Senior Full-Stack Engineer (NestJS and React)

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