This role is hands-on and research-oriented: you will implement and evaluate RL algorithms, instrument training pipelines, collaborate closely with data and platform engineers, and ensure the model operates correctly within the constraints of clinical eligibility rules and program-specific reward structures.

Key Responsibilities

Reinforcement Learning Model Development

• Design, implement, and evaluate RL algorithms suited to long-horizon, sparse-reward healthcare decisioning, including policy gradient methods (PPO, A3C), value-based approaches (DQN, Q-learning), and offline RL methods (CQL, Decision Transformer).

• Define and maintain the member state representation and action space, evolving both as new programs and data sources are onboarded.

• Apply the Bellman equation, reward shaping, and constraint mapping to encode clinical eligibility, suppression rules, and program-specific objectives directly into the learning objective.

• Manage exploration-exploitation tradeoffs appropriate for a production healthcare environment where poorly explored actions have real member impact.

Model Evaluation and Production Safety

• Build simulation and backtesting environments to evaluate policy quality before production promotion, using historical member journey data.

• Diagnose and remediate common RL failure modes: policy collapse, credit assignment errors across long member journeys, and distributional shift between training and serving populations.

• Define reward threshold criteria and automated evaluation gates within the nightly Databricks training workflow; block promotion of underperforming policies to MLflow production.

• Instrument training runs with MLflow tracking hyperparameters, reward curves, action distribution, and feature importance for every training cycle.

Training Pipeline Engineering

• Own the nightly Databricks training workflow: feature engineering from Gold Activity History and Gold Patient Profile, state vector normalization, distributed RL training via Ray RLlib, and batch scoring of all 8M eligible members.

• Collaborate with the Data Engineering team (Decisioning Team 2) to ensure training inputs are correctly joined, reward signals are accurately computed from disposition outcomes, and the feature pipeline is reproducible and auditable.

• Write production-quality PySpark feature engineering jobs; maintain data lineage through Databricks Unity Catalog.

• Manage model artifacts, versioning, and lifecycle in the MLflow Model Registry; ensure rollback capability is maintained at all times.

Multi-Agent and Constraint-Aware Decisioning

• Apply multi-agent RL concepts (MARL via PettingZoo) where member household or population-level coordination is required.

• Implement constraint mapping to enforce hard business rules — member caps, cooldown periods, clinical eligibility — as constraints within the RL objective rather than downstream filters.

• Collaborate with the Rules Engine team to ensure Drools eligibility guards and RL policy priorities are correctly aligned and do not conflict.

Collaboration and Governance

• Partner with Decisioning Team 1 (Decision Engine, Rules Engine) to ensure model outputs integrate cleanly with the real-time decisioning hot path and that scored recommendations cached in Redis are correctly structured and interpreted.

• Collaborate with platform architects to define feedback loop contracts: how disposition outcomes flow from Kafka back through Databricks Delta Live Tables into the next training cycle.

• Document model behavior, known limitations, and failure modes for clinical and compliance stakeholders; support explainability requirements for member-facing decisions.

• Utilize AI-assisted engineering tools for scaffolding, testing, and documentation; ensure all core model logic and reward design remain human-authored and subject to rigorous peer review.

Required Qualifications

• Bachelor's degree in computer science or related field

• 8+ years of software engineering experience building and operating large-scale production systems, with emphasis on data-intensive platforms, recommendation systems, or optimization engines serving millions of users.

• 3+ years of hands-on experience implementing reinforcement learning or deep learning systems in production policy gradient methods (PPO, A3C), value-based approaches (DQN, Q-learning), or offline RL algorithms (CQL, Decision Transformer).

• Deep familiarity with the Bellman equation, reward shaping, exploration-exploitation tradeoff, and constraint mapping in real-world RL systems.

• Demonstrated ability to diagnose RL-specific failure modes: policy collapse, credit assignment issues, and distributional shift across large populations.

• Proficiency in Python 3.x; experience with PyTorch or TensorFlow for policy network implementation.

• Experience with Ray RLlib for distributed RL training at scale.

• Experience with Databricks, PySpark, and Delta Lake for large-scale ML pipelines processing tens of millions of records.

• Experience with MLflow for experiment tracking, model registry, and artifact management.

• Track record of shipping ML systems that operate reliably under production load — not just research or prototype work.

Preferred Qualifications

• Experience with multi-agent RL frameworks (PettingZoo or equivalent).

• Familiarity with probabilistic modeling, Markov Decision Processes, and linear programming for constraint-aware action selection.

• Experience operating RL systems in regulated domains — healthcare, finance, or insurance — where member safety, auditability, and explainability are requirements.

• Experience with Gymnasium for simulation environment development and backtesting.

• Familiarity with Kafka-based feedback loops and how disposition signals feed RL retraining pipelines.

• OpenTelemetry instrumentation experience for ML training pipeline observability.

Additional Information

This role is not eligible for work visa sponsorship.

Work Style: Remote/Hybrid - Preferably Boston, MA. Occasional travel to Humana's offices for training or meetings may be required.

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

Very minimal travel might be required for training, meetings, and/or conferences

Interview Format

As part of our hiring process, we will be using on-demand technology provided by Hire Vue, a third-party vendor. This technology provides our team of recruiters and hiring managers with an enhanced method for decision-making through on-demand candidate assessments.

If you are selected to move forward from your application prescreen, you will receive correspondence inviting you to participate in an on-demand assessment with pre-determined questions. You should anticipate the assessment to take approximately 10-15 minutes.

Your on-demand assessment will be reviewed, and you will subsequently be informed if you will be moving forward to next round of interviews.

SSN Task via Workday

Should you be extended a formal employment offer you will receive a request to enter your SSN into our Workday system to scan for duplicate profiles.

Scheduled Weekly Hours

Pay Range

Description of Benefits