Backend Department Lead (Node.js)

The posting

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!