Principal Software Engineer

What you'll do

• Own technical strategy and architecture for ad serving infrastructure behind Kargo's programmatic platform
• Deliver cross-team architectural initiatives spanning multiple teams
• Set technical direction for ad delivery anticipating industry standards and scaling demands
• Become recognized authority on SSP architecture and real-time bidding decisions
• Mentor Staff and Senior Engineers to raise technical bar and promote growth
• Drive org-wide adoption of new technologies, patterns, or standards from POC to production
• Build multi-year technology strategy for business-critical areas crossing multiple systems and teams
• Make high-stakes, long-horizon technical decisions balancing business needs and technical excellence
• Drive adoption of new technologies and patterns through demonstration and credibility
• Resolve complex challenges spanning multiple teams or product areas and establish standards
• Carry complex multi-team initiatives from concept to production
• Ship well-reasoned and tested code with clear recovery plans
• Mentor technical talent through code reviews, architectural guidance, and knowledge sharing

Requirements

• 12+ years building and maintaining production systems, with deep ad tech or programmatic experience
• Expert across multiple languages and frameworks, including Go and Node.js
• Deep expertise in the OpenRTB protocol and real-time bidding
• Proven track record designing SSP/DSP integrations, bid adapters, or programmatic platforms at scale
• Strong full-stack web architecture knowledge: HTTP/CORS, RESTful APIs, client-side JavaScript, browser rendering, and backend services
• Working command of video and mobile ad standards (VAST/VPAID, MRAID), including debugging complex rendering and tracking issues
• Proven ability to debug tough production problems and influence technical direction without direct authority
• Preferred: experience with header bidding, SSP platforms, or DOOH advertising
• Preferred: prior Staff Engineer, Tech Lead, or equivalent technical leadership role

Tech stack