Lead Full Stack Engineer

Genies; Pays de la Loire; Hybrid; EUR 90,000 - 130,000; Full time

Benefits offered by this job

Equity

Health insurance

Unlimited PTO

Parental leave

Hybrid work structure

Wellness reimbursement

Job summary

Genies is seeking a contract Lead Full Stack Engineer to guide architectural direction for avatar-driven products. You’ll mentor engineers while contributing hands-on work across frontend and backend, using React, Next.js, TypeScript, Node.js, and Go.

You’ll collaborate with product and design to deliver scalable, AI-enabled web solutions in a fast-paced environment. You will drive engineering best practices, security, and observability, balancing leadership with hands-on coding to ship complex

Qualifications

• 7+ years of full-stack development experience with leadership or mentoring roles.
• Bachelor's degree in Computer Science or related field.
• Proven ability to design and scale distributed, high-performance web apps.
• Expertise with React, TypeScript/JavaScript, Node.js, Next.js.
• Strong frontend usability focus and design sensibilities.
• Strong backend with Go or Python; databases including NoSQL/SQL.
• RESTful and GraphQL APIs, event-driven architectures knowledge.
• Security fundamentals: OWASP, OAuth 2.0; AWS + CI/CD experience.
• AI workflow maturity and ability to apply AI tools effectively.
• Excellent communication; capable of leading technical and non-technical discussions.

Responsibilities

• Define architectural vision for full-stack systems and scalable frameworks.
• Mentor and coach engineers; perform code reviews and provide feedback.
• Contribute hands-on to code with emphasis on reliability and performance.
• Develop intuitive frontend UI with high standards and robust APIs.
• Collaborate with product, design, and other teams to plan deliverables.
• Drive developer velocity, observability, and security practices.

Skills

React

TypeScript/JavaScript

Go

Python

REST/GraphQL

AWS

CI/CD

Distributed systems

Communication

Education

Bachelor's degree in Computer Science

Tools

AWS

CI/CD pipelines

GraphQL

Job description

Genies is an AI avatar technology company powering the visual and embodiment layer for AI. Through the Genies SDK, their proprietary avatar framework brings AI to life as fully realized AI personas that look, think, behave, and play like living identities. Genies powers AI companion, NPC, and agent use cases across enterprise, consumer, creator, entertainment, and gaming. Genies has raised $200M from Silver Lake, BOND, and Bob Iger. Genies is built on the belief that every website, app, game, brand, and human will have an AI persona.

Overview

Genies is seeking a contract Lead Full Stack Engineer to guide the technical direction, architecture, and execution of our avatar-driven digital products. You'll be a player-coach — leading by example as a hands-on contributor while mentoring a team of talented engineers. Reporting directly to the Director of Software Engineering and Infrastructure, you'll drive technical excellence, champion engineering best practices, and ensure scalable, performant solutions across the stack.

This is a high-impact role for an engineer who thrives on mentorship, system design, and building cohesive teams that ship complex, user-facing systems at the intersection of AI, game technology, and UGC creation tools. We move fast at Genies, and we expect our lead engineers to move fast with us — leveraging AI as a force multiplier while holding the bar on quality, clarity, and correctness.

What You'll Be Doing

Technical Leadership — Define and own the architectural vision and implementation strategy for full-stack systems supporting Genies' Smart Avatar ecosystem. Establish technical standards, patterns, and scalable frameworks across both frontend and backend. Make opinionated choices on separation of concerns and push back on overengineering.

AI-Augmented Development — Actively integrate AI tools into your development workflow for planning, code generation, debugging, and testing. Critically evaluate AI-generated output — catching complexity, duplication, or architectural drift before it takes root. Beyond your own practice, you'll champion AI adoption across the team: identifying opportunities where AI can reduce toil, accelerate delivery, and raise the quality bar. You'll share workflows, prompt strategies, and tooling discoveries that make the whole team faster — not just yourself.

Hands-on Contribution — Contribute directly to the codebase with a focus on maintainability, reliability, and performance. Build intuitive, interactive user interfaces to a high frontend standard while also delivering robust APIs and backend services using technologies such as React, Next.js, TypeScript, Node.js, and Go.

Mentorship & Team Development — Act as a player-coach for a growing team. Provide structured mentorship, code review guidance, and ongoing feedback that fosters career growth and engineering excellence.

Cross-Functional Collaboration — Partner closely with product managers, designers, and other engineering teams to translate high-level goals into technical deliverables. Ask sharp questions during requirements gathering and translate ambiguity into clear implementation plans.

Strategic Impact — Drive initiatives that improve developer velocity, operational efficiency, and code quality. Proactively identify technical risks, scalability challenges, and long-term architectural needs — including tradeoffs in distributed systems, CAP theorem considerations, and service design.

Process & Culture Building — Champion best practices in code quality, security (OWASP Top Ten, OAuth 2.0), testing (TDD/automation coverage), and observability (alerting and monitoring). Help shape a culture of learning, accountability, and high ownership.

What You Should Have

• 7+ years of professional full stack development experience, including at least 2 years in a technical leadership or mentorship role
• Bachelor's degree in Computer Science, a related field, or equivalent practical experience
• Proven ability to design and scale distributed, high-performance web applications
• Expertise with modern web technologies: React, TypeScript/JavaScript (ES6+), Node.js, Next.js
• Strong frontend sensibility — you care about usability, design patterns, and the details that make an interface feel right
• Strong backend development experience with Go, Python, or similar languages
• Fluency with NoSQL and relational database solutions
• Experience building and consuming RESTful and GraphQL APIs; familiarity with event-driven architectures
• Understanding of data pipelines and ETL patterns
• Solid grasp of security fundamentals: OWASP Top Ten, OAuth 2.0
• Experience with cloud infrastructure (AWS) and CI/CD pipelines
• Demonstrated AI workflow maturity — you use AI tools to increase output and can articulate when and how you apply them, not just that you do
• Strong communication skills with the ability to lead both technical and non-technical discussions
• Demonstrated ability to balance hands-on engineering with people leadership
• Ability to navigate fast-paced environments with shifting priorities while maintaining code quality and design standards

Bonus

• Experience with real-time systems, WebSockets, or multiplayer architectures
• Exposure to AI/ML systems, LLM integration, or digital identity platforms
• Familiarity with 3D pipelines, image processing, or model-building workflows
• Passion for mentoring, technical strategy, and cultivating a high-performing team culture

How Genies will support you

• Competitive salary and equity packages
• Comprehensive health, dental, and vision insurance
• Unlimited PTO
• Parental leave
• Hybrid work structure (minimum 4 days in office weekly)
• Monthly wellness reimbursement

Genies is a well-funded, fast-growing start-up that values innovation, creativity, and ownership. Our roles and their responsibilities are created with a breadth of scope that introduces each employee to exciting new challenges and opportunities that a growing start-up encounters. The actual base pay is dependent upon a number of factors, including: professional background, training, transferable skills, work experience, education, location, business and product needs, and market demand. The base pay range is subject to change and may be modified in the future. These are for our full time, benefits eligible positions