Senior Fullstack Engineer

Senior Engineer will be responsible for the development of the OnetAds platform (onetads.pl) and e-commerce services such as Skapiec.pl and Lamoda.pl. The role involves active participation in building new functionalities, optimizing existing solutions, and supporting the Content Commerce area. The position requires solid fullstack experience with a focus on a modern stack based on Node.js/(NestJS), React/Next.js using Elasticsearch and PostgreSQL as main data layers.

• Minimum 4-5 years of experience in web software development
• Very good knowledge of Node.js (NestJS)
• Good knowledge of React or Next.js
• Practical knowledge of Opensearch — indexing, searching, query optimization
• Experience with PostgreSQL — data modeling, query optimization, migrations
• Ability to design and implement API interfaces: GraphQL and REST
• Experience with microservices and containerization
• Basic knowledge of AWS Cloud services (EC2, S3, RDS, CloudFront, etc.)
• Experience with Amazon EKS (Kubernetes on AWS)
• Experience working with AI agents / agentic coding tools: Claude Code, GitHub Copilot, Codex
• Ability to work independently and make technical decisions
• Knowledge of English

Nice to have:

• Knowledge of AWS SQS/SNS queues — messaging, event-driven architecture
• Experience in e-commerce, AdTech, or Content Commerce industry
• Experience with CI/CD (GitHub Actions)
• Knowledge of monitoring and observability tools (Grafana, CloudWatch, Prometheus)
• Knowledge of Tailwind CSS

• Development and maintenance of the OnetAds platform and Skapiec.pl and Lamoda.pl services
• Designing and implementing new fullstack functionalities (80% backend, 20% frontend)
• Building and developing API interfaces (GraphQL and REST)
• Optimizing search performance and indexing in Opensearch
• Collaborating with product and business teams in the Content Commerce area
• Participating in code reviews, architectural planning, and technical decisions
• Ensuring code quality, testing, and technical documentation