Senior Software Engineer, Design in Test (SDET)

blacksky; United States; Hybrid; USD 120,000 - 160,000; Full time

Job summary

BlackSky is seeking a Senior Software Test Engineer to design and implement automated test frameworks and simulators in Python, aiding CI/CD across enterprise systems. The role emphasizes building API/UI test suites, analyzing failures, and collaborating with developers to ensure release confidence.

The preferred location is Tukwila, WA with 1-2 days in the office; strong remote candidates may be considered. This is a hands-on development role requiring 6+ years of experience.

Qualifications

• Six or more years in software testing, automation, or SDET with hands-on development.
• Strong Python expertise, including reusable modules and test harnesses.
• Experience building API tests with Python Requests and Postman/Newman.
• Experience designing automated UI tests with Playwright and maintainable code.
• Familiarity with CI-based pipelines and test orchestration.
• Ability to analyze test results and collaborate with developers.

Responsibilities

• Design, develop, and maintain automated test frameworks and tools using Python.
• Build simulators, mocks, and emulators to replicate third-party environments.
• Develop automated API tests and UI tests for end-to-end coverage.
• Monitor nightly test runs and provide actionable insights via CI/CD integrations.
• Troubleshoot failures across APIs, backend, and UI layers with developers.
• Perform targeted manual testing for new features and complex scenarios.
• Document frameworks, patterns, tests, and reproduction steps for defects.
• Support internal Python-based test tools and improve test tooling.

Skills

Python

Automated testing

CI/CD

API testing

UI testing

Playwright

Test frameworks

Jira/X-Ray

Education

Bachelor's degree in CS or related

Tools

Postman

Newman

Jira

X-Ray

Slack

Job description

Senior Software Test Engineer

About Us:

BlackSky is a real-time intelligence company. We own and operate the world's most advanced space-based intelligence platform and provide customers satellite imagery, automated analytics and high-frequency monitoring of strategic locations, economic assets and events from around the globe. BlackSky is trusted by the most demanding allied military and intelligence organizations and commercial companies to deliver foresight into critical matters that affect national security and the economy. BlackSky's data enables governments and businesses to see, understand and anticipate change as it happens, giving them the ultimate strategic advantage so they can act quickly. Our global team works with cutting-edge technology to make a difference around the world and prides itself on being people-first, customer-focused and fun.

The Software Development Engineer in Test (SDET) is responsible for designing and implementing automated test frameworks, tools, and simulated environments that ensure the reliability and quality of our enterprise software systems. This role is development-focused and centers on building test harnesses, emulating third-party systems and network conditions, and creating robust automation infrastructure that enables comprehensive in-house validation. The SDET develops reusable test code, service/API simulators, and scalable Python-based frameworks that integrate into CI/CD pipelines to deliver consistent and repeatable coverage across complex application workflows. In addition to building automation systems, they analyze system behavior, investigate failures, collaborate closely with developers, and validate fixes to drive overall product stability and release confidence.

The preferred location is Tukwila, WA with the ability to work in the Tukwila office 1-2 days a week but we may be open to strong remote candidates.

Responsibilities:

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

Required Qualifications:

• Minimum of years of six (6) years of experience as a Software Test Engineer, Automation Engineer, or SDET, with significant hands-on software development responsibilities.
• Bachelor's degree in 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.
• E xperience developing automated API tests using Python Requests or equivalent frameworks; experience with Postman/Newman preferred.
• Experience designing and maintaining automated UI tests (Python Playwright preferred), with emphasis on code structure and maintainability.
• Experience building Python-based utilities, simulators, mocks, or environment emulators to support complex test scenarios.
• Familiarity with reporting test results and integrating automation with Jira/X-Ray, Slack, or similar tools.
• Strong ability to analyze automated test results, identify root causes across services and layers, and validate fixes in collaboration 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 application layers (API, backend