Staff Software Engineer, Ads

Whatnot•Krakow, New York

21h•$245,000 - $290,000•Hybrid

About The Position

Ads is a growing engineering team dedicated to building the systems that help Whatnot sellers grow their businesses. Our products operate at the intersection of marketplace dynamics, auction mechanics, ranking, and distributed systems. As an engineer on the Ads team, you will shape the technical foundation of Whatnot’s advertising marketplace. You’ll design auction systems that allocate limited buyer attention across sellers, balance marketplace and customer outcomes, and operate reliably at Whatnot’s scale. This includes bidding, pricing, pacing, ranking, forecasting, and real-time decision-making. This role requires strong technical judgment, comfort navigating ambiguous domains, and the autonomy to lead foundational projects from inception through production. You’ll work closely with product, machine learning, and infrastructure teams to make sound trade-offs and ship high-impact systems quickly without compromising quality.

Requirements

Bachelor’s degree in Computer Science, a related field, or equivalent work experience
8+ years (for Staff) or 10+ years (for Senior Staff) of backend/distributed systems engineering experience.
Strong mastery of distributed systems fundamentals: consensus, partitioning, replication, coordination, sharding, state management, etc.
Deep experience with high-throughput, low-latency services and stream processing (e.g., Kafka, Flink, etc.).
Strong software design, algorithmic, and data-structure skills.
Proficiency in one or more languages (e.g., Python, Go) and scripting.
Experience with messaging, caches (e.g., Redis, RocksDB), time-series stores, and data pipelines.
Proven track record of leading architecture and scaling core systems under high load, especially in an ads, ranking, or ML serving context.
Excellent communication skills, ability to influence cross-organizational stakeholders.
Proven track record of delivering features end-to-end and can ship products and features lightning-fast without sacrificing quality.
Strong ownership instincts — capable of driving projects from inception to production and beyond.
The ability to pick up on new technologies very quickly.

Nice To Haves

Startup experience at a high-growth company — working in fast-paced, rapidly evolving product environments with frequent experimentation
Experience with ads systems (bidding, auction, attribution, measurement, etc.), infrastructure, and international commerce

Responsibilities

Architect and lead the implementation of high-throughput, low-latency backend systems that power ad auctions, bidding, pacing, ranking, and delivery.
Design auction mechanisms that balance seller value, buyer experience, marketplace efficiency, and long-term ecosystem health.
Build foundational services for budget management, allocation, forecasting, experimentation, attribution, and measurement.
Develop reliable integrations between real-time auction services, machine learning models, data pipelines, and marketplace systems.
Own the performance, resilience, observability, and scalability of critical services throughout their production lifecycle.
Define service contracts, architectural patterns, fault-isolation strategies, and capacity plans for systems used by multiple product teams.
Lead technical decisions for new auction and monetization capabilities, including how experiments graduate into durable platform infrastructure.
Partner with product and machine learning teams to translate marketplace problems into practical backend and algorithmic solutions.
Lead design and code reviews, mentor senior engineers, and raise the engineering bar across system design, testing, deployment, and operations.
Participate in incident response, root-cause analysis, and postmortems for critical production systems.
Develop the technical roadmap for auction infrastructure and connect foundational investments to measurable seller, buyer, and marketplace outcomes.

Benefits

Generous Holiday and Time off Policy
Health Insurance options including Medical, Dental, Vision
Work From Home Support
Home office setup allowance
Monthly allowance for cell phone and internet
Care benefits
Monthly allowance for wellness
Annual allowance towards Childcare
Lifetime benefit for family planning, such as adoption or fertility expenses
Retirement; 401k offering for Traditional and Roth accounts in the US (employer match up to 4% of base salary) and Pension plans internationally
Monthly allowance to dogfood the app
16 weeks of paid parental leave + one month gradual return to work company leave allowances run concurrently with country leave requirements which take precedence.