Backend Engineer, Ads Recommendation System

The opportunity

Offerwall by Unity is a leading mobile advertising and monetization platform that helps game developers maximize revenue and engage users through rewarded experiences. For over a decade, we've connected millions of players with offers that provide tangible in-app value, and we're now building the next generation of that product.

At the center of it is Offer Delivery, the backend service that decides which offer a player sees, when, and on what terms. It operates on two fronts: bidding in real time as a DSP into multiformat full-screen auctions, and retrieves input features, calls our ML ranking models, and applies targeting, pacing, and supply-side rules to choose what offers gets shown.

We're seeking a Staff Backend Engineer to be the technical leader for Offer Delivery. You will set the technical vision, define the architecture, influence the roadmap, and drive delivery, owning how targeting, pacing, and supply-side rules are enforced on the serving path.

This is a meaningful role at the intersection of recommender systems, rewarded advertising, fraud prevention, and large-scale data processing.

You'll work with frontier AI tools and workflows, including Claude, Codex, and LiteLLM.What you'll be doing

Architect & Design:
Set the technical direction for Offer Delivery, owning the architecture of its services and leading design on its most critical initiatives.

Build & Ship:
Build, test, and ship the Golang and Java services that decide which offer each player sees, across real-time bidding into display auctions (OpenRTB) and direct placement outside the auction flow.

Evolve the Recommender:
Work with the ML modeling team to take ranking improvements from idea to production, covering feature retrieval, scoring data, model serving integration, and online experiments.

Lead Across Teams:
Offer Delivery sits between the auction, ML, platform, and product teams. Align them on shared decisions and drive delivery across team boundaries.

Operate at Scale:
Ensure the high availability and reliability of our production services, including on-call rotations and proactive system monitoring.

Raise the Bar:
Mentor engineers, set engineering standards, and lead by example on code and design quality.

What we're looking for Technical Leadership:
Track record of owning a significant backend system, setting direction, making the architectural calls, and getting it delivered through others as well as yourself.

High-scale distributed systems:
Demonstrated ability to design and ship large-scale, highly available, latency-sensitive distributed services with complex business logic.

Core Technologies:
Strong proficiency in backend development using Go or Java (or clear ability to become effective in Go quickly). Working knowledge of gRPC with a willingness to adapt to the best tool for the job.

Observability & Data Streaming:
Practical experience with observability platforms (logging, metrics, monitoring/tracing) and message bus technologies for managing complex data streams.

Integration Design:
Track record of building new systems amid rapidly shifting requirements. You can design systems that are stable through three requirement changes, and you know which change should revise the core data flow.

Cross-team influence & mentorship:
Experience driving technical work across team boundaries and developing the engineers around you.

You might also have Experience building recommender systems, marketplace matching, or ads ranking systems in production.

Experience building or operating a DSP, ad exchange, or real-time bidding system, with familiarity with OpenRTB, auction mechanics, or programmatic advertising.

Working understanding of supply-side ad mediation, such as waterfall vs. bidding and adapter and SDK integratio

Additional information:

Zone A: $200,400 - $260,500

Zone B: $178,300 - $231,800

Zone C: $157,800 - $205,200

This range reflects the anticipated base salary for this position. Beyond base salary, this role may be eligible for equity awards and participation in our company incentive plans (such as annual discretionary bonuses or sales commissions). The final offer amount will depend on several factors, including geographic location and the candidate’s relevant experience, professional background, and skill set.

This range reflects the anticipated base salary for this position. Beyond base salary, this role may be eligible for equity awards and participation in our company incentive plans (such as annual discretionary bonuses or sales…