Sr. Software Test Engineer - Milpitas, CA, United States
$110,000 - $155,000 USD yearly
Originally posted 14 October 2026 by the employer.
This role focuses on ensuring software and system quality for new free-space and fiber-based laser systems.
About the role
As a Sr. Software Test Engineer at MKS Instruments, you will ensure software and system quality for new free-space and fiber-based laser systems.
What you'll do
- Develop, maintain, and execute test plans and test cases (manual and automated) for embedded firmware, covering features, integration, and system levels.
- Validate GUIs for usability, functionality, responsiveness, and compatibility with target hardware and operating systems.
- Ensure software runs efficiently on embedded platforms and integrates well with hardware, firmware, and photonics modules.
- Document defects, trace them back to requirements, and work with developers to fix issues.
- Use automated testing tools for regression testing, functional testing, and GUI validation.
- Reproduce, troubleshoot, and thoroughly test field-reported and customer-facing bugs in live or simulated environments.
What you'll need
- BS degree in Software Engineering, Computer Engineering, Electrical Engineering, or equivalent.
- 5+ years related Software QA experience with embedded systems and GUIs.
- Proficiency programming in C/C# and Python.
- Experience with testing frameworks like Unity, Pytest, GTest, NUnit, xUnit.
- Familiarity with CI/CD tools, version control, and bug tracking systems like JIRA.
- Familiarity with interfaces such as I2C, SPI, RS-232, RS-485, Ethernet, and USB.
- Experience with test equipment (DVM, Power Supply, Oscilloscopes).
Nice to have
- Exposure to DevSecOps and cyber security principles.
- Experience using LLMs or other AI tools for tasks like test case generation, test data creation, and defect analysis.
- Ability to read electronic schematic diagrams and component datasheets.
- Experience with Real-Time Operating Systems (Azure/Threadx, FreeRTOS), and/or Linux.
Skills: Software QA, embedded systems, GUIs, automated testing tools, C/C# and Python
This role has been open 0 days — well below the 48-day median for Software Engineering Semiconductor roles.
Software Engineering Semiconductor · Systems Software
|
Open roles in category
360
|
Median days open
48 d
|
Median salary
$148k
|
See the full market breakdown ▾Category comparison, skills in demand, and who else is hiring
| Metric | MKS Instruments | All employers we track in this specialty (360 roles · 57 employers) |
|---|---|---|
| Open roles in this specialty | 1 | 360 |
| Open roles in the wider Software, Firmware & Systems family | 19 | 6164 · 146 employers |
| Median days open | 0 d | 48 d (−48 d vs this employer) |
| Median salary (USD postings) | — | $148k |
Skills observed across this category: Software QA, embedded systems, GUIs, automated testing tools, C/C# and Python
Who's hiring in this category
- Keysight Technologies · 38 open roles · median 27 d
- KLA Corporation · 30 open roles · median 142 d
- Cadence Design Systems · 29 open roles · median 203 d
- NVIDIA · 28 open roles · median 41 d
- Micron Technology · 27 open roles · median 40 d
- Applied Materials · 24 open roles · median 47 d
How we counted: 360 open Software Engineering Semiconductor (Systems Software) roles from 57 employers tracked in the SemiconductorJobs index, counted 14 Oct 2026. Specialty figures count only roles carrying this exact specialty label, so an employer's related work in neighbouring specialties is not included there — it is counted in the wider Software, Firmware & Systems family row. Figures refresh nightly.