Senior Founding Engineer (Python & AI/LLM)

We are looking for a Senior Founding Engineer to own the engine behind our autonomous sales CRM.

At Sellence, we are building AI agents capable of conducting real-time negotiations, understanding customer needs, and closing deals independently. The core of our challenge is engineering a system that masters the art of persuasion and complex sales logic.

You will take ownership of the backend architecture and AI orchestration, playing a pivotal role in translating these sophisticated human interactions into robust, high-performance code.

This is an opportunity to lead the development of an agentic engine at the forefront of the AI revolution.

Responsibilities

• Architect high-throughput backend services using FastAPI, ensuring the low latency required for seamless, real-time sales conversations.
• Engineer stateful agentic workflows, optimizing the decision-making logic, prompt chains, and memory management of our autonomous agents.
• Lead our RAG and LLMOps strategies, from optimizing vector search to establishing rigorous evaluation pipelines for conversation quality.
• Own the database and data modeling layers, writing optimized SQL to support complex analytics and real-time AI decision-making.
• Drive technical excellence by mentoring team members and partnering with Product to shape a scalable technical roadmap.

What we are looking for

• Proven track record in at least 2 technology companies, where you played a significant role in architecting production-grade Python systems.
• Solid academic foundation with a BSc or MSc in Computer Science (or equivalent engineering experience).
• Deep expertise in FastAPI and Asynchronous programming, with a focus on building scalable and resilient backend architectures.
• Expert-level SQL skills and significant experience designing complex schemas for PostgreSQL.
• Hands-on experience building production-grade LLM applications, including RAG architectures and vector databases.
• Technical leadership mindset, you are a self-starter who values clean code, professional resilience, and direct communication.