Senior AI Engineer
About the Position
Alice's RL Environments team builds adversarial environments that the world's leading AI labs use to test and train their most capable agents. Each environment is a working replica of a real system with an attack planted inside it. A verifier decides whether the agent held up.
The environments run on AgenticVerse, our platform for building and running RL environments at scale. A large and fast-growing community of researchers works on it every day.
We're looking for a Senior AI Engineer to own those environments and the evaluation that decides which tasks are good enough to train a frontier model.
What you'll do
RL environments
- Build RL environments end to end: the replica systems, the planted attack, and the verifier that grades the run
- Own environment and verifier design for tool-use, web, and computer-use agents
- Make environments airtight: sandboxed, free of eval-awareness cues, and closed to reward hacking
- Read rollout traces, find where the agent took a shortcut, and close it
Task evaluation
- Own Alice's proprietary task evaluator, the engine that decides whether a task is ready for a frontier lab
- Make it the industry's sharpest quality bar for RL tasks: realism, threat-model accuracy, and training value
- Keep it learning: every customer review and every post-training run makes it stricter
Run infrastructure
- Scale the run pipeline: queue-driven runners on Kubernetes, per-run sandboxes, and a grader the agent can't reach
- Package environments so they drop into customer training and evaluation pipelines
Working with Research
- Work with researchers as one team, from a task idea to an environment that's ready to train on
- Turn what post-training runs reveal into fixes in the environments
- Review designs and code, and raise the engineering bar for the people around you
Requirements
What we're looking for
- 6+ years as a backend engineer, building production systems
- BSc in Computer Science or a related field, preferably from a leading university
- Strong Python, and production experience with Docker, Kubernetes, and cloud infrastructure (AWS preferred)
- Experience designing distributed systems and message queues
- A track record of owning systems from design to production
- High autonomy in an undefined space. You take a loose problem and come back with working code
- Fluent written and spoken English
Advantage
- Academic background in AI or machine learning: a degree, thesis, or research
- Hands-on AI engineering: building with LLMs, agents, or evaluations
- Exposure to post-training: RL fine-tuning, reward design, or rollout analysis
- Background in security, red teaming, or trust and safety
About Alice
THE CHALLENGES ALONG THE WAY
1. Being Both Strategist and Executioner
One of the hardest parts of this role is that you’re both the visionary and the builder; the one drawing the map and paving the road.
That means switching between high-level strategy and hands-on experimentation daily, and doing it while bringing others along with you. There’s no playbook for this kind of work. You’re paving an unpaved road, one small experiment at a time.
2. Balancing Security and Innovation
ActiveFence is the leading provider of security and safety solutions for online experiences, safeguarding more than 3 billion users, top foundation models, and the world’s largest enterprises and tech platforms every day.
As a trusted ally to major technology firms and Fortune 500 brands that build user-generated and GenAI products, ActiveFence empowers security, AI, and policy teams with low-latency Real-Time Guardrails and a continuous Red Teaming program that pressure-tests systems with adversarial prompts and emerging threat techniques. Powered by deep threat intelligence, unmatched harmful-content detection, and coverage of 117+ languages, ActiveFence enables organizations to deliver engaging and trustworthy experiences at global scale while operating safely and responsibly across all threat landscapes.