Senior Software Engineer - Next Best Action

Senior Software Engineer

Become a part of our caring community and help us put health first. 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. You will also employ advanced AI-assisted and agentic engineering tools to drive correctness, velocity, resilience, and scalability.

Key Responsibilities

State Machine Architecture & Implementation

• Design, build, and maintain explicit state machines governing:
• Lifecycle transitions (e.g., open → in progress → completed → suppressed)
• Validation of permissible transitions
• Time-based and event-driven changes
• Ensure state machines are:
• Clearly modeled and not hidden in code logic
• Deterministic, reproducible, and auditable
• Easily understood and testable
• Robust against illegal or duplicate transitions through comprehensive validation

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
• Uphold system invariants across partial failures and recovery scenarios
• Implement robust idempotency controls so:
• Requests can be safely retried
• Commands execute at most once
• Duplicate events do not compromise state integrity
• Develop APIs and workflows resilient to retries, restarts, and replay events

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
• Maintain clear separation between state mutation and downstream event delivery
• Facilitate replay, backfill, and recovery operations without breaching state guarantees
• Integrate seamlessly with messaging and streaming platforms, ensuring fault tolerance

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
• Event ordering and causality
• Balance rigorous correctness with performance and latency requirements

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
• Accelerate debugging, incident analysis, and root cause discovery
• Use AI responsibly to enhance productivity while maintaining clarity and system integrity

Observability, Auditability & Trust

• Engineer services with robust observability through:
• Structured logging, metrics, and alerting
• Distributed tracing
• Ensure all state transitions and emitted events are:
• Fully traceable and reproducible
• 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

Use your skills to make an impact

Required Qualifications

6+ years of experience in backend or platform engineering

• Demonstrated hands-on expertise with:
• State machine modeling and lifecycle management
• Transactional state stores
• Idempotent API and workflow design
• In-depth understanding of:
• Exactly-once or effectively-once processing
• 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.

Additional Information

Qualified candidates are required to currently live in, or be willing to move to, a commutable distance for a hybrid (~3 days in-office) work arrangement. Location options are currently:

• Washington, D.C. metropolitan area
• Louisville, KY metropolitan area
• Denver, CO metropolitan area
• Dallas, TX metropolitan area
• Ft. Lauderdale, FL metropolitan area

SSN Alert Statement: Humana values personal identity protection. Please be aware that applicants may be asked to provide their Social Security Number, if it is not already on file. When required, an email will be sent from Humana@myworkday.com with instructions on how to add the information into your official application on Humana's secure website.

Travel: While this is a remote position, occasional travel to Humana's offices for training or meetings may be required.

Scheduled Weekly Hours: 40

Pay Range: The compensation range below reflects a good faith estimate of starting base pay for full time (40 hours per week) employment at the time of posting. The pay range may be higher or lower based on geographic location and individual pay will vary based on demonstrated job related skills, knowledge, experience, education, certifications, etc. $106,900 - $147,000 per year. This job is eligible for a bonus incentive plan. This incentive opportunity is based upon company and/or individual performance.

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, volunteer time off, paid parental and caregiver leave), short-term and long-term disability, life insurance and many other opportunities.

Application Deadline: 04-02-2026

About us: Humana Inc. (NYSE: HUM) is committed to putting health first – for our teammates, our customers and our company. Through our Humana insurance services and CenterWell healthcare services, we make it easier for the millions of