Senior Kotlin/Spring Boot Engineer

Company: EPAM Systems

EPAM is a leading global provider of digital platform engineering and development services. We are committed to having a positive impact on our customers, our employees, and our communities. We embrace a dynamic and inclusive culture. Here you will collaborate with multi-national teams, contribute to a myriad of innovative projects that deliver the most creative and cutting-edge solutions, and have an opportunity to continuously learn and grow. No matter where you are located, you will join a dedicated, creative, and diverse community that will help you discover your fullest potential.
We are hiring a Senior Kotlin/Spring Boot Engineer to help own the execution backbone of a no-code workflow platform. This is not a simple CRUD service. The Orchestrator runtime is a multi-module system that receives workflow execution requests, persists durable state with Temporal, coordinates graph execution, integrates HTTP, agent, LLM, and human-review nodes, and safely executes increasingly AI-generated workflow graphs. You'll join the squad responsible for the runtime layer that everything else depends on.
Responsibilities
* Design and harden the Kotlin/Spring Boot runtime that executes workflow graphs reliably in production
* Implement and improve Temporal.io workflows, activities, signals, queries, retries, and recovery paths
* Strengthen contract-first APIs and shared contracts
* Own failure-mode thinking across distributed execution retries, idempotency, partial failure, replay safety, pause/resume, and graceful degradation
* Work across node types, including HTTP, agentic tool-calling, LLM, and human-in-the-loop review nodes
* Improve integration coverage using Testcontainers and layered Docker Compose profiles
* Collaborate closely with Composer and AI/KB teams on execution semantics and runtime behavior
* Write clear operational documentation and runbooks for a reliability-critical service
Requirements
* 3+ years of backend development experience in distributed systems or platform services, with strong expertise in Java and Spring Boot
* Hands-on production experience with Temporal.io
* Understanding of workflow durability, retries, idempotency, and recovery design
* Background in multi-module Gradle codebases and contract-first API design
* Proficiency in JPA/Hibernate and PostgreSQL
* Skills in integration testing with Docker Compose and Testcontainers
* Capability to debug multi-service systems with mixed Kotlin and Python components
* Familiarity with observability tools such as Micrometer
* Experience with contract-first development
* Strong English communication skills (B2 level or higher)
Nice to have
* Strong production experience with Kotlin backend development
* Expertise in DAG/workflow/orchestration engines
* Background in AI/LLM/agent runtimes or other non-deterministic execution systems
* Familiarity with FastAPI-based workers and cross-language integration
* Knowledge of auth/token provider abstractions, OAuth2/JWT, and cached token acquisition
* Experience writing operational docs, runbooks, and reliability guidance
We offer
* International projects with top brands
* Work with global teams of highly skilled, diverse peers
* Healthcare benefits
* Employee financial programs
* Paid time off and sick leave
* Upskilling, reskilling and certification courses
* Unlimited access to the LinkedIn Learning library and 22,000+ courses
* Global career opportunities
* Volunteer and community involvement opportunities
* EPAM Employee Groups
* Award-winning culture recognized by Glassdoor, Newsweek and LinkedIn

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