Senior Software Engineer

We are seeking an accomplished Senior Software Engineer to design, implement, and operate mission-critical stateful services that form the backbone of real-time, automated decisioning and personalization platforms.

These systems are responsible for maintaining authoritative state, orchestrating lifecycle transitions, and ensuring reliable downstream effects,often in high-concurrency, low-latency environments.

This position is ideal for engineers with a strong grasp of state machines, idempotency, distributed systems, and “exactly-once” execution semantics.

Key Responsibilities

• State Machine Architecture & Implementation
• Design, build, and maintain explicit state machines governing lifecycle transitions, validation of permissible transitions, and time-based and event-driven changes.
• Ensure state machines are clearly modeled, deterministic, reproducible, auditable, and easily understood and testable.

• Transactional State Memory & Exactly-Once Processing
• Architect and manage transactional state stores serving as the single source of truth.
• Support safe, high-concurrency read/write operations and uphold system invariants across partial failures and recovery scenarios.
• Implement robust idempotency controls so requests can be safely retried, commands execute at most once, and duplicate events do not compromise state integrity.

• Reliable Side Effects via Outbox Pattern
• Employ the outbox pattern to guarantee atomicity of state updates and event publication.
• Prevent loss or duplication of side effects and maintain clear separation between state mutation and downstream event delivery.

• Distributed Systems & Concurrency Management
• Design for correctness under concurrent updates, network partitions, partial failures, and service redeployments.
• Apply expertise in idempotency keys, optimistic and pessimistic locking strategies, and event ordering and causality.

• AI-Assisted & Agentic Engineering Practices
• Leverage AI-powered and agentic tools to automatically generate and validate state transition tests, probe edge cases and concurrency challenges, assist in code reviews, refactoring, and documentation, and accelerate debugging, incident analysis, and root cause discovery.

• Observability, Auditability & Trust
• Engineer services with robust observability through structured logging, metrics, and alerting, and distributed tracing.
• Ensure all state transitions and emitted events are fully traceable and reproducible, and auditable for compliance and investigative needs.

• Collaboration & Technical Leadership
• Partner with platform, data, and quality engineering teams to assure end-to-end reliability.
• Participate in architecture and design reviews to elevate system quality standards.
• Mentor and guide engineers on best practices for safe, reliable, and maintainable distributed systems.

Required Qualifications

• Bachelor's degree in computer science or related field
• 6+ years of experience in backend or platform engineering
• Demonstrated hands-on expertise with state machine modeling and lifecycle management, transactional state stores, and idempotent API and workflow design
• In-depth understanding of exactly-once or effectively once processing, and failure modes in distributed environments
• Proficiency in one or more contemporary languages (e.g., Java, Kotlin, Go, Python)
• Experience with AI-assisted development tools for productivity and code quality

Preferred Qualifications

• Experience with outbox, transactional messaging, or event sourcing patterns
• Familiarity with low-latency, high-throughput architectures
• Operational experience in systems requiring strict auditability and correctness
• Background in regulated or mission-critical domains

Success Indicators

• State transitions are precise, deterministic, and resilient to retries.
• Side effects reliably occur exactly once, even during failures or replays.
• Systems recover gracefully from crashes and redeployments.
• AI-driven tooling decreases defect rates and expedites debugging.
• The state layer is trusted as the definitive source of truth across engineering teams.

Why This Role is Critical

In contemporary automated platforms, correctness and reliability hinge on the integrity of state, not just requests. This role ensures that every state transition and side effect is executed once,and only once,providing a solid foundation for trust, reliability, compliance, and scalability throughout the system.

Work Style: Remote/Hybrid.

Work Hours: Typical business hours are Monday-Friday, 8 hours/day, 5 days/week-- some flexibility might be possible, depending on business needs.

Pay Range: $106,900 - $147,000 per year

Description of Benefits

Humana, Inc. and its affiliated subsidiaries (collectively, “Humana”) offers competitive benefits that support whole-person well-being. Associate benefits are designed to encourage personal wellness and smart healthcare decisions for you and your family while also knowing your life extends outside of work. Among our benefits, Humana provides medical, dental and vision benefits, 401(k) retirement savings plan, time off (including paid time off, company and personal holidays, paid parental and caregiver leave), short-term and long-term disability, life insurance and many other opportunities.