Senior Fullstack (Node.js + React.js) at OnHires

Capon Bridge, West Virginia, United States -

Full Time

Start Date

Immediate

Expiry Date

16 Feb, 26

Salary

0.0

Posted On

18 Nov, 25

Experience

5 year(s) or above

Remote Job

Yes

Telecommute

Yes

Sponsor Visa

Skills

Node.js, NestJS, React.js, Next.js, TypeScript, PostgreSQL, AWS, REST APIs, CI/CD, Git, Docker, Kubernetes, Terraform, Observability, Test Automation

Industry

Staffing and Recruiting

Description

Location: Warsaw, Poland (Hybrid — 2–3 days/week in the office) Employment: Full-time, B2B contract Language: English About the Company The hiring company is an independent product-based SaaS organization with a portfolio of 10+ in-house B2C digital products. The company builds and scales its own products - no outsourcing, no external clients, and no investor pressure. The engineering function operates in a hybrid model in Warsaw, where collaboration 2–3 days per week in the office is required. About the Role The company is seeking a Senior SDE Fullstack who will take full hands-on ownership of backend and frontend feature development, contribute to architecture decisions, ensure performance, and maintain code quality across a modern SaaS environment. This is a senior individual contributor role, fully hands-on - without people-management responsibilities. What You’ll Do Hands-On Engineering (Backend & Frontend) Build and deliver complex features end-to-end using Node.js, NestJS, React.js, Next.js, TypeScript. Design and implement scalable backend services and secure REST APIs. Develop performant frontend components, SSR flows, routing, and state management. Write clean, maintainable, well-tested code. Participate in architectural discussions within the product team. Performance, Reliability & Observability Implement and refine logging, monitoring, and alerting (Sentry, Datadog, Groundcover). Troubleshoot and optimize backend and frontend performance. Participate in incident resolution and root-cause analysis. Improve system reliability, traceability, and error visibility. CI/CD, Git & DevOps Collaboration Maintain and enhance CI/CD pipelines (including GitHub Actions). Work with DevOps to ensure consistent and stable environments across dev/staging/production. Manage and contribute to Git branching strategies (Git Flow or Trunk-Based Development). Ensure smooth, efficient, predictable deployment workflows. Tech Stack Requirements Must-Have 5+ years of professional full-stack engineering experience Strong production experience with: Node.js, NestJS React.js, Next.js TypeScript Solid PostgreSQL knowledge (data modeling, optimization, indexing) Strong experience with AWS services (Lambda, S3, CloudWatch, SNS/SQS or equivalents) Experience building secure REST APIs (JWT auth, security best practices) Understanding scalable architectures and distributed systems basics Hands-on experience with CI/CD pipelines and GitHub Actions Docker experience Experience managing Git branching strategies (Git Flow / Trunk-Based Development) Ability to work hybrid in Warsaw (2–3 days/week in the office) Nice-to-Have (Strong Plus) Kubernetes (K8s) ArgoCD or GitOps workflows Event-driven systems (Kafka, RabbitMQ, AWS SNS/SQS) Infrastructure as Code (Terraform) Observability tooling (Sentry, Datadog, Groundcover) Experience with design systems / Storybook Experience with internal utilities or shared packages Experience with test automation frameworks (Playwright or similar) Key Performance Indicators (KPIs) Reliable end-to-end feature delivery Architecture clarity and maintainability Production stability & incident resolution speed CI/CD stability and deployment quality Code quality, documentation, and testing discipline What the Company Offers Competitive compensation 22 paid vacation days + national holidays Annual learning & development budget (courses, certifications, conferences) Opportunity to contribute to a fast-growing multi-product SaaS environment Modern technology stack with minimal legacy Hybrid work model with a Warsaw-based office Senior, autonomous engineering culture focused on product impact Interview Process External recruiter call (30 min) – introduction, expectations Recruiter Interview (prescreen, scorecard, expectations) Technical Interview with Thomas Goik SDE Challenge 1-day test assignment Must be submitted within 5 days Second Technical Interview with Ionel & Dima HR Interview (Professional skills, ways of working, cultural philosophy)

Responsibilities

The Senior Fullstack Engineer will take full hands-on ownership of backend and frontend feature development, contributing to architecture decisions and ensuring performance. This role involves building complex features end-to-end and maintaining code quality across a modern SaaS environment.