Senior Backend Engineer (Core Team)

Location: European Union; Ukraine Workplace: Remote About the Role We’re looking for a Senior Backend Developer who thrives in a deeply hands-on environment and enjoys being close to the code on a daily basis. This role is heavily focused on building, optimising, and scaling backend services in a high-load system where performance and reliability are critical. You’ll be working on complex, real-time challenges at the core of our platform - improving latency, ensuring high availability, and making systems more efficient at scale. This is not a coordination-heavy role; it’s for someone who enjoys writing production code, solving tough engineering problems, and seeing the direct impact of their work. If you’re product-driven, take ownership, and prefer a “build first, improve fast” approach while working on systems where every millisecond matters - this role will feel like home. Key Responsibilities - Work as part of a cross-functional team owning a core product within the platform - Design, build, and deliver new backend features end-to-end in a distributed environment - Write high-quality, production-level code daily, contributing directly to a high-load, scalable system - Take ownership of services handling financial transactions at scale, with a strong focus on reliability and accuracy - Proactively suggest and implement improvements in architecture, processes, and development practices - Participate in code and architectural reviews to maintain high engineering standards - Solve complex business and technical challenges with pragmatic, efficient solutions - Participating in on-call rotations within the squad to ensure the reliability and availability of our systems - Play an active role in ongoing tech transformation initiatives across the platform - Collaborate closely with engineers, product, and other stakeholders to deliver impactful solutions used by millions globally Requirements - Solid experience with Node.js/TypeScript is ideal, but we also welcome experts in other OOP languages such as Java, Python, C++, C#, or Go - Strong understanding of asynchronous programming techniques - Deep production experience with Kafka: confident reasoning about consumer-group rebalances and their impact on in-flight processing, offset-commit strategies under retries and duplicate delivery, and the limits of "exactly-once" semantics - Experience designing idempotent, retry-safe handlers for at-least-once pipelines: transactional outbox, idempotency keys, and deduplication - Experience building services with gRPC or similar RPC frameworks - Strong knowledge of relational databases such as MySQL or PostgreSQL, plus production experience with at least one NoSQL technology at scale, such as DynamoDB, MongoDB, or Redis - Hands-on experience running services on Kubernetes and AWS/GCP: deployment, autoscaling, resource limits, and production debugging - Production operations experience: on-call ownership of a high-load system, including incident response, impact assessment, root-cause analysis, and post-incident improvements Nice to Have - Experience with ClickHouse or other columnar/analytical databases - Experience with multi-region / failover architectures: data replication, regional isolation, and graceful degradation - Practical use of AI coding agents such as Cursor or Claude Code as part of daily development: effective prompting, reviewing, and validating AI-generated code - Understanding of application security and industry best practices - Gambling domain experience What We Offer - Competitive Salary - Quarterly Bonuses - Unlimited Paid Time Off - Unlimited Paid Sick Leave - Remote & Flexible Working - Private Medical Insurance - Financial Support for Life Events - Professional Development Budget - International Exposure - Regular Company Events *Benefits may vary depending on location and contractual agreement Recruitment process 1. HR interview (30-45mins) 2. Interview with a Hiring Manager (45mins) 3. Technical interview with live coding (90mins) 4. Final Interview with C-level (60 mins) By submitting your application, you acknowledge that your personal data will be processed in accordance with our Privacy Policy https://playson.com/privacy.