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!