Principal Software Engineer - Mobile Monetization (Ad Server)

About the Role PubMatic is seeking an experienced and technically strong Principal Software Engineer to lead the design and development of next-generation Mobile App Monetization capabilities. This role is focused on building high-performance, low-latency, scalable, and privacy-safe systems that help maximize publisher revenue from in-app inventory while improving DSP and buyer spend efficiency. The role requires a deep understanding of mobile app advertising, SSP-DSP RTB workflows, OpenRTB mobile signals, SDK/mediation integrations, traffic shaping, QPS optimization, mobile attribution, privacy constraints, and performance advertising. The engineer will work on systems that monetize mobile formats such as rewarded video, interstitial, native, banner, app-open, playable, and video ads. The ideal candidate is a seasoned backend engineer with strong ad-tech domain expertise and experience building real-time auction, targeting, decisioning, and optimization systems. You will work closely with Product, Data Science, Marketplace Quality, DSP Partnerships, Publisher teams, and SRE to build ML-integrated and data-driven monetization systems that improve yield, bid rate, win rate, fill rate, attribution readiness, latency, and reliability across PubMatic’s mobile app ecosystem. What You'll Do Architect and implement scalable backend services powering mobile app monetization, extracting, transforming, and optimizing in-app behavioral data using on-device computation, data aggregation, and differential privacy techniques so that publishers can still deliver targeted ads and measure performance without accessing persistent, individual user identities. Build and optimize SSP-DSP integration workflows for mobile app inventory, including app bundle validation, device and geo signal handling, privacy-aware user signal processing, bid response handling, loss reason analysis, and DSP-specific troubleshooting. Design mobile-specific traffic shaping and QPS optimization systems that prioritize high-value in-app inventory based on bid probability, win probability, spend potential, app quality, device signals, geo value, ad format, consent availability, and DSP buying behavior. Improve runtime handling for Mobile App ad formats such as rewarded video, interstitial, native, banner, app-open, playable, and in-app video, including format eligibility, creative compatibility, response validation, tracking, completion, and reward-callback correctness. Build capabilities that improve buyer/DSP compatibility for MApp inventory, ensuring buyers receive well-represented, privacy-compliant, format-compatible, attribution-ready, and supply-quality-aware mobile app requests. Develop systems and diagnostics to improve Mobile App supply quality, including app bundle validation, app store metadata checks, app-ads.txt, sellers.json, SupplyChain object validation, app spoofing detection, invalid traffic indicators, device/geo inconsistency checks, and low-quality partner supply detection. Support privacy-aware and attribution-ready Mobile App advertising, including ATT/IDFA handling, AAID availability, consent enforcement, COPPA/child-directed treatment, SKAN readiness, MMP signal passing, click/impression tracking, and privacy-safe fallback when user-level identifiers are unavailable. Partner with MApp SDK and OpenBid/S2S integration teams to define signal-quality standards, request-field expectations, placement/ad-unit semantics, tracking requirements, and partner feedback loops for Mobile App supply. Build publisher-facing and buyer-facing diagnostics for MApp inventory, including missing-field reports, app quality signals, buyer no-bid diagnostics, fill and eCPM diagnostics, tracking mismatch analysis, attribution readiness, and supply-path quality insights. Work with DSP Partnerships and Marketplace Quality teams to improve buyer confidence in PubMatic’s MApp supply by addressing format compatibility, attribution readiness, privacy eligibility, fraud risk, su…