Backend Engineer

Leonar; Paris; Sur place; EUR 60 000 - 90 000; Plein temps

Résumé du poste

Leonar is seeking a Backend Engineer to build core systems for a high-trust product used by real estate and legal professionals. You will collaborate with a compact leadership team to design APIs, optimize data models, and ship AI-enabled features.

The role emphasizes reliability, code quality, and ownership, with fast feedback loops in a small team environment.

Qualifications

• 3-5 years of backend development with Python.
• Solid experience with FastAPI (or Flask).
• Strong grounding in PostgreSQL and SQLAlchemy.
• Skilled in REST API design, testing (pytest), and Git workflow.
• Familiar with Docker, Google Cloud Tasks.

Responsabilités

• Design and ship clean, well-tested REST APIs using FastAPI.
• Implement business logic for document processing and data flows.
• Design and optimize PostgreSQL schemas and queries (SQLAlchemy).
• Integrate with third-party APIs (Stripe, HubSpot, OCR/AI providers).
• Contribute to background jobs and async pipelines (Celery, Redis).
• Write tests and CI pipelines ensuring reliability at scale.

Connaissances

Python backend

FastAPI

PostgreSQL/SQLAlchemy

REST API design

Docker

Google Cloud Tasks

Outils

Flask

Description du poste

Licorne Society a été missioné par une startup IA en pleine croissance pour recruter leur Backend Engineer.

About The Company

We're building the AI copilot for notaries and real-estate professionals, automating complex legal workflows and document analysis.

Our platform combines FastAPI, PostgreSQL, LLMs, and knowledge graphs to reduce transaction times by over 80%.

Having reached early product-market fit, we’re now scaling rapidly — expanding data pipelines, integrations, and AI-powered document logic.

You’ll join a small, focused engineering team at the moment when product architecture still shapes the company’s future.

Role Overview

As Backend Engineer, you’ll build the core systems behind a high-trust, mission-critical product used daily by legal professionals.

You’ll work closely with our Lead Backend Engineer, Lead Frontend Engineer and Lead LLM Engineer to design APIs, improve performance, and ship new AI-driven features.

We iterate fast and value reliability, ownership, and clarity of thought.

What You'll Do

• Design and ship clean, well-tested REST APIs using FastAPI
• Implement business logic for document processing and data flows
• Design and optimize PostgreSQL schemas and queries (SQLAlchemy)
• Integrate with third-party APIs (Stripe, HubSpot, OCR/AI providers)
• Contribute to background jobs and async pipelines (Celery, Redis)
• Write tests and CI pipelines ensuring reliability at scale

What We’re Looking For

Core Technical Skills

• 3-5 years of backend development with Python
• Solid experience with FastAPI (or Flask)
• Strong grounding in PostgreSQL and SQLAlchemy
• Skilled in REST API design, testing (pytest), and Git workflow
• Familiar with Docker, Google Cloud Tasks

Bonus

• Integrations with Stripe, HubSpot, OCR, or AI APIs
• Experience with Azure or Google Cloud
• Background in document automation or legal tech
• Understanding of async programming and performance tuning

Mindset

• You write maintainable, production-ready code
• You thrive in fast feedback loops and small teams
• You value clarity, precision, and accountability

What You'll Get

• Impact: Build the infrastructure behind a product handling real estate transactions worth millions.
• Learning: Collaborate with senior engineers working at the frontier of AI, data, and legal tech.
• Ownership: End-to-end responsibility on features that ship fast and matter.
• Compensation: Competitive salary + stock options.