Backend Software Engineer (Core AI)

At Goodweek, we're building a next-generation AI tool designed to revolutionize business productivity. We are focusing on delivering a secure, scalable, and reliable system that supports real business use cases across different departments. The goal is to make AI practical, controlled, and truly embedded in how modern organizations operate.
Our team spans across France, Spain, and the United States, and our vision is backed by 6 international investment funds.
To accelerate our growth, we're looking for a talented Software Engineer to join our Engineering team and help us build an innovative product that will make a real impact on how thousands of users work every day.
Tasks
About the role
As a Backend Engineer, you'll work on the core infrastructure that makes our AI platform fast, reliable, and scalable.
You'll be joining the Core AI team, responsible for the foundational layer of our AI product, covering orchestration, memory, low-level security, and system harness.
This is a role for someone who thrives at the intersection of backend engineering and applied AI, thinking about latency, reliability, and model behavior all at once.
What you'll do
You'll be tackling challenges across:

• AI orchestration: owning the core layer that coordinates AI workflows, model calls, multi-step reasoning, and multi-agent delegation, including RAG pipelines and knowledge bases
• LLM integration: integrating and tuning new LLMs into a production-grade backend, with a focus on security, guardrails, and evaluation (latency, response quality)
• Data ingestion & export: building robust pipelines and services to handle a variety of file formats reliably and at scale
• Context & token optimization: designing strategies to maximize LLM efficiency, manage context windows, and keep costs in check
• Infrastructure & observability: designing scalable APIs, automating deployment pipelines, monitoring, and testing to keep the platform reliable and performant
• Architecture & engineering culture: participating in tech stack decisions, documenting technical knowledge, and continuously driving innovation across the AI platform

Requirements
Technical background

• 5+ years of experience with Node.js + TypeScript stack
• NestJS/React and PostgreSQL are a plus
• Hands-on experience (or strong familiarity) with AI/ML integration (LLMs, RAG, or similar)
• Solid understanding of backend architecture, scalability, and security best practices
• Experience with databases, authentication, and cloud platforms (AWS)
• Familiar with CI/CD, Git workflows, and agile methodologies
• Bonus: familiarity with other backend programming languages applied to AI (Python, Go...)

Soft skills

• Strong technical communication
• Agile mindset focused on product and business value
• Ability to document and defend architectural decisions
• Balance between code quality and delivery speed
• Technical English required

Benefits

• Health insurance provided by the employer
• Meal vouchers and transportation cost reimbursement (50%)
• Flexible working hours
• Hybrid remote work
• Daily use of English through close collaboration with teams in the US and Spain