Research Engineer

Ersilia; San Francisco (CA); On-site; USD 150,000 - 190,000; Full time

Job summary

Ersilia is hiring an Agent Product Engineer to build high-taste products for self-learning agents. This role focuses on scaling the product, delivering exceptional user experience, and owning a majority of agent infrastructure with a baseline full-stack skill set.

The candidate should have 3–7 years of engineering experience, a background in building/designing agents, strong communication with customers, and willingness to relocate to San Francisco with five days in the FiDi office.

Qualifications

• 3–7 years of engineering experience.
• Prior experience building and designing agents (Applied AI or agent engineering background).
• Solid product engineering capabilities and end-to-end feature shipping.
• Strong customer-facing communication skills and ability to explain complex concepts.

Responsibilities

• Build high-taste agent products with consumer-grade UX polish.
• Design and ship agent capabilities from 0 to 1 in a fast-scaling product surface.
• Contribute across the full stack with focus on agent infrastructure and product.
• Translate customer feedback into concrete product iterations.
• Collaborate as the team grows and maintain high product taste.

Skills

Agent design

Full-stack

Customer communication

Relocation ready

TypeScript

Tools

TypeScript

Job description

About The Client

Our Client builds infrastructure for Agent Behavior Monitoring (ABM). While traditional observability focuses on logging exceptions and latency, our ABM surfaces behavioral anomalies, such as instruction drift and context retrieval loss, in production at scale.

Hundreds of teams building autonomous agents rely on Judgment to understand how their systems are behaving post-deployment. Instead of reactive incident triage, they cluster patterns across conversations and workflows, correlate regressions to specific interaction types, and pinpoint where reliability breaks down in their usage context.

They’ve raised $30M+ across two rounds in the past five months. Their investors include Lightspeed, SV Angel, Valor Equity Partners, Nova Global, Chris Manning, Michael Ovitz, Michael Abbott, Cory Levy, Kevin Hartz, and others.

About the Role:

They are hiring an Agent Product Engineer to build high-taste products for self-learning agents. This role is crucial for scaling the product to meet customer demand and maintaining a reputation for exceptional user experience in the rapidly evolving AI agent space. The right person is passionate about improving agent behavior and can contribute to a product that is both powerful and a joy to use. The role is majority agent work with a baseline of full-stack engineering required. Candidates can come from a front-end/design engineering background or an AI engineering background, but both must have prior experience building and designing agents, preferably at a startup with 0-1 product ownership.

What You'll Own

• Build high-taste agent products that pair powerful behavior with consumer-grade UX polish
• Design and ship agent capabilities from 0 to 1 inside a fast-scaling product surface
• Contribute across the full stack as needed, with the majority of work focused on agent infrastructure and product
• Translate customer feedback on agent behavior into concrete product iterations
• Help raise the bar on product taste and craft as the team grows past 19 people

Requirements

Must-Have

• 3-7 years of engineering experience
• Prior experience building and designing agents (Applied AI or agent engineering background), production work, not hackathon projects
• Solid product engineering capabilities, ships features end-to-end
• Strong customer-facing communication skills, comfortable explaining complex technical concepts, and building trust with technical and non-technical stakeholders
• Comfort with 0-1 product work and ambiguity
• Basic full-stack engineering ability
• Based in SF or willing to relocate, 5 days in office in FiDi

Nice-to-Have

• Prior evals, observability, or behavior-monitoring product experience (heavily preferred)
• TypeScript fluency
• Prior Series A or seed startup experience
• Strong design taste at consumer-grade product polish levels
• Front-end or design engineering range on top of agent work