Backend Department Lead (Node.js)

Join us as a Backend Department Lead and spearhead the technical direction and development of the backend platform for one of the fastest-growing AI products on the US market.

We are looking for a strong technical leader who combines deep expertise in high-load system architecture with hands-on technical leadership and experience in building and developing high-performing backend teams. In this role, you will have true technical ownership of our AI Gateway, generative pipelines, and critical backend services for a product already used by over 2 million people.

About us:
Zeely is an AI-agent platform for creating, launching, and scaling paid advertising.

Simply put: we have made top-tier AI solutions and marketing tools accessible to small and medium-sized businesses—tools that were previously affordable only for large brands with expensive marketing teams.

Our next major step is a B2B solution for large marketing teams and enterprise clients, featuring workflows, creative analytics, and full campaign control for the entire team. It is designed for companies where performance marketing is already operating at scale and requires greater efficiency and automation.

Numbers that speak for themselves:

4 years on the market—a stable, profitable company backed by international investors;
6x growth over the past year;
Used by over 2,000,000 businesses;
#1 in its category on the US market; A team of 200+ specialists;
Markets: USA + global.


Your key responsibilities:

Lead the Backend Department and define the technical direction for a team of 15+ backend engineers;
Oversee backend architecture, scalability, reliability, and system performance;
Develop the AI ​​Gateway and AI orchestration pipelines to work with various models and providers;
Optimize routing, fallback strategies, generation quality, latency, and costs;
Scale backend services and infrastructure in line with product growth;
Uphold high standards for code quality, security, observability, and operational reliability;
Develop RAG pipelines, MCP integrations, and AI agents;
Remain hands-on with architecture, design reviews, code reviews, and troubleshooting;
Develop the backend team through mentoring, performance management, and hiring;
Collaborate with Frontend, Mobile, QA, AI Engineering, DevOps, and Product teams;
Work with the Principal Engineer on capacity planning, reliability, and cost optimization.


What we are looking for:

7+ years of backend development experience with Node.js;
3+ years in a technical leadership role (Backend Lead, Team Lead, or Engineering Lead);
Experience mentoring and managing the performance of backend engineers;
3+ years of production experience with NestJS;
Strong skills in system design, microservices, and distributed systems;
Experience building and scaling high-load systems;
Deep knowledge of PostgreSQL and Redis;
Experience with Prisma, Drizzle, or other ORMs;
Hands-on experience with AWS: EKS, RDS, SQS, S3, CloudWatch, OpenSearch; Strong knowledge of Docker;
Understanding of reliability, observability, monitoring, incident management, and on-call practices;
Ability to combine architectural strategy with hands-on engineering;
English proficiency: Upper-Intermediate or higher.

A plus:

AWS Solutions Architect or Developer certification;
Terraform / Infrastructure as Code;
Experience with cost, latency, and performance optimization;
Payment system integration;
Backend development for mobile and web products;
GCP and Cloudflare;
Experience hiring and scaling engineering teams.

AI expertise we value:

Commercial experience integrating AI APIs (OpenAI, Anthropic, Google, etc.);
Experience with multi-model orchestration: routing, fallbacks, retries, rate limits, cost/latency optimization;
Understanding of AI system reliability and observability;
Experience with Claude Code, GitHub Copilot, Cursor, or similar tools;
Understanding of RAG, embeddings, vector search, MCP, and AI agents;
Hands-on production experience in these areas is an advantage.

Why work with us:

Technical ownership of the backend platform for a rapidly scaling AI product;
Influence on the architecture and engineering standards of the entire backend function;
Work with high-load, distributed systems, AI orchestration, and infrastructure at scale;
Direct impact on the integration of AI technologies into the product;
Strong engineering team, autonomy, and influence on technical decisions;
Remote-first format + offices in Warsaw and Kyiv;
Regular performance reviews and transparent compensation reviews. 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 better!