Senior Software Engineer, Design in Test (SDET)

BlackSky•Tukwila, WA

4d•$145,000 - $165,000•Hybrid

About The Position

BlackSky is hiring a development-focused Software Development Engineer in Test (SDET) to build automated test frameworks, tools, and simulated environments that ensure the reliability and quality of enterprise software systems. The role focuses on creating test harnesses, emulating third-party systems and network conditions, and developing reusable automation infrastructure for comprehensive in-house validation. The SDET will create Python-based frameworks, service and API simulators, and automation that integrates with CI/CD pipelines to provide consistent test coverage across complex application workflows. The position also involves analyzing system behavior, investigating failures, collaborating with developers, and validating fixes to improve product stability and release confidence. The preferred location is Tukwila, Washington, with work in the Tukwila office one to two days per week; strong remote candidates may also be considered. The anticipated salary range for candidates in Seattle, Washington, is $145,000–$165,000 per year. Final compensation depends on the candidate’s background and education, and the stated range may not apply to other locations. The role requires U.S. citizenship due to program requirements. BlackSky states that it is an equal opportunity employer.

Requirements

At least six years of experience as a Software Test Engineer, Automation Engineer, or SDET, with significant hands-on software development responsibilities.
Bachelor’s degree in a relevant field of study, or equivalent additional experience of four years.
Strong proficiency in Python, including writing reusable modules, building automation frameworks, and creating test harnesses or tools.
Experience developing automated API tests using Python Requests or equivalent frameworks.
Experience designing and maintaining automated UI tests; Python Playwright is preferred, with emphasis on code structure and maintainability.
Experience building Python-based utilities, simulators, mocks, or environment emulators for complex test scenarios.
Familiarity with reporting test results and integrating automation with Jira/X-Ray, Slack, or similar tools.
Ability to analyze automated test results, identify root causes across services and layers, and validate fixes with developers.
Working knowledge of CI-based automated test pipelines, nightly execution workflows, and test orchestration.
Understanding of distributed systems, API-driven architectures, and service interactions.
Strong troubleshooting and debugging skills across APIs, backend services, and UI layers.
Ability to clearly document test plans, automation approaches, and defect reports.
U.S. citizenship is required due to program requirements.

Nice To Haves

Experience with Postman/Newman.
Experience testing and verifying embedded software.
Experience building or maintaining hardware for embedded software testing.
Experience programming in Python.
Experience programming in C/C++.
Ability to debug C/C++ and perform fault analysis.
Experience maintaining CI/CD systems or infrastructure as code.
Experience with QEMU and device emulation.
Experience with Buildroot or Yocto.

Responsibilities

Design, develop, and maintain automated test frameworks and tools using Python for testing services, APIs, and UI workflows.
Build Python- or Go-based simulators, mocks, and emulators for third-party environments, network behavior, and integration scenarios.
Develop, maintain, and execute automated API test suites using Python Requests, custom harnesses, and, when appropriate, Postman/Newman.
Build and maintain automated UI test suites using Python Playwright, with reusable components, selectors, and page-object patterns.
Monitor nightly automated test runs, analyze failures, and provide actionable insights through Jira/X-Ray, Slack, and CI/CD integrations.
Troubleshoot issues across APIs, backend services, and UI workflows; collaborate with developers to identify root causes and verify fixes.
Perform targeted manual testing for new features, complex regression scenarios, and defect reproduction when automation is not feasible.
Validate functional behavior, edge cases, and system workflows across distributed application components.
Document test frameworks, automation patterns, test cases, expected outcomes, and defect reproduction steps.
Support and improve internal Python-based test applications, tools, and services used in verification workflows.
Ensure adequate test coverage for new features, releases, and high-risk areas.
Improve automation tooling, coding standards, and test strategy.
Assist in ensuring builds are ready for deployment and release.
Perform other job-related duties as assigned.

Benefits

Medical, dental, vision, disability, group term life and AD&D, and voluntary life and AD&D insurance.
BlackSky pays 100% of employee-only medical, dental, and vision premiums and contributes $100 per month toward out-of-pocket expenses.
15 days of PTO, 11 company holidays, and four floating holidays, prorated based on hire date.
One day of paid volunteer leave per year.
Parental leave.
401(k) pre-tax and Roth deferral options with employer match.
Flexible Spending Accounts.
Employee Stock Purchase Program.
Employee Assistance and Travel Assistance Programs.
Employer matching donations.
Professional development.
Choice of Mac or PC.
Company swag.