into the product; Join a strong engineering team with significant autonomy and direct impact on product and technical decisions; Remote-first approach: work from anywhere, with the option to visit our offices in Warsaw and Kyiv; Regular performance reviews with transparent growth and compensation discussions.
• Recruitment process: Intro Call → Intro with COO & Co-founder → Test Task → Technical Interview → Final Interview → Reference Check → Offer.
• Send us your CV — we'd love to get to know you!