Senior Java Engineer — Backend Services

Who we are:

Adaptiq is a technology hub focused on building, scaling, and supporting R&D teams for high-growth product companies across a broad range of industries.
 

About the Product:

Our client is a leading online gaming operator developing a new transactional platform for user account management. The platform is being built from scratch and will operate in a highly regulated, high-volume environment, supporting millions of concurrent users.

It will process real-time financial transactions and must provide high availability, sub-second response times, strong data integrity, security, and complete auditability. A major technical challenge is ensuring stable performance and reliability during peak events and significant traffic spikes.

The team is looking for strong engineering expertise to help architect and develop a scalable, high-performance, and resilient backend platform while meeting strict security, regulatory, and compliance standards.
 

About the Role:

As a Senior Java Engineer, you will build and design the core backend services of the PAM platform from the ground up. You will take end-to-end ownership of features, covering technical design, implementation, automated testing, production monitoring, and release.

You will collaborate closely with Principal Engineers on architecture and key technical decisions, contribute to RFCs, and deliver production-ready solutions. The role offers a high degree of autonomy and direct influence on the platform architecture, together with responsibility for reliability, performance, and correctness within a critical financial system.
 

Key Responsibilities:

• Design and develop backend services using Java 17+ and Spring Boot or a similar framework, covering wallet transactions, ledger entries, payment orchestration, bonus mechanics, and account state management.
• Build REST APIs and event-driven integrations with Kafka or similar technologies for player-facing applications, operational tools, and external partners.
• Maintain system correctness and reliability through idempotent operations, well-defined transaction boundaries, explicit failure handling, and comprehensive unit, integration, and contract testing.
• Incorporate regulatory requirements directly into the platform, including KYC/AML checks, responsible gaming controls, and audit trails.
• Ensure production readiness through metrics, structured logging, distributed tracing, alerting, and participation in on-call rotations.
• Participate in technical design discussions and RFCs, conduct code reviews, and support and mentor other engineers.
• Integrate AI-assisted development tools into the daily engineering workflow while following established platform standards for prompts and context.
• Support the live migration from the existing third-party platform, including parity testing, data validation, and cutover coordination.
   

Required Competence and Skills:

• 5+ years of backend engineering experience with strong hands-on expertise in Java 17+ and a modern framework such as Spring Boot.
• Proven experience designing, building, and operating high-integrity transactional systems in areas such as payments, wallets, billing, banking, e-commerce, or gaming.
• Strong knowledge of relational databases such as PostgreSQL, including schema design, ACID transactions, locking, and query/performance optimization.
• Experience working with event-driven architectures and messaging technologies such as Kafka, RabbitMQ, or similar, including idempotency and retry mechanisms.
• Strong automated testing practices, including unit, integration, and contract testing as part of the regular development lifecycle.
• Practical production experience with containers, CI/CD pipelines, monitoring and telemetry, as well as troubleshooting production incidents.
• Solid knowledge of multi-threading, system architecture, and fault-tolerant design patterns.
• Good written and spoken English and experience collaborating effectively across distributed, multi-time-zone teams.
   

Nice to Have:

• Experience in iGaming, sports betting, fintech, or another regulated domain with high transaction volumes.
• Hands-on exposure to Kubernetes and AWS technologies, including VPC, IAM, EKS, and auto-scaling.
• Experience building systems with compliance requirements such as KYC/AML, responsible gaming, and auditability.
• Practical experience using AI coding assistants and agentic development workflows.
• Polish and/or Spanish language skills.
   

Why Us:

We provide 20 days of paid vacation per calendar year, in addition to the official national holidays of the country where you are based.

We offer full accounting and legal support across all countries where we operate.

We follow a fully remote work model and provide a powerful workstation, as well as access to a co-working space whenever needed.