Software Engineer (For Independent Contractors)

at Booking.com

📍 Amsterdam, Netherlands

EUR 50-100 per hour

MIDDLE

✅ Hybrid ✅ On-site

✅ Contract / Freelance

Tech Stack
Tag name is followed by "@" symbol and proficiency level value. About proficiency levels:

1-2 — basic awareness. Minimal hands-on experience, and a rudimentary understanding of the technology's purpose;

3-6 — daily use. Comfortable and regular usage, capable of handling common tasks and challenges related to the technology;

7-9 — you are an expert, you can teach others, you know all the pitfalls and tricks;

10 — exceptional knowledge, comprehensive understanding, and adeptness in all aspects of the technology, including advanced problem-solving. Think twice before claiming or demanding such level.

A/B Testing @ 3 AWS @ 1 CI/CD @ 3 CSS @ 5 Communication @ 5 Docker @ 3 Git @ 3 GraphQL @ 3 HTML @ 5 JavaScript @ 5 Kubernetes @ 3 Node.js @ 3 Performance Monitoring @ 6 Performance Optimization React @ 5 Security Swift @ 5 TypeScript @ 5 iOS @ 5

Details

We’re looking for two developers for the User Interface team at Booking.com.

Responsibilities

Gather, validate, and translate business requirements and mockups into fully functional components, pages and products.
Design and implement product features in collaboration with frontend and backend engineers, UX designers, copy writers, test engineers, and other crafts.
Write unit tests (and UI tests for iOS) and maintain/improve code quality.
Own software delivery and maintenance aspects including deployments, monitoring, scalability, security, reliability, performance optimization, troubleshooting, and support.
Apply incident response practices and use performance monitoring (and crash monitoring for iOS).
Deploy and maintain software in production environments.
Work with frontend/mobile architecture principles and best practices.

Requirements

Fullstack Developer (User Interface team)

Minimum of 4 years of experience working with JavaScript/TypeScript, React, HTML, CSS, using modern tools and methodologies.
Expert-level proficiency in frontend development.
Experience with additional technologies like GraphQL and Node.js.
Expertise in designing and implementing product features with collaboration across disciplines.
Expertise in writing unit tests.
Expertise in software delivery and maintenance aspects: deployments, monitoring, scalability, security, reliability, performance optimization, troubleshooting, and support; ability to deploy and maintain software in production environments.
Strong understanding of incident response practices; experience working with performance monitoring tools.
Experience with version control tools like Git.
Expertise in frontend architecture principles and best practices.
Expertise in cross-browser and cross-platform development, feature compatibility, responsive design, graceful degradation, and fault tolerance.
Experience working with containerized applications (Docker, Kubernetes), including deploying, scaling, managing, and troubleshooting containerized services in production environments; ability to orchestrate multi-container setups, implement CI/CD pipelines, optimize performance, and ensure high availability.
Experience with cloud-native applications (AWS) is an advantage.
Experience with data-driven product development processes, including data analytics and A/B testing.
Experience working on products impacting a large customer base is a plus.
Fluency in English with excellent written and spoken communication skills.

iOS Developer

Minimum of 4 years of experience working with Swift, SwiftUI/UIKit, iOS SDK, Xcode, and modern iOS development tools and methodologies.
Expert-level proficiency in iOS development.
Experience with additional technologies like GraphQL and backend integrations is an advantage.
Ability to gather, validate, and translate business requirements and mockups into fully functional screens, components and products for iOS applications.
Expertise in designing and implementing product features in collaboration with iOS and backend engineers, UX designers, copy writers, test engineers, and other crafts.
Expertise in writing unit tests and UI tests.
Expertise in software delivery and maintenance aspects: deployments, monitoring, scalability, security, reliability, performance optimization, troubleshooting, and support; ability to deploy and maintain software in production environments.
Strong understanding of incident response practices; experience working with performance and crash monitoring tools.
Experience with version control tools like Git.
Expertise in mobile application architecture principles and best practices.
Expertise in cross-device and cross-platform mobile development, feature compatibility, adaptive design, graceful degradation, and fault tolerance.
Experience working with containerized applications (Docker, Kubernetes), including deploying, scaling, managing, and troubleshooting containerized services in production environments; ability to orchestrate multi-container setups, implement CI/CD pipelines, optimize performance, and ensure high availability.
Experience with cloud-native applications (AWS) is an advantage.
Experience with data-driven product development processes, including data analytics and A/B testing.
Experience working on products impacting a large customer base is a plus.
Fluency in English with excellent written and spoken communication skills.