Kargo

Principal Software Engineer

Kargo$230K — $250K *
Enterprise Technology
11 - 15 years of experience
Job Overview by Ladders

Qualifications

  • 12+ years of experience with production systems in ad tech or programmatic environments
  • Expert proficiency in multiple programming languages and frameworks, particularly Go and Node.js
  • Deep knowledge of the OpenRTB protocol and real-time bidding mechanics
  • Strong skills in full-stack web architecture, including HTTP, RESTful APIs, and browser rendering
  • Familiarity with video and mobile ad standards like VAST/VPAID and MRAID
  • Proven problem-solving abilities under production pressure, with a track record of influencing technical directions.

Responsibilities

  • Own technical strategy and architecture for ad serving infrastructure
  • Deliver cross-team architectural initiatives from strategy to production
  • Set the technical direction for ad delivery, anticipating programmatic shifts
  • Become the authority on ad serving and advise engineering leadership
  • Mentor junior engineers to enhance their growth and promotion readiness
  • Drive the adoption of new technologies across multiple teams
  • Collaborate on complex projects that improve scalability and quality.

Benefits

  • Hybrid work model, requiring onsite presence 4 days a week
  • Potential for professional growth and mentoring opportunities
  • Opportunity to shape the future of ad technology
  • Engagement in strategic, high-impact projects that influence entire organization
  • Collaborative environment with a focus on continuous improvement and learning.
Full Job Description
Mission

The Principal Engineer for Surface Ad Delivery (SAD) owns the technical strategy and architecture for the ad serving infrastructure behind Kargo's programmatic platform at scale. The SAD team carries full-stack responsibility for real-time bidding, partner integrations, exclusive inventory expansion, proprietary ad formats, and delivery across web, mobile, and DOOH. When this role is firing on all cylinders, the platform is positioned ahead of industry and scaling shifts, the hardest architectural problems have a clear owner, and the team is building on patterns set years before the rest of the market catches up.

This is a hybrid role with a requirement to be onsite 4 days per week.

Outcomes - What Success Looks Like in 6-12 Months
  • Delivered a cross-team architectural initiative. Designed and shipped at least one major system or architectural change spanning multiple teams, carried from strategy through production rollout and adoption.
  • Set the technical direction for ad delivery. Anticipated industry standards, programmatic shifts, and scaling demands, and repositioned the platform ahead of the curve with measurable business impact.
  • Became the recognized authority on ad serving. Established as the org's go-to expert on SSP architecture and real-time bidding decisions, and a trusted advisor to engineering leadership on high-stakes calls.
  • Raised the technical bar across the department. Mentored Staff and Senior Engineers with measurable impact on their growth and promotion readiness, creating capability that outlasts individual projects.
  • Drove org-wide adoption of new practices. Moved new technologies, patterns, or standards from POC to production across multiple teams, improving quality, scalability, or velocity beyond a single team.

Skills - Core Technical Capabilities

Required
  • 12+ years building and maintaining production systems, with deep ad tech or programmatic experience
  • Expert across multiple languages and frameworks, including those active on the team (Go, 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: HTTP/CORS, RESTful APIs, client-side JavaScript, browser rendering, and backend services, with the judgment to architect across them
  • Working command of video and mobile ad standards (VAST/VPAID, MRAID), including debugging complex rendering and tracking issues
  • Proven ability to debug the team's toughest problems in production, and to influence technical direction across the org without direct authority

Preferred
  • Header bidding, SSP platforms, or DOOH advertising, including ad format rendering across web, mobile, and DOOH surfaces
  • Prior Staff Engineer, Tech Lead, or equivalent technical leadership role

Competencies - Behaviors We Like to See

Strategic technical leadership
  • Builds multi-year technology strategy for business-critical areas that cross multiple systems and teams
  • Makes high-stakes, long-horizon technical decisions and is trusted to balance business needs against technical excellence

Influence without authority
  • Drives adoption of new technologies and patterns through demonstration and credibility, not mandate
  • Resolves the most complex challenges that span multiple teams or product areas, and establishes standards others choose to follow

Sustained high-impact delivery
  • Carries complex, multi-team initiatives from concept to production and across the finish line
  • Ships code that's well-reasoned and tested, with a clear recovery plan when things go wrong

Developer of technical talent
  • Mentors Staff and Senior Engineers with measurable impact on their growth and promotion readiness
  • Raises the bar through code reviews, architectural guidance, and knowledge sharing that becomes a force multiplier


In accordance with applicable federal, state, and local pay transparency laws, the anticipated base salary range for this position is listed below. Actual compensation may vary based on factors such as geographic location, work experience, education, and skills.

U.S Salary Range

$230,000-$250,000 USD

About Kargo

Kargo is a mobile advertising company that specializes in delivering ads to mobile devices. The company offers a range of advertising solutions, including display ads, video ads, and native ads. Kargo works with a variety of publishers and advertisers to deliver targeted, engaging ads to mobile users. The company was founded in 2010 and is headquartered in New York City.
Learn more about Kargo
Size
200 employees
Industry
Founded
2010

Similar Jobs

More Jobs at Kargo

More Enterprise Technology Jobs

Find similar Principal Software Engineer jobs: