Senior Full-stack Engineer

Role Description

We specialize in managing and maturing production web applications for our clients, and we seek engineers who thrive when owning a feature long after its initial launch. As a Senior Fullstack Engineer focused on stability and evolution, you will work across React / Next.js and Node / TypeScript to maintain, stabilize, and enhance features to ensure they remain reliable in production environments.

You will operate within a Monks delivery team, collaborating with clients and product stakeholders to take real ownership of the long-term health of a production-deployed solution. We are pioneers in agentic engineering for maintenance; you will use tools like Claude Code and Codex daily to refactor, optimize, and scale existing codebases. We are looking for individuals who are fluent in working alongside AI coding agents to guarantee the long-term stability and performance of established systems.

Qualifications

• 5+ years of experience maintaining and scaling high-traffic, full-stack web applications.
• Strong TypeScript proficiency, specifically in improving React/Next.js frontends and Node backends.
• Proven experience in API optimization and database performance tuning.
• Hands-on experience ensuring stability and scale on AWS.
• Disciplined testing habits and an eye for highly maintainable, readable code.
• Strong English communication skills for effective client and team collaboration.
• Comfort working in a fast-paced, agile consulting environment focused on delivery excellence.

Requirements

• Maintain, optimize, and evolve features across the frontend (React / Next.js) and backend (Node / TypeScript).
• Refactor and scale APIs while optimizing the underlying data models to support growth.
• Review code and monitor production telemetry to ensure ongoing quality and consistency.
• Collaborate with product, design, and other engineers to ship refinements end-to-end.
• Troubleshoot and resolve production issues to maintain high availability.
• Contribute to the team's evolving standards, tooling, and maintenance practices.

Benefits

• Experience working on AI-heavy products or integrating LLMs into existing workflows.
• Deep expertise in PostgreSQL optimization and management.
• Experience maintaining or expanding an established design system.
• Familiarity with CI/CD and DevOps practices to streamline production updates.
• Open-source contributions or maintenance work you are proud to share.

Company Description

Monks is the global, digital-first, data-driven, unitary operating brand of S4 Capital plc. With a legacy of innovation and specialized expertise, Monks combines an extraordinary range of global Marketing and Technology Services to redefine how brands interact with the world. Through Monks.Flow, its flagship AI ecosystem for marketing orchestration, Monks transforms marketing into a growth engine, collapsing timelines and connecting brands to culture in real time.

We are an equal-opportunity employer committed to building a respectful and empowering work environment for all people to freely express themselves amongst colleagues who embrace diversity in all respects.