Senior Full-Stack Data Engineer (Node.js and React.js)

Our Customer:
A global product company in the cybersecurity domain, focused on helping organizations identify and reduce risks across modern IT environments.
Your Tasks:
Develop and maintain production features across the full stack, from the React UI through the API to the database.
Design, maintain and troubleshoot Node.js and TypeScript backend services and production APIs.
Maintain and enhance the React front end, including modern React patterns, data flow and UI performance.
Own the data access layer in Node.js/TypeScript, keeping control over generated SQL and performance-critical behavior.
Design and evolve database schemas, relationships, constraints and data integrity rules.
Diagnose and optimize slow queries and production bottlenecks using execution plans and index analysis.
Plan and execute production database migrations with backward compatibility and minimal downtime.
Trace and resolve production incidents across the UI, API, data access layer and database.
Interface directly with the international client and engineering team in live technical discussions.
Deliver high-quality, resilient software updates with limited supervision.
Required Experience and Skills:
8+ years of professional software engineering experience, including recent hands-on full-stack work in production systems.
Strong hands-on experience with Node.js and Node.js frameworks such as NestJS or Hapi.js.
Expert-level knowledge of TypeScript in both backend services and data access layers.
Strong production experience with React, including modern React patterns and state and data flow.
Hands-on experience with state management libraries (MobX or Redux).
Strong practical SQL skills, preferably with PostgreSQL.
Hands-on experience with complex JOINs, aggregations and filtering on large datasets.
Proven ability to diagnose slow queries using EXPLAIN and ANALYZE, execution plans and index effectiveness validation.
Experience designing and maintaining data access layers with query builders or ORM tools.
Practical experience with schema design, normalization and denormalization decisions, constraints and data integrity.
Hands-on experience with multi-step transactional operations, rollback behavior, race conditions and transaction isolation trade-offs.
Experience with production database migrations, schema versioning, backward-compatible changes and zero-downtime deployment approaches.
Strong REST API experience, including over-fetching, N+1 problems, latency and efficient mapping of database data into API responses.
Demonstrated ability to trace production issues across the UI, API, data access layer and database.
Experience in production environments with large record volumes and high load.
Experience working in an Agile environment, maintaining code quality through peer reviews and testing.
Proven ability to work autonomously, clarify requirements and drive tasks to completion without continuous follow-up.
Proven ability to take ownership of outcomes across the full stack rather than a single component.
Proven ability to raise risks, blockers and missing information early and provide clear status updates.
Ability to enter an existing codebase and domain, absorb context quickly and adapt to established engineering practices.
Ability to receive direct feedback, discuss disagreements professionally and adjust quickly.
English – Upper-Intermediate
Would Be a Plus:
Hands-on experience with GraphQL schemas, resolvers and integration
Experience with Next.js and server-side rendering
Experience with stored procedures and database-side performance-critical logic
Experience with Redis and caching strategies that reduce unnecessary database load
Experience with AWS and cloud-based production environments
Exposure to Docker, Kubernetes and CI/CD pipelines
Background in cybersecurity or identity management
Experience with large-scale identity data (Active Directory or Entra ID)
Experience with data-intensive, analytics or enterprise high-load products