OnHiresSenior Fullstack (Node.js + React.js)
Location: Remote
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.
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)
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
Senior, autonomous engineering culture focused on product impact
Interview Process
External recruiter call (30 min) – introduction, expectations
Recruiter Interview (prescreen, scorecard, expectations)
Technical Interview
SDE Challenge
1-day test assignment
Must be submitted within 5 days
Second Technical Interview
HR Interview (Professional skills, ways of working, cultural philosophy)