FullStack Engineer (Node.js) (m/f/n)

We are looking for a FullStack Engineer (Backend Heavy & Data Centered) to join an international engineering team building systems that support financial and operational workflows.This is a role for someone who is strongly backend-oriented (80%) and highly data-aware, not just writing APIs, but understanding how data moves across the organisation and how it should be exposed safely and reliably.You will work on a platform that integrates multiple internal and third-party systems, where the core challenge lies in reliably fetching, transforming, and exposing data through scalable services and API gateways. The role focuses on building robust integration layers, ensuring data consistency across systems, and designing solutions that support secure and efficient data flows across the organisation. Part of the landscape also includes integration and process automation tools, so experience with automation platforms is considered an advantage.You’ll work closely with Data Engineers, as well as a full-stack engineering team in Warsaw, and international stakeholders across multiple countries.What we offerRate: up to 20 000 PLN/month netto+ VAT Hybrid work model (2 days a week from Warsaw).B2B ContractResponsibilitiesDesign, develop, document, and maintain scalable backend systems and REST APIsBuild and manage integrations across multiple internal and external systemsModel and implement secure, high-performance relational databasesContribute to an internal master data management (MDM-like) systemMaintain and optimize backend infrastructure in cloud environmentsSupport automation flows and integration processes (Workato)Collaborate with FullStack, Application, and Data EngineersSupport React / Next.js applications when requiredOwn features from concept through deploymentProvide maintenance and troubleshooting across backend services and integrationsRequirements5+ years of experience with TypeScript and Node.js (& Javascript ecosystem)Strong experience with relational databases (PostgreSQL)2+ years of experience with React or React frameworks (Next.js)Experience with cloud infrastructure (GCP preferred or similar)Familiarity with KubernetesExperience with integration testingStrong understanding of backend architecture, caching, and design patternsSolid knowledge of security best practicesProficiency with GitStrong English communication skillsAbility to work independently and manage multiple initiativesExperience working in international distributed teamsPreferably a university degree in Computer Science (or similar technical background)Nice to HaveExperience with Workato or similar automation platformsExperience with NestJS or BunInfrastructure as Code (Terraform)Microservices architecture experienceExperience with caching solutions (Redis, Memcache)Familiarity with SSO, Cloudflare, or OktaExperience with PythonExperience documenting APIs (OpenAPI or similar)