Senior Software Engineer, Design in Test (SDET)

About the role

Senior Software Development Engineer in Test (SDET)

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.

Required Qualifications

• Minimum 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.
• Experience 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/XRay, 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 services, UI).
• Ability to document test plans, automation approaches, and defect reports with clarity and precision.
• Due to program requirements, this position requires US-born citizenship.

Preferred Qualifications

• Experience with RabbitMQ and Kafka in event-driven or message-based architectures.
• Experience coding in Go.
• Experience with secure, on-prem, or airgapped deployment environments.
• Experience with performance and load testing.
• Defense, aerospace, or government program background.
• Geospatial or remote sensing system experience.
• Experience writing integration documentation, runbooks, or system validation procedures.
• Master's degree in a relevant field of study.

Life at BlackSky

Life at BlackSky for full-time US benefits eligible employees includes:

• Medical, dental, vision, disability, group term life and AD&D, voluntary life and AD&D insurance
• BlackSky pays 100% of employee-only premiums for medical, dental and vision and contributes $100/month for out-of-pocket expenses!
• 15 days of PTO, 11 Company holidays, four Floating Holidays (pro-rated based on hire date), one day of paid volunteerism leave per year, parental leave and more
• 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
• Mac or PC? Your choice!
• Awesome swag

Pay Information

The anticipated salary range for candidates in Seattle, WA is $135,000-$155,000 per year. The final compensation package offered to a successful candidate will be dependent on specific background and education. BlackSky is a multi-state employer and this pay scale may not reflect salary ranges in other states or locations outside of Seattle, WA.