Conversational AI Designer (Prompt Engineer)

Fello is a profitable, hyper-growth, VC-backed B2B SaaS company building the AI Operating System for relationship-driven growth. Our platform combines data intelligence, marketing automation, and conversational AI to help businesses engage smarter, move faster, and scale effortlessly. We turn complex data into simple, intelligent actions — automating everything from outreach to follow-up. Fello isn’t another tool in the stack. It’s the system that powers them, learning, adapting, and executing in real time so professionals can focus on growth, not guesswork.

If you’re fired up about building the backbone of an AI-driven product that’s changing how professionals work, you’ll fit right in.

You’ll own how Fello’s AI talks, listens, and learns. This isn't about writing prompts in isolation. It's about listening to real conversations, understanding what makes people feel heard, and designing AI interactions that feel genuinely human while driving business results.

This is a hands-on, high-context product role that blends creativity, linguistics, and product sense. You'll work closely with our Sales, Support, and Product teams to translate real-world interactions and feedback into conversations that feel natural, effective, and human.
You're part conversation designer, part psychologist, part prompt engineer - someone who gets both the art of natural dialogue and the science of LLM behavior. 

This is a remote role open to candidates anywhere in the USA or India.

• Design and evolve conversational objectives (prompts and flows) that guide AI teammates through meaningful, goal-driven interactions.
• Listen and learn by reviewing real customer calls, tracking performance, identifying patterns, friction points, and tone mismatches, and refining prompts and flows based on real data and human feedback.
• Prototype and test conversational logic using internal tools and playgrounds, iterating quickly based on real-world interactions.
• Collaborate across teams by working hand-in-hand with Sales, Support, and Product to continuously improve how our AI interacts with customers in live scenarios.
• Shape AI personalities that sound authentically human while becoming more effective over time.
• Build scalable frameworks by developing prompt templates, tone guides, and conversation playbooks that can be reused and adapted across multiple AI agents and use cases.
• Measure and optimize through qualitative and quantitative feedback loops to assess conversation quality, engagement, and conversion outcomes.

• Conversation design experience and understand the psychology of effective dialogue, how people build trust, and what makes interactions feel natural versus forced.
• Curious and empathetic communicator who understands tone, context, and what makes people feel heard.
• Prompt engineering experience with the ability to design and optimize LLM prompts that shape tone, reasoning, and behavior across conversational AI systems.
• Business intuition to connect conversation quality with business outcomes like conversion rates, appointment setting, and customer satisfaction.
• Exceptional listening and synthesis skills to extract insights from real-world conversations and translate them into design improvements.
• Strong writing ability that is clear, natural, emotionally intelligent, and adaptable across tones and scenarios.
• Experience with evaluator prompts to assess accuracy, coherence, and conversational quality.
• Awareness of ethical AI practices including hallucination control and conversational safety principles.
• Background in Conversation Design, Linguistics, Psychology, Communication, or a related field.

• Competitive Compensation: Attractive salary and benefits package.
• Flexible Work Environment: Fully remote work with flexible hours to promote work-life balance.
• Professional Growth: Opportunities for career advancement and professional development.
• Health & Wellness: Comprehensive health, dental, and vision insurance plans.
• Paid Time Off: Generous PTO and paid holidays to recharge and relax.
• Collaborative Culture: A supportive team environment that values innovation and collaboration.
• Equity Options: Opportunity to own a part of Fello and share in our success.
• Cutting-Edge Projects: Work on innovative products that leverage AI and advanced technologies.