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, Cloud. Watch, and Open. Search;
• 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!