Senior Software Engineer

Microsoft

Microsoft

Software Engineering
Czechia
Posted on Dec 16, 2025
Overview

COSMIC (Containers on Substrate-Managed Intelligent Clusters) is at the forefront of innovation within the Microsoft 365 organization. It is a cutting-edge, Kubernetes-based platform designed to orchestrate containerized workloads, delivering scalability, resilience, and efficiency on a global scale. Joining COSMIC means working on technology that powers the backbone of modern collaboration and productivity (e.g., M365, Copilot, and more), helping to shape the future of distributed systems.

As a Senior Software Engineer on the COSMIC Engineering Excellence team, you will play a key role in designing and building features that extend the functionality of our platform and its testing and validation ecosystems — taking engineering quality to new heights. You will work extensively with Microsoft Azure technologies and industry-standard open-source solutions, including Kubernetes, Linux, Go, and more. You will also have opportunities to collaborate with several teams across Microsoft and make a significant impact on hundreds of critical Microsoft services running on the COSMIC platform. This opportunity will enable you to accelerate your career growth, deepen your technical expertise, and hone your ability to iterate quickly in a fast-paced environment.

Microsoft's mission is to empower every person and every organization on the planet to achieve more. As employees, we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond.



Responsibilities
  • Develop best-in-class engineering for our services by ensuring that services and components are well-defined, secure, reliable, diagnosable, actively monitored, and reusable.
  • Drive research and identification of poorly tested components; propose improvements to test coverage and lead the implementation of integration tests for problem areas.
  • Identify dependencies and user requirements, then produce architecture and design proposals.
  • Follow a data-driven approach prioritizing high impact.
  • Leverage subject matter expertise and collaborate with appropriate stakeholders to drive your group's projects, release plans, and work items.
  • Proactively seek new knowledge and adapt to new trends, technical solutions, and patterns that will improve the availability, reliability, efficiency, observability, and performance of our services, while also driving consistency in monitoring and operations at scale.
  • Act as a Designated Responsible Individual (DRI), guiding other engineers by developing and following a playbook, working on-call to monitor systems for degradation or interruptions, alerting stakeholders about status changes, and initiating actions to restore systems appropriately.
  • Champion a culture of inclusion, innovation, and accountability, embodying Microsoft's leadership principles: Create Clarity, Generate Energy, Deliver Success.


Qualifications

Required Qualifications:

  • Bachelor's Degree in Computer Science or related technical field AND extensive technical engineering experience with coding in languages including, but not limited to, Go, C++, C#, Java, or Python
    • OR equivalent experience.
  • Experience with DevOps culture and maintaining cloud services; your customers will be fellow software engineers.
  • Extensive experience with engineering systems and building CI/CD solutions.
Preferred Qualifications:
  • A self-starting problem-solver who thrives on resolving complex challenges through independent research and experimentation.
  • Azure cloud experience is highly desirable.

Other Requirements:

Ability to meet Microsoft, customer and/or government security screening requirements are required for this role. These requirements include but are not limited to the following specialized security screenings:

  • Microsoft Cloud Background Check: This position will be required to pass the Microsoft Cloud background check upon hire/transfer and every two years thereafter.
#COSMIC #M365Core #M365COSMIC

This position will be open for a minimum of 5 days, with applications accepted on an ongoing basis until the position is filled.




Microsoft is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, citizenship, color, family or medical care leave, gender identity or expression, genetic information, immigration status, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran or military status, race, ethnicity, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable local laws, regulations and ordinances. If you need assistance with religious accommodations and/or a reasonable accommodation due to a disability during the application process, read more about requesting accommodations.