Prompt Engineer, Multi-Agent Systems at Fello

Posted on October 23, 2026

Industry: Real Estate

Job Type: Full-time

Experience Level: Mid-Senior Level

Job Description

Fello is hiring a Prompt Engineer, Multi-Agent Systems in India. The full-time role is remote and owns prompts, evaluations, and observability for the agents that power Felix, the AI teammate on Fello's real estate platform.

Responsibilities

• Design prompts for agents that work together, including what each agent knows, what it may decide, what it hands off, and what it must never do.
• Build the evaluation layer: datasets, regression suites, evaluator prompts, and scoring rubrics tied to business outcomes.
• Make the system observable with tracing, prompt versioning, datasets, experiments, and scoring, and use that data to find where agents struggle.
• Debug live interactions from traces, ship the fix, and add the case to the evaluation set.
• Choose models for reasoning, speed, and cost, and keep behavior stable when switching models.
• Design runtime prompt assembly so agents see the right live context.
• Turn vague reports of a bad interaction into a reproducible test, a fix, and a metric.

Requirements

• Hands-on experience building with large language models in production systems that real users depend on.
• Experience building datasets, writing evaluator prompts, defining rubrics, running experiments, and acting on the results.
• Fluency with LLM observability and evaluation tooling such as tracing, prompt versioning, datasets, and experiment runs.
• Experience with multi-step or multi-agent architectures, including orchestration, tool and function calling, structured outputs, and handoffs.
• Experience designing or debugging voice agents, including latency budgets, turn-taking, and real-time speech constraints.
• Comfort with prompt templating, conditional logic, and treating prompts as versioned, reviewable artifacts.
• Strong writing, because every word an agent says to a customer is a word you wrote.
• Nice to have: open-weight models, a regulated or compliance-sensitive domain, or real estate, sales tech, or high-volume outbound.

Benefits

• Competitive compensation.
• Fully remote work with flexible hours.
• Professional growth and career advancement.
• Health and vision insurance.
• Paid time off and paid holidays.
• Equity options.