Senior Backend Engineer

Senior Backend Engineer (Kotlin/Java)This position is posted by Jobgether on behalf of a partner company. We are currently looking for a Senior Backend Engineer (Kotlin/Java) in Poland.This role offers the opportunity to design and build highly scalable backend systems used in complex, distributed environments. As a Senior Backend Engineer, you will work on high-throughput, event-driven architectures and contribute to mission-critical services that integrate with third-party platforms at scale. You will collaborate with experienced engineers in an Agile and DevOps-driven environment, where code quality, reliability, and observability are top priorities. The position is fully remote and provides exposure to challenging international projects. Your work will directly impact system performance, resilience, and long-term technical scalability. This role is ideal for engineers who enjoy solving complex backend problems and taking ownership of production-grade systems.Accountabilities:Design, develop, and maintain scalable backend services using Kotlin and Java in high-load environments.Build and evolve event-driven and message-based systems using technologies such as Kafka or equivalent platforms.Implement distributed system patterns including idempotency, sagas, retries, and eventual consistency.Develop and optimize integrations with high-volume third-party APIs, ensuring resilience, throttling, and backpressure handling.Provision, configure, and optimize cloud infrastructure using Terraform and managed cloud services.Optimize write-heavy data stores such as PostgreSQL or Cassandra, including indexing and connection pooling strategies.Ensure high code quality through strong testing practices, including unit, integration, and performance testing.Collaborate within Agile teams, contributing to continuous delivery, observability, and DevOps best practices.Requirements:7+ years of backend software engineering experience building production-grade, large-scale systems.6+ years of hands-on experience with Kotlin and Java in enterprise or high-throughput environments.Strong expertise in concurrency and thread-safe programming, including coroutines and/or virtual threads.Proven experience with distributed systems and event-driven architectures.Hands-on experience with cloud infrastructure, preferably AWS, and infrastructure-as-code tools such as Terraform.Experience working with relational and NoSQL databases, including PostgreSQL and Cassandra.Strong understanding of secure integrations, including OAuth2, mTLS, and token management.Solid testing mindset across microservices and distributed failure scenarios.Excellent English communication skills and the ability to work effectively in remote, international teams.Bachelors degree in Computer Science or equivalent practical experience.Benefits:Fully remote, long-term position with flexible working hours.Compensation in USD with stable, long-term engagement.Paid time off and paid national holidays based on country of residence.Unlimited access to professional learning resources, including technical and English training platforms.Benefits linked to cloud technology partnerships.Company-provided laptop for remote work.Clear career path development and growth opportunities.Exposure to challenging projects with international clients.Why Apply Through Jobgether?We use an AI-powered matching process to ensure your application is reviewed quickly, objectively, and fairly against the role's core requirements. Our system identifies the top-fitting candidates, and this shortlist is then shared directly with the hiring company. The final decision and next steps (interviews, assessments) are managed by their internal team.We appreciate your interest and wish you the best Why Apply Through Jobgether? Data Privacy Notice: By submitting your application, you acknowledge that Jobgether will process your personal data to evaluate your candidacy and share relevant information with the hiring employer. This processing is based on legitimate interest and pre-contractual measures under applicable data protection laws (including GDPR). You may exercise your rights (access, rectification, erasure, objection) at any time.#LI-CL1PI62f367c487ec-30511-39477440