Research Scientist, LLM Evaluation & Post-Training

About Centific
Centific is a frontier AI data foundry that curates diverse, high-quality data, using our purpose-built technology platforms to empower the Magnificent Seven and our enterprise clients with safe, scalable AI deployment. Our team includes more than 150 PhDs and data scientists, along with more than 4,000 AI practitioners and engineers. We harness the power of an integrated solution ecosystem—comprising industry-leading partnerships and 1.8 million vertical domain experts in more than 230 markets—to create contextual, multilingual, pre-trained datasets; fine-tuned, industry-specific LLMs; and RAG pipelines supported by vector databases. Our zero-distance innovation™ solutions for GenAI can reduce GenAI costs by up to 80% and bring solutions to market 50% faster.
Our mission is to bridge the gap between AI creators and industry leaders by bringing best practices in GenAI to unicorn innovators and enterprise customers. We aim to help these organizations unlock significant business value by deploying GenAI at scale, helping to ensure they stay at the forefront of technological advancement and maintain a competitive edge in their respective markets.
About Job
Role: Senior Applied Reinforcement Learning Engineer
Location: Palo Alto, CA or Seattle, WA (Hybrid/Remote)
About the Team
Centific AI Research advances foundational AI models and applications through reinforcement learning, alignment, and human-centered intelligence. Our mission is to transform data, signals, and human insight into next-generation intelligent systems that redefine enterprise intelligence.
We're building a governed RL environment platform that enables enterprises to safely iterate and improve AI agent workflows through simulation-based learning, bridging human-labeled signal creation with automated RL training for high-stakes operations.
Role Overview
As an Applied RL Engineer, you will design and build RL environments that simulate complex enterprise workflows and train intelligent agents within them. You'll work at the intersection of RL research and production systems, translating customer requirements into bespoke simulation environments and post-training pipelines that deliver measurable improvements to AI agent performance.
This role requires deep expertise in both classical RL methodologies and modern LLM-based agent architectures. You'll shape our product direction and help make RL accessible to enterprise customers who need safe, compliant ways to improve their AI systems.
Core RL Competencies

Foundational RL

MDPs & value methods: State/action spaces, Q-learning, DQN, Double DQN, Dueling DQN

Policy gradient methods: REINFORCE, Actor-Critic, A2C/A3C, variance reduction

Advanced optimization: PPO, TRPO, SAC, trust regions, entropy regularization

TD learning: TD(0), TD(λ), eligibility traces, bootstrapping methods

LLM Alignment & Post-Training

RLHF pipelines: Reward model training, preference learning, human feedback integration

Direct optimization: DPO, IPO, KTO, offline preference optimization

Group-based methods: GRPO, RLOO, sample-efficient policy improvement

Reward modeling: Bradley-Terry models, reward hacking mitigation, KL constraints

Environment Design

Gymnasium/OpenAI Gym: Custom environments, observation/action spaces, wrapper patterns

Reward engineering: Sparse vs. dense rewards, potential-based shaping, intrinsic motivation

Verifier design: Programmatic reward functions, outcome verification, ground-truth evaluation

Simulation: Sim-to-real transfer, domain randomization, multi-agent dynamics

Advanced Techniques

Offline RL: CQL, BCQ, IQL for learning from fixed datasets without environment interaction

Model-based RL: World models, Dreamer, MuZero, learned dynamics

Hierarchical RL: Options framework, goal-conditioned policies, temporal abstraction

Imitation & exploration: Behavioral cloning, GAIL, curiosity-driven exploration, UCB

Key Responsibilities

Design and build custom RL environments (digital twins) simulating enterprise workflows: document processing, compliance, onboarding, support automation

Post-train LLM-based agents on domain-specific tasks using PPO, GRPO, DPO, and RLHF

Build end-to-end pipelines converting human-labeled traces into RL training data

Architect multi-step reasoning agents with tool-calling and closed learning loops

Design reward functions, verifiers, and validation frameworks for pre-deployment testing

Translate cutting-edge RL research into production systems; contribute to publications

Required Qualifications

Deep RL expertise: 3+ years hands-on experience with environment design, reward engineering, policy optimization

LLM post-training: Experience fine-tuning LLMs using RLHF, DPO, PPO, or similar

Production skills: Software engineering beyond research with scalable pipelines and training infrastructure

Agentic AI: Experience with LLM-based agents, tool use, multi-step reasoning

Technical stack: Strong Python; Gymnasium, RLlib, Stable Baselines; PyTorch/JAX/TensorFlow

Education: MS/PhD in CS, ML, or related field (or equivalent experience)

Preferred Qualifications

Publications at NeurIPS, ICML, ICLR, ACL, or similar venues

Enterprise workflow experience in healthcare, finance, logistics, or compliance

Open-source contributions to CleanRL, TRL, veRL, or agent frameworks

Experience with world models, synthetic data generation, and simulation

Distributed training and large-scale RL experimentation

Why Join Centific

Lead the frontier: Shape a new discipline at the intersection of RL, simulation, and enterprise AI

Ship your science: See your research power real systems across healthcare, finance, and safety

Collaborate with leaders: Work alongside NVIDIA, Microsoft, and the global AI community

Build what matters: Create governed, compliant AI systems enterprises can trust.

Salary: $150K - $300K Annually

Centific is an equal-opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, national origin, ancestry, citizenship status, age, mental or physical disability, medical condition, sex (including pregnancy), gender identity or expression, sexual orientation, marital status, familial status, veteran status, or any other characteristic protected by applicable law. We consider qualified applicants regardless of criminal histories, consistent with legal requirements.
Originally posted on Himalayas