Senior Android Developer

Location: Poland (PL)

Experience Level: Senior

Description

We are looking for highly technical Senior Android Developer with deep ad-monetization expertise to build and optimize the ad-monetization stack directly inside our mobile applications. This is an Android-first engineering role: you'll write and own the Android (Kotlin/Java) code that integrates and optimizes mediation SDKs, ad placement, frequency, and bidding — backed by the backend services that drive real-time monetization decisions — to maximize revenue, fill rate, and eCPM on apps that reach millions of users.

Responsibilities:

• Design, develop, and optimize the core monetization infrastructure across multiple mobile applications.
• Improve ad waterfall and bidding performance to maximize eCPM, fill rate, ARPDAU, and total ad revenue.
• Integrate and optimize mediation platforms (AppLovin MAX, AdMob, LevelPlay, etc.).
• Build intelligent optimization systems for ad placement, frequency, segmentation, and pricing.
• Develop backend services and automation tools for real-time monetization decisions.
• Analyze monetization performance using large-scale data and implement data-driven improvements.
• Optimize SDK integrations, latency, memory usage, and overall ad performance.
• Work closely with Growth, Product, and Data teams to continuously increase LTV and user monetization.
• Research and implement new monetization technologies, bidding strategies, and demand sources.

What you'll own

• Increase overall monetization performance across millions of users.
• Maximize fill rate, eCPM, advertiser competition, and total revenue.
• Build the next generation of the monetization engine using automation and AI.
• Deliver measurable business impact through engineering excellence.

Requirements

Must-have skills:

• Android development (28%) — strong hands-on Android engineering in Kotlin/Java: Android SDK, app architecture, lifecycle, threading/concurrency, memory and performance optimization. This is the primary skill for the role.
• Ad-monetization domain (20%) — deep understanding of RTB, Header Bidding, Waterfalls, Fill Rate, eCPM/CPM optimization, ARPDAU, and advertiser demand.
• Ad mediation platforms + mobile advertising SDKs (17%) — hands-on integration and optimization of mediation SDKs (AppLovin MAX, AdMob, IronSource, LevelPlay).
• Software development (15%) — solid backend services, APIs, distributed systems, and performance optimization to power real-time monetization decisions.
• Analytical, data-driven optimization (12%) — analyze large-scale monetization data and implement data-driven improvements.
• High-scale consumer app experience (8%) — experience with high-scale consumer applications reaching millions of users.

Nice-to-have skills:

• iOS development (Swift) — a plus but not required; this is an Android-first role.
• Hands-on with AppLovin MAX, Google Ad Manager, AdMob, Unity Ads, or IronSource.
• Building internal optimization engines using AI or Machine Learning.
• Familiarity with attribution, user segmentation, A/B testing, and predictive monetization models.