Senior Software Developer Jobs in Bellevue, WA

INTRODUCTION

Are you ready to revolutionize the advertising industry? At Cognitiv, we are not just another AdTech company—we are industry trailblazers redefining media buying with our Deep Learning Advertising Platform. Since 2015, we have harnessed the power of cutting-edge deep learning technology and data science to transform how brands connect with their customers. Our mission? To bring intelligence to advertising and deliver unparalleled precision, relevance, and impact at scale. With our innovative platform, advertisers enjoy unprecedented flexibility—whether it is activating Dynamic Deals through their preferred DSP, leveraging our managed service DSP, or utilizing our industry-first ContextGPT product. As a part of Cognitiv, you will be at the forefront of AI-driven advertising solutions, driving change and achieving remarkable growth in a rapidly evolving industry. Now, we’re growing!

THE ROLE

We’re hiring a Senior Software Engineer (Backend) to join the team building our next-generation, pixel-less ad targeting systems. You’ll design, build, and scale systems that power cutting-edge AI-driven advertising products, while improving and evolving existing platforms to meet growing business needs. This role is accountable for scaling our ContextGPT revenue by building and supporting system integrations that make it available to more customers, more partners, and more supply. This engineer will work closely with our internal platform teams and external partners to make ContextGPT available across the ad-tech ecosystem. This position will be located in Bellevue with a hybrid work schedule of 3 days in office (Mon/Tue/Wed) and 2 days remote optional (Thursday/Friday).

WHAT YOU’LL DO

- Design, build, and own backend services and APIs in .NET Core on AWS that power ContextGPT integrations across the ad-tech ecosystem
- Drive integrations with new data centers and third-party partners to expand inventory access and unlock new revenue streams
- Address scaling challenges as ContextGPT continues its rapid growth trajectory
- Collaborate with internal platform teams and external partners to make ContextGPT available at scale
- Take full ownership of systems end-to-end — from design through production operations
- Drive improvements in performance, reliability, and developer productivity across the team

WHO YOU ARE

- Experienced senior backend engineer: Strong in .NET Core (or a similar strongly typed language (Java, Kotlin, etc) and AWS, with a track record of designing and delivering complex production systems end-to-end
- Systems thinker: Comfortable navigating a large, multi-product codebase and reasoning across service boundaries
- Ownership, Drive & Agency: You take full responsibility for outcomes, not just tasks. You work independently, prioritize effectively, and proactively deliver high-impact results without waiting to be directed. This is the most important thing to us.
- Excellent communicator: You collaborate effectively with both internal teams and external partners, and resolve conflicts constructively
- Quality-focused: Demonstrated emphasis on testing, maintainability, and operational excellence
- Resilient & gritty: You thrive in ambiguity, manage competing priorities, and push through obstacles
- In-person collaborator: You want to work onsite MTW in Bellevue, WA

BONUS POINTS IF YOU HAVE

- Prior experience with integrations or partner-facing development
- AdTech or programmatic advertising background
- Startup experience (fast-moving, lean environments)
- Exposure to CI/CD pipelines and automated testing frameworks
- Hands-on experience with our stack: .NET Core, AWS, RDS, ClickHouse, Datadog

WHAT SUCCESS LOOKS LIKE IN YOUR FIRST 30/60/90 DAYS

What success looks like in your first 30 days:

- Ramp quickly on ContextGPT — the product, its architecture, key stakeholders, and the ad-tech ecosystem it operates in
- Build strong context on current integration patterns and the scaling challenges ahead
- Establish relationships with key internal and external partners
- Identify early opportunities to improve reliability, performance, or developer experience

What Success Looks Like In Your First 60 Days

- Begin independently owning integration development and partner-facing work
- Deliver early, measurable progress on at least one active integration or scaling initiative
- Align with stakeholders on priorities and success metrics for the next phase of ContextGPT growth
- Start influencing architectural and technical decisions

What Success Looks Like In Your First 90 Days

- Fully own one or more ContextGPT integrations or supply-expansion initiatives
- Deliver measurable business impact — new partner live, expanded inventory access, or a resolved scaling bottleneck
- Improve or scale at least one key system or process
- Operate with full autonomy as a trusted technical partner on the team

SALARY

- Salary: $160,000 - $210,000 USD Base Salary + Equity

WHAT WE OFFER

Compensation is based on experience, skills, and other factors. Base salary is just one part of your total rewards at Cognitiv—you’ll also receive equity and a comprehensive benefits package.

HIGHLIGHTS INCLUDE

- Medical, Dental and Vision plan for US employees & Extended Health Benefits for Canadian employees
- 12 weeks paid parental leave + 4 weeks WFH
- Unlimited PTO + Work-From-Anywhere August
- Career development with clear advancement paths
- Equity for all employees
- Hybrid work model & daily team lunch
- Health & wellness stipend + cell phone reimbursement
- 401(k) & RRSP with employer match
- Parking (CA, WA, Vancouver offices) & pre-tax commuter benefits
- Employee Assistance Program
- Comprehensive onboarding (Cognitiv University)
- …and more!

WHAT YOU’LL FIND AT COGNITIV

- Festiv – We make work fun with cross-team games, events, and creative team bonding.
- Responsiv – You’ll be close to clients and leadership, influencing real outcomes.
- Inclusiv – Diversity and individuality are celebrated across all levels.
- Inventiv – We reward curiosity and embrace bold ideas.
- Transformativ – We support your growth with training, mentorship, and flexibility.
- Collaborativ – We operate across coasts, connected by purpose and teamwork.

Cognitiv is proud to be an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive workplace for all.

Note on AI Use: Cognitiv may use AI technology to assist with certain administrative aspects of the hiring process, such as note-taking, interview documentation, and reporting. However, every resume and application is reviewed directly by our recruiting team. AI tools are used solely for operational support and do not influence candidate evaluation or hiring decisions.