Senior Kotlin/ Spring Boot Engineer

Job Title: Senior Kotlin/Spring Boot Engineer Location: Salt Lake City, UT or Phoenix, AZ or Sunrise, FL Worksite: Onsite About WCT WCT is a global talent solutions partner committed to delivering high-impact technology and engineering talent to some of the world’s most innovative companies. As a WCT employee, you’ll be part of a dynamic, growth-oriented culture that values collaboration, continuous learning, and excellence in execution. Job Summary • We’re hiring a senior Kotlin/Spring Boot contractor 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 Test containers 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. Qualifications: • Strong production Kotlin backend experience. • Strong Spring Boot experience in distributed systems or platform services. • Hands-on Temporal experience in production. • Strong understanding of workflow durability, retries, idempotency, and recovery design. • Experience with multi-module Gradle codebases and contract-first API design. • Experience with JPA/Hibernate and PostgreSQL. • Experience with Docker Compose/Test containers integration testing. • Comfort debugging multi-service systems with mixed Kotlin and Python components. • Experience with observability tools like micrometer • Experience with contract first development Strong Pluses: • Experience with DAG/workflow/orchestration engines. • Experience with AI/LLM/agent runtimes or other non-deterministic execution systems. • Familiarity with FastAPI-based workers and cross-language integration. • Experience with auth/token provider abstractions, OAuth2/JWT, or cached token acquisition. • Experience writing operational docs, runbooks, and reliability guidance. Compensation / Salary Range: The typical pay range for this role is: USD $110,000/Yearly - $125,000/Yearly. Factors that may affect pay within or outside of this range may include but not limited to geography/market, skills, education, experience, and other qualifications of the successful candidate. Benefits: Medical, dental, Vision, Life, PTO, Holidays, 401(k) benefits and ancillaries may be available for eligible WCT employees and may vary depending on the nature of your employment. WCT will accept applications and processes offers for these roles until the role is filled. Equal Employment Opportunity Declaration: WCT is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to age, ancestry, color, family or medical care leave, gender identity or expression, genetic information, marital status, medical condition, national origin, physical or mental disability, political affiliation, protected veteran status, race, religion, sex (including pregnancy), sexual orientation, or any other characteristic protected by applicable laws, regulations and ordinances.