Senior Backend & Data Engineer (JavaScript/TypeScript)

Quick Facts

• Hybrid in Warsaw (2 days remote / 3 days office)

Description

Senior Backend & Data Engineer focused on complex database solutions, data architecture, and Master Data Management (MDM). You will design, develop, and optimize backend services and data-driven applications using JavaScript and TypeScript, with a primary focus on relational databases (especially PostgreSQL). You will take end-to-end technical ownership of a dedicated data domain, including integrations and improvements to reliability and maintainability.

Responsibilities

• Design, develop, and maintain scalable backend services and data-driven applications using JavaScript and TypeScript
• Design and implement complex relational database structures, primarily with PostgreSQL
• Own a dedicated data domain end to end, ensuring reliability, consistency, and maintainability
• Develop and optimize data models, database schemas, queries, and backend data processing
• Design and maintain backend solutions for data handling, transformation, and integration across systems
• Apply Master Data Management (MDM) principles for data consistency, integrity, quality, and reliability
• Build and maintain integrations between backend services, databases, and enterprise systems
• Identify opportunities to improve data architecture, performance, scalability, and maintainability
• Independently analyze technical challenges, propose solutions, and implement them
• Collaborate with international engineering teams and business and technical stakeholders

Requirements

• 8+ years of professional software engineering experience with backend development and data-intensive applications
• Strong hands-on experience with JavaScript and TypeScript in backend environments
• Advanced knowledge of relational databases, particularly PostgreSQL or comparable technologies
• Proven experience designing and maintaining complex database schemas and data models
• Solid understanding of database architecture, performance optimization, data integrity, and data consistency
• Experience building backend systems involving complex data processing, transformation, or integration
• Understanding of Master Data Management (MDM) principles, including data quality, consistency, and cross-system management
• Experience designing and developing APIs and backend integrations
• Ability to independently own technical solutions and make architectural and implementation decisions
• Strong analytical thinking, problem-solving, and attention to data quality
• Excellent communication skills and fluency in English

Nice to Have

• Experience in international/distributed engineering teams
• Ownership of a business-critical data domain
• Hands-on MDM implementation or working with enterprise master data
• Experience with Node.js frameworks such as NestJS or Express
• Data engineering experience (data pipelines, ETL/ELT, data transformation workflows)
• Integrations across multiple enterprise systems
• Knowledge of data governance, data lineage, and data quality frameworks
• Cloud/data platforms experience (AWS, Azure, or GCP)
• Experience in complex enterprise technology environments