Backend Engineer (Cybersecurity)

TL;DR

Backend Engineer (Elixir/Cybersecurity): Building and optimizing an AI-powered email security product with an accent on detection logic, high-load system reliability, and seamless email integrations. Focus on analyzing millions of emails daily, designing robust relational data models, and implementing advanced AI-first development workflows.

Location: Hybrid in Paris, France (must be based in Paris or willing to relocate)

Salary: €45,000 – €100,000 a year

Company

A product-first cybersecurity company on a mission to build a global security culture through engagement, simulation, and automated threat detection.

What you will do

• Ship end-to-end features for the Slash product, including detection logic, in-email experiences, and admin tooling.
• Build robust backend systems capable of analyzing millions of emails daily with high reliability and low latency.
• Organize the backend codebase and establish engineering standards for the team.
• Research, prototype, and pitch solutions to solve complex email security challenges.
• Integrate AI-first workflows into daily development, utilizing tools like Claude Code and Codex as first-class collaborators.

Requirements

• 2+ years of experience building production-ready backend applications.
• Professional proficiency with SQL and relational data modeling.
• Must be based in Paris or willing to relocate to France.
• Serious experience and commitment to using AI coding tools in daily workflows.
• Ability to prioritize tasks to ensure speed of execution without compromising quality.

Nice to have

• Experience with Elixir and the Phoenix framework.
• Strong engineering background in Ruby, Python, or Go.

Culture & Benefits

• Work in a financially healthy, fast-growing startup with significant revenue momentum.
• Access to a dedicated AI budget and tools (Claude Max, Codex) to push the boundaries of engineering.
• Collaborative, high-standards environment with a focus on performance and passion.
• Modern office located in the heart of Paris (République / Canal Saint-Martin).

Hiring process

• Introductory call with the Talent Acquisition Manager (30 min).
• Technical system design interview with the Engineering Manager (1h).
• Take-home case study.
• Onsite cultural fit interview with the manager and a teammate (1h 30min).
• Final fit interview with the CTO (30 min).