Senior Software Engineer – React / Node

Description

About Gapstars

About Gapstars
At Gapstars, we partner with some of Europe's most ambitious companies, from disruptive tech startups to established Benelux accounting firms, helping them build high-performing teams in engineering and finance.

Headquartered in the Netherlands, with talent hubs in Sri Lanka and Portugal, we are home to 300+ professionals who thrive on solving real-world challenges with modern solutions. Our teams work across domains, from networking, marketplaces, SaaS, and AI to embedded finance and accounting, delivering scalable solutions that drive meaningful outcomes.

The Role
We are looking for an experienced Senior Full Stack AI Engineer to build and scale critical product features across backend services, frontend applications, AI integrations, and cloud infrastructure.

This is a hands-on engineering role where you will be responsible for delivering reliable, secure, and maintainable software in a fast-moving environment. You will work closely with product, design, and engineering teams to deliver end-to-end solutions and integrate Generative AI capabilities into real-world product workflows

The Role

Senior Software Engineer - React / Node

Requirements

Key Responsibilities
 

● Develop and maintain high-performance web applications using React.js,
Node.js, and MongoDB (or other NoSQL Databases)
● Design and implement scalable, maintainable, and reusable front-end and
back-end components
● Architect, develop, and optimize RESTful APIs and backend services
● Implement authentication and security mechanisms (JWT, OAuth) to protect
application data
● Work closely with UI/UX designers to create intuitive and visually appealing
user interfaces
● Optimize application performance by implementing best practices
● Lead and mentor junior developers, conduct code reviews, and enforce coding
standards
● Conduct Unit Testing and Integration Testing using Jest to ensure software
reliability
● Work in an Agile/Scrum environment, collaborating with cross-functional
teams to deliver high-quality products on schedule
● Lead and contribute to the entire software development life-cycle, from
ideation and planning to implementation, testing, deployment, and
maintenance
● Refactor and optimize existing code base to improve performance, reliability,
and maintainability
● Take ownership of key modules or components, ensuring their stability,
security, and seamless integration with the overall system
● Collaborate closely with cross-functional teams (product, design, and other
engineering teams) to translate requirements into technical solutions

Technical Skills
 

● Expertise in React.js and its core principles (Hooks, Context API, Component
Lifecycle) and Node.js (Express.js, RESTful APIs, WebSockets, Authentication,
Performance Optimization, Asynchronous Programming, Database
Integration – NoSQL)
● Strong knowledge of JavaScript (ES6+), TypeScript, and modern front-end
development techniques
● Proficiency in Redux (or Context API) for state management
● Strong UI/UX understanding, experience with styled-components
● Experience in writing custom hooks and reusable components
● Strong experience in Node.js and Express.js
● Deep understanding of RESTful APIs and their design principles
● Expertise in authentication and security implementation (JWT, OAuth)
● Expertise in MongoDB (Schema design, Aggregation, Indexing, Projection)
● Experience in Unit Testing & Integration Testing (Jest)
● Writing clean, maintainable, and scalable code following SOLID principles
● Familiarity with Linting tools (ESLint, Prettier) and static code analysis

Experience & Qualifications
 

● 6+ years of professional experience in React.js and Node.js
● Experience in designing and architecture of scalable, maintainable, and
high-performance systems for fulfilling product requirements
● Proven experience working on complex SaaS large-scale applications
● Familiarity with Agile/Scrum methodologies

Soft Skills


● Excellent problem-solving and debugging skills
● Strong communication and leadership skills
● Ability to work in a fast-paced environment
● Strong analytical and decision-making skills

Bonus Skills (Optional)


● Experience with AI/ML implementation
● Experience working with mobile app development (React Native)

● Hands-on experience with Serverless frameworks (AWS Lambda,
Firebase Functions)

  • Perks & Benefits

    We believe taking care of our people is non-negotiable. Here's what being a Star means:

  • Wellbeing first: Comprehensive health cover, surgical & hospitalization benefits, and access to therapy & counseling services
  • Work-life essentials: 24h continuous internet and power facility, shuttle service, and a gym membership to keep you moving
  • Everyday comforts: Unlimited tea & coffee facilities along with snacks & drinks.
  • Growth, always: Personal Development Plans through Gapstars Academy, cross-functional learning via StarTalks, and opportunities for overseas travel and training
  • Life's milestones, celebrated: Birthday vouchers, wedding and childbirth gifts, anniversary treats, and more, because we celebrate our Stars at every stage
  • Community & culture: Sports clubs, company events, tournaments, and parties that make Gapstars feel like home

"Gapstars is committed to a diverse and inclusive workplace. We are an equal-opportunity employer and do not discriminate based on race, national origin, gender, disability, or age. Your personal information collected during the application process is handled following our privacy policy and used exclusively for recruitment and hiring purposes only"


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Here to help

Reach out to us, and let’s explore how we can build your dreams with the right people, expertise, and solutions.