Senior Software Engineer, Agentic Marketplace

About Scope3 Scope3 operates the Interchange for agent-to-agent advertising — the place where brands and their agents discover, negotiate, and transact across every advertising surface that matters: social, CTV, audio, AI interfaces, sponsored intelligence, and those still emerging. Built on AdCP, the open protocol for agentic advertising, with governance, transparent pricing, and full auditability built into every transaction. Scope3 works with leading advertisers, agencies, publishers, and platforms globally, with teams across North America, Europe, and APAC. We’re a venture-backed company of 65 fully remote team members and are fortunate to be led by an experienced leadership team, many of whom designed and engineered the digital advertising landscape as we know it today. About the Role We’re building the future of programmatic advertising through AI agents. Our Agentic Marketplace team is creating the infrastructure that enables AI agents to discover, negotiate, and transact media inventory autonomously. As a Senior Software Engineer, you’ll play a key role in building the core systems that power our agentic advertising platform. You’ll develop APIs, agent interfaces, and transaction systems that support both human users and AI agents as first-class participants. You’ll work at the intersection of advertising technology, distributed systems, and emerging AI agent frameworks—helping translate architectural vision into scalable, production-ready systems. This is a Fullstack (80/20 backend leaning), hands-on role. You’ll write production code, contribute to system design, and collaborate closely with a small, senior team to bring new agent-driven capabilities to life. This isn’t a typical engineering role We’re operating in a space without a fixed playbook, so this role is best suited for builders who are comfortable creating structure where none exists.Our approach favors rapid experimentation over upfront perfection—we test, learn, and then formalize what works.The pace is fast and often pushes beyond what feels comfortable. For the right person, that’s part of the appeal.We’re also looking for engineers who are already actively exploring AI—this isn’t a “learn it on the job” environment. Responsibilities Build and maintain scalable APIs for both human and AI agent clientsContribute to the development of agent interfaces, MCP servers, and A2A communication layersImplement systems that support real-time advertising transactions at scalePartner with Staff engineers to design robust, extensible architecturesCollaborate with product and design to develop clear, agent-friendly API contractsIntegrate and experiment with emerging agent frameworks and protocolsParticipate in design reviews and provide thoughtful technical inputWrite high-quality, maintainable code and improve system reliabilityIdentify edge cases in agent behavior and help design safeguards Qualifications 5+ years of experience building backend or fullstack systemsStrong experience with API development (REST or event-driven systems)Proficiency in TypeScript/Node.js and ReactExperience working with cloud platforms (GCP or AWS)Familiarity with distributed systems concepts (scalability, reliability, observability)Interest in or exposure to AI agent systems, LLMs, or autonomous workflowsAbility to collaborate effectively in a small, fast-moving teamStrong problem-solving skills and attention to detail Nice to have: Experience with MCP, A2A, or similar communication protocolsBackground in advertising technology or marketplace platformsExperience building systems with real-time or high-throughput requirements Tech Stack API Layer: TypeScript/Node.js, REST and event-driven servicesAgent Interfaces: MCP servers and A2A protocol handlersData: PostgreSQL, BigQuery, Cloud Storage, Redis Compensation The salary range for this role is $130k-$190k USD; $140k-$200k CAD. These ranges span multiple location-based salary bands across the US and Canada. Candidates are aligned to a narrower range based on geographic market compensation data, and final offers reflect demonstrated skills, experience, and role expectations. Benefits & Perks Details vary by location (USA/Canada), but all employees receive: Health & wellness: Comprehensive medical, dental, and vision coverage with significant employer contribution; short- and long-term disability coverage; health savings/flexible spending optionsRetirement: Employer-matched retirement savings plan (401(k) or RRSP)Time off: Generous paid time off, statutory holidays, and year-end office closureParental leave: 13 weeks fully paid (eligibility requirements apply)Equity: Stock options A Note To Applicants We believe that all people are capable of great things. We encourage you to apply even if you do not meet all of the requirements that are listed within this job description. Locations: Remote (Canada); Remote (United States)