Senior Software Engineer, Creative Serving

Liftoff

Location
London, United Kingdom
Job Type
full-time
Salary
Unknown
Posted
July 27, 2025

Job Description

Liftoff is a leading AI-powered performance marketing platform for the mobile app economy. Our end-to-end technology stack helps app marketers acquire and retain high-value users, while enabling publishers to maximize revenue across programmatic and direct demand.

Liftoff’s solutions, including Accelerate, Direct, Monetize, Intelligence, and Vungle Exchange, support over 6,600 mobile businesses across 74 countries in sectors such as gaming, social, finance, ecommerce, and entertainment. Founded in 2012 and headquartered in Redwood City, CA, Liftoff has a diverse, global presence.

The Creative Serving team maintains and operates mission critical systems involved in every ad serving across Liftoff’s product line. Our systems are foundational and fundamental for Liftoff to function and thrive. As a senior staff engineer, you will build and maintain deep, strategic integration with our partner exchanges, assure impeccable uptime and drive cost effective content delivery world-wide. This includes close collaboration with our internal Vungle Exchange and SDK to help enable Liftoff Exclusive advertising capabilities. As a software engineer, you will also be a critical part of maintaining our ad serving infrastructure, working closely with peers and senior engineers. Your specific responsibilities will include:

Responsibilities:

  • Contribute to Ad Serving Architecture: Develop and maintain code that supports our ad serving architecture, ensuring reliability and performance. Participate in the on-call rotation to help troubleshoot and tackle issues as they arise.
  • Implement Cross-Functional Requirements: Work closely with other teams to understand their needs and translate those requirements into effective code solutions that integrate seamlessly with existing systems.
  • Participate in Code Reviews and Discussions: Actively engage in code reviews, contributing your insights and suggestions to improve the quality of the codebase. Take part in architectural discussions and provide valuable input into technical decisions.
  • Support Coding Standards and Best Practices: Collaborate with your team to uphold and refine coding standards, development processes, and best practices, ensuring consistency and quality in the work produced.
  • Collaborate with Peers:  Work alongside fellow engineers, sharing knowledge and supporting each other’s growth. Contribute to a positive, collaborative work environment.
  • Engage in Roadmap Planning: Participate in brainstorming and planning sessions for the product roadmap, providing feedback and suggestions that help shape the technical direction of the team.

Requirements:

  • 5+ years of software engineering experience
  • 3+ years of industry experience
  • Experience with object-oriented programming languages is required; familiarity with JavaScript, TypeScript, and Clojure is a strong plus.
  • Basic knowledge of various ad formats (e.g., display, video, native) and technologies like VAST, VPAID, and MRAID is a big plus.
  • Prior experience with mission critical systems.
  • Some knowledge of the ad tech ecosystem, real time bidding (RTB) protocol.
  • Good communicator, empathetic and focused listener.

Working at Liftoff is fast-paced, fun, and challenging, and we thrive on innovation. Come join the rocket ship and help shape the future of the mobile app ecosystem with us! 


Location:

This role is eligible for full-time work in our London hub.

Travel Expectations:

We offer several opportunities for in-person team gatherings, including but not limited to project meetings, regional meetups, and company-wide events. We expect our employees to attend these gatherings at least once per quarter. These gatherings provide essential opportunities for collaboration, communication, and team building.

Compensation:

Liftoff offers all employees a full compensation package that includes equity and health/vision/dental benefits associated with your country of residence. Base compensation will vary based on the candidate's location and experience.

🎯 Who is this job for?

This role is ideal for a Senior Software Engineer with 5+ years of experience and strong skills in object-oriented programming, ideally with JavaScript, TypeScript, or Clojure. It's best for someone familiar with mission-critical ad tech systems, RTB protocols, and various ad formats like VAST or MRAID. The position is based in London, offering impactful work on high-performance ad serving infrastructure and cross-functional collaboration.

πŸ’¬ Potential Interview Questions

  1. Describe your experience working with mission-critical systems in a high-performance environment.
    Built and maintained low-latency, fault-tolerant services for ad delivery with 99.99% uptime SLAs using scalable infrastructure and robust observability tools.

  2. How do you ensure high availability and performance in ad-serving architecture?
    Implement horizontal scaling, CDN caching, load balancing, and retry mechanisms; monitor with Prometheus/Grafana and conduct chaos testing.

  3. What experience do you have with VAST, VPAID, or MRAID ad technologies?
    Implemented support for VAST-compliant video ads, integrated MRAID into mobile SDKs, and debugged VPAID JavaScript creatives for display campaigns.

  4. How do you approach integrating with external ad exchanges using RTB protocols?
    Understand OpenRTB specs, validate bid requests/responses, ensure timeouts under 100ms, and test extensively in sandbox environments.

  5. How do you contribute to architectural discussions in cross-functional engineering teams?
    Bring clear tradeoffs, use diagrams (e.g., C4 model), align on scalability/security, and factor in feedback from backend, frontend, and DevOps engineers.

  6. Share your experience with object-oriented languages, specifically JavaScript, TypeScript, or Clojure.
    Built ad-serving components in TypeScript (Node.js), contributed to frontend tools in React, and refactored legacy services in Clojure to improve testability.

  7. What tools or practices do you use for troubleshooting complex issues in production systems?
    Use distributed tracing (OpenTelemetry), structured logging, and metrics; reproduce issues in staging; and run post-mortems to document learnings.

  8. Describe a situation where you improved codebase quality through code reviews or refactoring.
    Introduced ESLint and pre-commit hooks, migrated a legacy module to modular TypeScript with interfaces, and mentored team on clean code practices.

  9. How do you stay aligned with cross-functional requirements from other engineering teams?
    Attend planning syncs, use shared RFCs for cross-team initiatives, maintain integration tests, and document interfaces in internal wikis.

  10. Why are you interested in Liftoff’s Creative Serving team and the ad tech space?
    Fascinated by the scale and complexity of real-time ad systems, excited to optimize creative delivery and work on foundational tech critical to revenue.

πŸ“‹ Job Summary

Liftoff is hiring a Senior Software Engineer in London to work on mission-critical ad serving infrastructure as part of their Creative Serving team. You'll design and maintain high-performance systems that enable global ad delivery, collaborating closely with exchange and SDK teams. Ideal candidates have 5+ years of experience, proficiency in object-oriented programming (JavaScript, TypeScript, or Clojure a plus), and knowledge of ad tech and RTB protocols. Enjoy working in a fast-paced, innovative environment with equity, comprehensive benefits, and quarterly team meetups.

Required Skills

JavaScript TypeScript

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