Senior Fullstack Engineer

Description:

Join us at Nayax, a global fintech leader (NASDAQ; TASE: NYAX) revolutionizing the world of cashless payments, consumer engagement, and business management solutions. With more than 1,200 employees across 12 offices worldwide. At Nayax, you’ll be part of a diverse and innovative community where your work makes a real impact and helps shape the future of payments.

We are currently looking for a Senior Full‑Stack Developer who will own end-to-end delivery of scalable, high‑impact features across our web applications and services. You’ll work across the stack with Node.js, NestJS, React, and TypeScript, backed by MongoDB, and you’ll help evolve our CI/CD pipelines and cloud-native practices. This role is ideal for someone who loves building robust systems, cares about developer experience, and enjoys mentoring others.

The Senior Fullstack Engineer will report directly to the Director of R&D.

Your key responsibilities will include:

• Design, build, and maintain production services and web apps using Node.js (NestJS) on the backend and React (TypeScript) on the frontend.
• Architect and implement REST/GraphQL APIs, optimize data models and queries in MongoDB, and ensure performance, reliability, and security.
• Own the full SDLC: scoping, design reviews, implementation, testing (unit/integration/e2e), deployment, monitoring, and incident response.
• Drive and improve CI/CD pipelines (e.g., GitHub Actions/GitLab CI/Azure DevOps), including build, test, security scans, and zero‑downtime deploys.
• Collaborate closely with Product, Design, and Data to deliver features that move key business metrics.
• Champion engineering best practices: code quality, code reviews, documentation, observability, and performance tuning.
• Mentor teammates and contribute to architectural decisions, standards, and tooling.
• (Bonus) Contribute to event-driven and search/analytics initiatives leveraging Kafka, OpenSearch, Argo CD, and Python for data flows/automation.

• Minimum 6+ years of hands-on software development experience - Must
• predominately in JavaScript/TypeScript - Must.
• Strong production experience with Node.js and NestJS - Must (or equivalent Node frameworks) , building scalable APIs/services.
• Strong production experience with React - Must , including state management and modern React patterns.
• Solid experience with MongoDB - Must (schema design, indexing, aggregation, performance profiling).
• Proficiency with Git workflows, code reviews, and trunk- or git‑flow‑based development.
• Practical experience building and maintaining CI/CD pipelines (containerized builds, test automation, artifact/versioning, environment promotion).
• Deep understanding of testing methodologies (unit, integration, E2E), security basics (OWASP), and production monitoring.
• Experience with containers (Docker) and cloud deployment (Kubernetes or container orchestrators is a plus).
• Strong communication, collaboration, and ownership mindset.

Nice‑to‑Have (Bonus) Experience:

• Kafka (producers/consumers, schema, exactly-once/at-least-once semantics, dead-letter queues).
• OpenSearch / Elasticsearch (indexing strategies, relevance tuning, aggregations, ILM).
• Argo CD and GitOps workflows for Kubernetes deployments.
• Python for scripting, data tooling, or ML/analytics integration.
• API gateway patterns, rate limiting, and auth (OAuth2/OIDC/JWT).
• Observability stack: Prometheus/Grafana, OpenTelemetry, ELK/EFK, or vendor solutions (Datadog, New Relic).
• Performance optimization in both frontend (bundle splitting, profiling, RUM) and backend (caching, async/streaming, profiling).

Tech Stack You’ll Touch:

• Frontend: React, TypeScript, Vite/Webpack, Testing Library/Jest/Cypress
• Backend: Node.js, NestJS, REST/GraphQL, Jest, Supertest
• Data: MongoDB, Redis (caching/queues)
• Infra/DevEx: Docker, Kubernetes, CI/CD (e.g., GitHub Actions/GitLab/Azure DevOps), feature flags
• Observability/Sec: OpenTelemetry, OpenSearch/ELK, SAST/DAST, secrets management
• Bonus: Kafka, Argo CD, Python