Fullstack Engineer – AdManager, Freelance

Role Overview

• Design, build, and evolve core AdManager features across campaign setup, reporting, onboarding, creatives management, payments, account management, and AI-powered workflows
• Own complex initiatives from conception to production with minimal supervision
• Translate ambiguous product needs into clear technical plans, milestones, and production-ready features
• Collaborate closely with product managers, engineers, and business stakeholders to deliver high-quality advertiser experiences
• Build and maintain robust user-facing experiences using Next.js, React and Typescript
• Design scalable APIs, services, database schemas, and domain models that remain maintainable as the platform grows
• Work with PostgreSQL and backend systems to support reliable advertiser workflows and reporting experiences
• Apply strong engineering practices, including testing, clear architecture, and thoughtful code reviews
• Ship features with appropriate monitoring, logging, alerting, analytics, and observability
• Investigate, debug, and resolve production issues for the systems you build
• Contribute to incident response and postmortems with clear communication and ownership
• Improve codebase maintainability, documentation, conventions, and developer experience beyond your assigned tickets
• Understand advertiser workflows and proactively identify better product or technical solutions
• Challenge weak assumptions and propose pragmatic alternatives that balance speed, business impact, and long-term quality
• Use AI-assisted development workflows to accelerate delivery while maintaining a high bar for correctness and maintainability
• Contribute positively to a shared codebase and a collaborative, low-ego engineering culture.

Requirements

• Strong experience shipping production-grade fullstack software, especially with Next.js, React, Typescript, backend APIs, and PostgreSQL
• Proven ability to own projects end-to-end, from problem definition to rollout, monitoring, and long-term maintenance
• Strong backend engineering fundamentals: API design, architecture, testing, data modeling, and system design
• Ability to independently build and evolve complex user-facing experiences
• Comfort operating in ambiguity, breaking down initiatives, identifying dependencies, managing risks, and keeping delivery momentum
• Strong instincts for code quality, maintainability, and pragmatic technical decision-making
• Experience taking responsibility for production systems, including monitoring, debugging, incident response, and postmortems
• A collaborative, low-ego mindset and clear communication style, especially during project delivery and production issues
• A strong sense of urgency, with the judgment to move fast without sacrificing reliability or long-term maintainability.

Tech Stack

• JavaScript
• Next.js
• Postgres
• React
• TypeScript

Benefits

• Hybrid flexibility — We're in the heart of Paris.
• Annual offsite — The whole team, once a year, somewhere worth the trip.
• Tech Syncs — Engineering and Product meet in person at least quarterly, worldwide.