Senior Java Developer

Ntiative Zobacz wszystkie oferty

Warszawa

Wygasa 15 paź 2026

3 dni temu

W skrócie

Senior Java Developer needed for Ntiative in Warsaw. Develop features for a complex billing/subscription system using Java 21, Kotlin, Spring Boot. Requires 5+ years Java experience, distributed systems, SQL, and automated testing. Experience with Kafka, Redis, and MySQL is crucial.

Słowa kluczowe

java kotlin spring boot kafka redis sql mysql hibernate junit mockito

Skrót przygotowany przez AI na podstawie treści ogłoszenia.

About Company:

Piano’s Digital Revenue Optimization solution helps digital services grow revenue by betterunderstanding and influencing their customers’ behavior. Piano unifies analytics, segmentation, andcommercial personalization in one AI-driven application, enabling sites and apps to efficientlymaximize the value of every user visit. Headquartered in Amsterdam with offices in the Americas, Europe, and Asia-Pacific, Piano serves a global client base including the BBC, Deutsche Telekom, Nikkei, AXA and the Wall Street Journal. For more information, visit piano.io.

About the project:

You’ll join a team working on a high-complexity system in the billing & subscription managementdomain. The platform uses a hybrid architecture (monolith + selected microservices) and a hybridtechnology stack, requiring strong engineering judgment around consistency, correctness, reliability, and scalability. Critical domain: billing cycles, and subscription lifecycles across multiple payment providers.

Precision and data integrity are non-negotiable. Distributed architecture: event-driven patterns (Kafka), Outbox patterns, and distributedcoordination (Redis/Redisson distributed locks). Hybrid ecosystem: mix of Spring Boot + Jersey + Guice, split between Java 21 and Kotlin2.0. Scale & resilience: resilience patterns (Resilience4j), observability (Datadog/OpenTelemetry),and scheduling (Quartz).

What you’ll do: Collaborate with technical leaders and architects to efficiently deliver new functionalities in acomplex domain. Plan, design, and implement new features with a strong focus on reliability, consistency, andmaintainability. Solve production problems before they affect customer experience (root-cause analysis, mitigation, and long-term fixes). Contribute to engineering: testing strategy, performance, observability, and operationalreadiness.

Expected qualifications: 5+ years of experience as a Java Developer (enterprise systems preferred). Strong proficiency in Java (up to v21) and plus would be a solid experience with Kotlin. Experience with Spring Boot (2.7+) / Spring Framework. Good level of understanding of SQL (MySQL 8) and ORM (Hibernate), including: transactionisolation and locking strategies; performance tuning Hands-on distributed systems experience: Kafka (event design, consumer reliability, exactly/at-least-once thinking); Redis / Redisson (distributed locks, concurrency handling);designing for eventual consistency, idempotency, and failure scenarios Strong automated testing culture: JUnit 5, Mockito, Testcontainers Polish, English (B2)

Nice to have: Cloud/infra: Basic understanding of AWS, Docker/Docker Compose. Observability: Datadog, OpenTelemetry, distributed tracing/metrics-first mindset. Payments: experience integrating Stripe Computer Science degree Selenium experience

Current Tech stack: Languages: Java 21, Kotlin2.0 Frameworks: Spring Boot, Guice, Jersey (JAX-RS) Data: MySQL 8.0, Redis (Redisson), Hibernate 5.6, DynamoDB Messaging: Apache Kafka Resilience / Scheduling: Resilience4j Observability: Datadog, OpenTelemetry Build: Gradle (KotlinDSL) Infrastructure: Docker, AWS, Kubernetes