Senior Full-Stack Engineer (NestJS and React)

This a Full Remote job, the offer is available from: Europe, EMEA, Ukraine N-iX is looking for a Senior Full-Stack Engineer to join a team modernizing a large ERP/PSA platform for a US-based software company. This role combines hands-on development with technical decision-making, with approximately 55% backend and 45% frontend work. You will build new features, explore complex business logic, and help shape the platform’s evolution using TypeScript, NestJS, React, and Azure. Responsibilities: • Design and implement end-to-end features using NestJS and React. • Analyze the existing codebase, understand business workflows, and contribute to the gradual modernization of the platform. • Design and optimize relational database schemas and queries. • Participate in system design, architecture discussions, and technical decision-making. • Work directly with technical and business stakeholders to clarify requirements and translate business needs into solutions. • Ensure solutions meet security, performance, scalability, and maintainability requirements. • Contribute to code reviews, automated testing, and CI/CD improvements. • Identify technical risks, manage dependencies, and proactively communicate delivery concerns. • Contribute to backlog refinement, planning, and Agile ceremonies. Requirements: • 5+ years of commercial software engineering experience, including backend and frontend development with TypeScript. • Hands-on experience with NestJS and React. • Practical experience building and integrating REST APIs and GraphQL. • Experience developing complex backend systems with substantial business logic. • Solid understanding of distributed systems and microservices-based architectures. • Strong expertise in relational databases such as MySQL or PostgreSQL, including schema design, query optimization, and performance analysis. • Hands-on experience with Apache Kafka. • Hands-on experience with Microsoft Azure. • Experience analyzing large legacy codebases and working with limited documentation. • Experience contributing to system design and technical decisions. • Strong analytical, problem-solving, and stakeholder communication skills. • Experience working in Agile, Scrum, or Kanban teams. • Upper-Intermediate or higher English and proficiency in Ukrainian for daily team communication. Nice to have: • Experience with ERP platforms, financial systems, enterprise SaaS, multi-tenant applications, or large B2B portals. • Experience with stored procedures, database functions, and complex SQL. • Knowledge of PHP and Microsoft SQL Server, particularly stored procedures. • Experience reverse engineering existing systems and incrementally modernizing legacy applications. • Experience with AI-assisted development tools such as GitHub Copilot, Claude, or Cursor. We offer: • Flexible working format - remote, office-based or flexible • A competitive salary and good compensation package • Personalized career growth • Professional development tools (mentorship program, tech talks and trainings, centers of excellence, and more) • Active tech communities with regular knowledge sharing • Education reimbursement • Memorable anniversary presents • Corporate events and team buildings • Other location-specific benefits not applicable for freelancers This offer from "N-iX" has been enriched by Jobgether.com and got a 0% flex score.