Senior Java Engineer

The position is open for a global, publicly traded AdTech market leader. The company's platforms handle over 1 trillion requests per day, operating within a highly optimized real-time cloud architecture across dozens of servers and processing terabytes of data daily.

The engineering team focuses on intense performance optimization, low-latency infrastructure, asynchronous data streaming, and cutting-edge GenAI research and development.

• Salary: upto $5,000 USD / month.
• Format: Full-time. Hybrid (Budva, Montenegro) or 100% Remote globally
• Contract Type: B2B Contract

Responsibilities

• Design, scale, and maintain real-time advertising bidding systems (DSPs, RTB Exchanges, and SSP platforms).
• Optimize backend services using Java (Spring Boot / WebFlux) and Go (Golang) to meet strict low-latency SLA/SLO targets.
• Build and manage data-intensive architectures utilizing high-load storage solutions (Aerospike, ClickHouse) and event-driven messaging (Apache Kafka).
• Participate in R&D initiatives involving GenAI, integrating Agentic AI frameworks (LangChain, LangGraph, N8N) for workflow automation and predictive analytics.
• Take full ownership of features end-to-end, contributing to the frontend layer (React / TypeScript) for internal tools and dashboards when required.

• 5+ years of commercial software development experience with Java as the primary language.
• Deep knowledge of the Spring ecosystem (Boot, Data, MVC, Security, Cloud) and strong practical experience with reactive/asynchronous programming (Spring WebFlux / Project Reactor).
• Solid understanding of distributed systems, concurrency, and performance tuning at the JVM level.
• Strong verbal English skills at B2 level or higher, with the ability to explain architectural decisions and collaborate directly with a global engineering team during voice calls.
• Location outside of the Russian Federation due to contractual and payment restrictions. Candidates from Belarus are eligible only if they possess an active legal entity/IP in Georgia or Europe for international payments.
• Commercial programming experience or strong familiarity with Go (Golang).
• Hands-on experience with high-load and Big Data tools including Apache Kafka, ClickHouse, and Aerospike.
• Real-world experience or deep interest in LLMs and AI orchestration tools such as LangChain, LangGraph, or N8N.
• Familiarity with frontend development using ReactJS and TypeScript.

• Opportunity to work on production infrastructure handling 1 trillion + daily requests.
• Work within a team of senior engineers with direct impact on the platform's architecture.
• Choice between a fully remote schedule or a hybrid format from the office in Budva, Montenegro.
• Stable monthly payments in USD via international B2B contracts.