Jobs Java

About The Project
We are building a large-scale automated advertising platform that powers the buying and selling of digital ads globally. The solution is used by leading publishers and applications to connect with brands and deliver ads to a massive audience worldwide.

The platform operates as a high-load, distributed system that supports multiple ad formats (including display, video, and digital out-of-home) across various devices. It focuses on real-time transactions, scalability, and efficient data processing to ensure seamless ad delivery and optimization.

Job Description

- Experience building and operating large-scale, high-throughput, enterprise apps
- 5+ years coding experience in server-side Java
- Excellent Java Core knowledge (Java 8 or higher, Collections, Exceptions, Concurrency)
- Experience with RDBMS (MySQL, PostgreSQL), native SQL, ORMs (Hibernate)
- Experience with automated testing frameworks (TDD, Mocking, Unit/Functional/Integration)
- Handy use of cloud services (AWS)
- Understanding of VCS (Git)
- Experience working in a Linux environment.
- Fluent English verbal and written communication skills
- Shifted working hours 1pm till 9pm EEST time zone

Nice to have experience with:
- Familiar with Scala, Spark
- Commercial experience with Spring Framework (Boot, Core, MVC, Data)
- Experience with Redis, Aerospike, RabbitMQ, Kafka, Camel
 

Job Responsibilities

- Write production-ready code and unit tests that meet both system and business requirements.
- Respond to feature requests, bug reports, performance issues, and ad-hoc questions.
- Work collaboratively with multiple teams to deliver quality software.
- Comfortable in multi-tasking and fast-pacing dev process.
- Support operation of services in production.

About the Role

We're looking for a Senior Java Engineer to lead the integration and enhancement of a recently acquired Payment Hub into our existing payments platform — ~232 PSP integrations, a cashier tier, and a set of core services running on EKS (AWS eu-central-1, ARM64) with GCP as a secondary region. You'll architect and build high-throughput backend services on modern Java and Spring Boot 3.x, onboard and mentor mid- and junior-level engineers, drive engineering standards, and partner with DevOps and Architects to deliver scalable, fault-tolerant solutions under real payment SLAs.

What We're Looking For

• 5+ years of backend Java experience; we run mostly Java 23 with newer services on Java 25, so fluency in modern Java (17+) is required.
• Production experience with Spring Boot 3.x, Spring Cloud, and the wider Spring ecosystem (Security, Data, OpenFeign, Actuator).
• Hands-on Apache Camel for EAI/integration — route design, DSL, and operating Camel under load (this is the integration backbone for our PSP tier).
• Experience with reactive Java — Spring WebFlux + Project Reactor + R2DBC — on latency-sensitive paths.
• Strong PostgreSQL skills with JPA/Hibernate (and ideally R2DBC), schema migrations via Liquibase.
• Kafka at scale — consumer-group design, delivery semantics, partition and rebalance tuning (AWS MSK or equivalent).
• Redis for caching, idempotency keys, and distributed locks (ShedLock or similar).
• Microservices, REST, OpenAPI-driven contracts, Maven build pipeline.
• Keycloak / OAuth2 / OIDC; secret management with Vault, External Secrets, or AWS Secrets Manager.
• Production AWS experience: EKS, MSK, RDS, ElastiCache, S3, CloudWatch, IAM/IRSA.
• Working knowledge of Docker, Kubernetes, Helm, and CI/CD (GitLab CI ideally).
• Solid grasp of high-load, fault-tolerant system design — circuit breaking, retries, back-pressure, p99 latency reasoning, capacity planning.
• Understanding of payment and financial systems.
• Strong communication, mentoring, and technical leadership skills.

Nice to Have

• Drools / DRL / decision tables (KIE Server experience a bonus) — used for routing, fraud/AML, and merchant-specific rules.
• OpenSearch for search and audit trails.
• Service mesh (Istio) and progressive delivery (Flagger / canary releases).
• Observability stack: Micrometer, Prometheus / VictoriaMetrics, Grafana, Datadog, OpenTelemetry.
• Infrastructure as Code with Terraform / Terragrunt.
• GitOps with Flux CD v2 and Helm.
• ARM64 / Graviton workloads, Karpenter-based autoscaling.
• AWS networking (VPC, Route 53, ELB) and security best practices.

What You'll Do

• Lead the design, development, and maintenance of Java microservices across the payments platform.
• Integrate and extend the new Payment Hub into our existing ecosystem.
• Drive code review, architectural decisions, and continuous improvement.
• Onboard and mentor junior and mid-level engineers — pair on real work, give thorough reviews, and help them level up.
• Champion best engineering practices: Testcontainers-first testing, observability, performance, secure coding, clean architecture.
• Run and present internal tech talks and share learnings across the team.
• Collaborate closely with DevOps on CI/CD, containerization, and infrastructure provisioning.
• Participate in on-call rotation for the services you own.

We Offer

• Fully remote work with a flexible schedule
• Paid sick leave and vacation
• Thoughtful gifts for holidays and personal milestones
• All equipment you need to do your job well
• Internal events: open discussions, product meetups, and soft-skills training
• Flat structure, no micromanagement, fast decision-making