Senior/Lead JavaScript Developer

JavaScript

Senior/Lead JavaScript Developer

JavaScript
Prosta 20, Warszawa

Spyrosoft

Full-time
B2B
Senior
Hybrid
7 769.42 - 9 182.04 USD
Net per month - B2B

Job description

Join our team in Warsaw, where we’re collaborating on a cutting-edge fintech venture with a global industry leader. Together with our Partner – Klarna, we’re building an IT hub designed to drive innovation in digital payment solutions. We’re on the lookout for top-tier engineers who thrive in dynamic, forward-thinking environments. Spyrosoft is leading the recruitment process, facilitating a seamless experience for candidates who are ready to shape the future of online shopping and payments.


This opportunity is ideal for engineers who value independence, proactiveness, and flexibility. Our engagement begins with a B2B contract through Spyrosoft, transitioning to a direct contract with our Partner.


We offer a hybrid work model in Warsaw’s vibrant Wola district, with 3 days in the office each week. English fluency and eligibility to work in Poland are essential, as is the successful completion of a background check to meet the rigorous standards of the financial domain.


Our process:

  1. CV selection

  2. Initial recruitment screening

  3. Technical interview

  4. Online logic test

  5. Cultural fit interview



Requirements:

  1. Minimum 5 years of experience in JavaScript/TypeScript

  2. Proficiency with React.js (front-end) and Node.js (back-end), Redux (state management), Context API, Hooks

  3. CI/CD experience, experience with npm or yarn, familiarity with Webpack, Babel

  4. Experience with NoSQL databases (MongoDB, Firebase), SQL, handling databases in backend systems using Node.js

  5. Familiarity with serverless architecture (e.g. AWS)

  6. Frontend: Focus on scalability, performance, state management, and API integration in React.js

  7. Backend: Focus on designing scalable, event-driven systems with Node.js

  8. Discuss approach to debugging, refactoring, and writing clean, testable code

  9. Experience with AWS services and cloud infrastructure

Tech stack

    TypeScript

    advanced

    Node.js

    advanced

    Redux

    advanced

    React

    advanced

    JavaScript

    advanced

    AWS

    regular

    SQL

    regular

    Webpack

    regular

    Yarn

    regular

    NoSQL

    regular

Office location

Published: 28.02.2026

About the company

Spyrosoft

Spyrosoft is a leading technology company specializing in software development and IT services. The company provides a wide range of expertise including artificial intelligence, cloud services, cybersecurity, digital pro...

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