Senior Software Engineer (For Independent Contractors)

EUR 60-120 per hour
SENIOR
✅ Hybrid ✅ On-site
✅ Contract / Freelance

Used Tools & Technologies

Not specified

Required Skills & Competences

Security @ 4 Docker @ 4 Kubernetes @ 4 Python @ 1 Java @ 4 CI/CD @ 4 AWS @ 4 Communication @ 4 Experimentation @ 4 Design Patterns @ 4 AI @ 4

Details

A Senior Software Engineer I owns the execution of technical elements in the Booking.com tech stack, products and processes. They are responsible for the implementation of technical solutions based on business requirements, they can estimate the effort and impact of the items they work on, and show a high quality of craft in what they deliver.

A Senior Software Engineer I understands the quality of test automation is as important as the production code and spends time refactoring both to ensure ease of change enabling a sustainable pace of development.

Senior Software Engineer I is expected to work together with colleagues in other job roles to design, prioritise and implement technical tasks. Because the required technical skills and commercial knowledge can vary from one business unit to another, a Senior Software Engineer I can focus on multiple types of work from product features to infrastructure automation, frameworks, tooling or services.

Job details

  • Project ID: 12365-1
  • Location: Amsterdam, NH
  • Hours/week: 40 hrs/week
  • Timeline: 7 months (Starts: Jun 2, 2026 — Ends: Dec 31, 2026)
  • Payrate range: 60 - 120 €/hr

Responsibilities

  • Build software applications using relevant development languages and appropriate systems, services and tools for the business area.
  • Write readable and reusable code by applying standard patterns and libraries.
  • Refactor and simplify code, introducing design patterns when necessary.
  • Ensure application quality by following standard testing techniques and methods that adhere to the test strategy.
  • Maintain data security, integrity and quality by following company standards and best practices.
  • Own services end-to-end: monitor application health and performance, set and monitor metrics and act when violated.
  • Reduce business continuity risks and bus factor by applying state-of-the-art practices and tools and writing documentation such as runbooks and OpDocs.
  • Use continuous delivery and experimentation frameworks to reduce risk and obtain customer feedback.
  • Manage application deployment and operations in production.
  • Address and resolve live production issues, mitigating customer impact within SLA.
  • Improve reliability through root cause analysis and contribute to postmortem processes.
  • Provide architectural guidance by advising product teams towards solutions that meet functional, nonfunctional and architectural requirements.
  • Evaluate architecture solutions considering cost, business and technology requirements and describe implications of system changes.
  • Apply engineering techniques (prototyping, spiking, vendor evaluation) to grow the business or accelerate development.
  • Identify and design process, system and structural improvements.
  • Deliver clear, well-structured communication tailored to the audience and collaborate to reach mutually agreeable solutions.

Requirements / Required tech stack and knowledge

  • Building AI workflows
  • Kubernetes
  • Docker
  • AWS
  • Java
  • Python is an advantage

Additional skills emphasized

  • Test automation and refactoring
  • Continuous delivery / CI/CD
  • Monitoring application health and metrics
  • Incident management and postmortem contribution
  • System design and architectural evaluation
  • Strong critical thinking and effective communication