Tech Lead, AI Safety

Trajectory Labs, PBC; Berkeley (CA); Hybrid; USD 250,000 - 400,000; Full time

Benefits offered by this job

Health coverage

401(k) retirement plan

Visa sponsorship

Job summary

Trajectory Labs, PBC is hiring a Tech Lead to build a software factory for safety data used to train and evaluate frontier AI models. You will own complex technical problems from experiments to production, partnering with researchers to create training datasets, environments, and evaluations. This early-stage startup role values autonomy, rapid decisions, and ownership, with potential remote options for the right candidate.

Qualifications

• Candidates must demonstrate impact-driven work in frontier AI safety.
• Experience using coding agents and LLMs in development workflows.
• Ability to turn research objectives into concrete plans and deliverables.
• Comfort with the ambiguity of an early-stage startup and shifting priorities.
• Experience in AI safety or alignment contexts is preferred.
• Experience building evaluations, red-teaming systems, RL environments, or data for training models.
• Experience collaborating with frontier labs or demanding technical customers.

Responsibilities

• Lead a team of researchers and contractors to build training data, environments, and evaluation tools.
• Own methodology, architecture, production code, and quality standards.
• Partner with researchers to diagnose and improve model behavior.
• Deliver artifacts from initial experiments to reliable systems used by researchers.

Skills

Impact-driven

Agent-native engineering

Autonomy

Startup mindset

AI safety

Evals / Red-teaming

RL environments

Model-training data

Job description

Trajectory Labs is hiring a Tech Lead to build a software factory that produces safety data to train, evaluate, and improve the world's most powerful AI models. You'll partner with researchers at frontier AI labs to build training datasets, environments, and evaluations that help make their models safer.

We're looking for an experienced engineer who uses coding agents extensively and wants to own difficult technical problems, from the first experiment through to reliable systems that researchers can use.

This is an early-stage startup role, so you should expect and enjoy being in a role where responsibilities can grow and priorities can quickly change.

About us

Safety data needs to keep pace with capabilities. As AI advances, we build evaluations that measure consequential agent failures and produce training data that helps mitigate them.

A lot of companies say they use AI extensively. We mean it. PR count isn't the goal, but to give a concrete example, last week a single engineer merged 1,000 PRs.

About the role

You'll partner directly with researchers at frontier AI labs to solve crucial safety and alignment problems. You'll lead a team of researchers and contractors to build training datasets, environments, evaluations, and the tools labs need to use them. You'll own the methodology, system architecture, production code, quality bar, and final results.

Projects span both diagnosing and improving model behavior. You might build an evaluation that measures an important failure mode, or develop an RL environment or training dataset that helps correct it.

You'll work closely with our founders and the teams developing frontier models, with unusual autonomy to make consequential technical and operational decisions. The projects you lead will shape system cards, safety decisions, and how the world's most capable AI systems are trained.

What we're looking for

• Impact-driven: you want to improve the safety of frontier AI systems.
• Agent-native engineering: you use coding agents and LLMs as core development tools.
• Autonomy and judgment: you can turn a vague research objective into a concrete plan, make good trade-offs, and keep the work moving with minimal direction.
• Early-stage startup drive: you enjoy a fast pace, shifting priorities, limited structure, and taking on whatever is most important to help the company succeed.
• Experience working in an AI safety or alignment context
• Experience building evals, red-teaming systems, RL environments, or model-training data
• Experience collaborating with frontier labs or other demanding technical customers

These criteria are a guide, not a checklist. If you want to do your life's work making frontier models safer and this role excites you, we encourage you to apply.

Role details and benefits

• Reports to: Ben West, CTO.
• Location and workspace: Our team works out of Constellation in Berkeley, CA, and we prefer someone who can work alongside us there. We are open to remote for the right candidate.
• Compensation: $250,000–$400,000 plus equity. More for exceptional candidates.
• Health coverage: You'll receive a generous monthly pre-tax allowance to choose the medical, dental, and vision coverage that best fits your needs.
• 401(k): We offer a 401(k) retirement plan.
• Visa sponsorship: We sponsor visas, although we cannot successfully sponsor every visa for every role or candidate. If we make you an offer, we will make every reasonable effort to secure the visa you need, with support from an immigration lawyer we retain to guide and coordinate the process.