Senior Engineer, Full-stack (US)

Code and Theory is seeking a Front-End Engineer to help build AI-native digital platforms and user experiences powering enterprise marketing workflows. Working closely with Engineering, Product, and Design teams, you’ll develop modern, performant, and scalable frontend applications that balance thoughtful user experience with technical excellence across web and AI-enabled systems. The Machine is the agentic operating system for marketing, built by Code and Theory. It plugs into the tools marketing teams use and turns disconnected workflows into a single intelligent system, connecting brand strategy, creative production, and media performance. The Machine helps power agencies across Stagwell's network and world-leading brands. WHAT YOU'LL DO • Build and ship frontend applications and user experiences that power AI-native digital platforms • Translate design concepts and wireframes into polished, production-ready interfaces • Partner with Product, Design, and Engineering to deliver high-quality digital experiences end to end • Create reusable components and patterns that raise consistency and development velocity across the team • Prototype and iterate quickly on new features and user experiences • Participate in code reviews, technical discussions, and the team's engineering practices • Help advance how the team builds with AI across the development lifecycle WHAT YOU'LL NEED • Strong, demonstrated experience building production frontend applications with React, Next.js (App Router), and TypeScript • Proficiency with modern component libraries and UI systems such as Radix UI, shadcn/ui, Tailwind, or similar frameworks • Solid grounding in responsive design, accessibility (a11y), frontend performance, and scalable UI architecture • Experience integrating frontend applications with headless CMS platforms and backend APIs • Familiarity with frontend tooling, Git workflows, testing practices, and CI/CD pipelines, plus analytics, SEO, and performance optimization • Strong attention to detail and design sensibility, paired with strong communication, collaboration, and problem-solving skills • Experience in agency, consultancy, or enterprise SaaS environments • Familiarity with Vercel and cloud platforms such as AWS, Azure, or GCP • Experience with data visualization libraries such as D3 or Highcharts is a plus • Comfort using AI-enabled tools day-to-day to accelerate engineering, automation, debugging, and operational work • Experience orchestrating multi-step or agent-driven AI workflows, including selecting appropriate models, tools, and execution patterns for different use cases • Strong judgment reviewing and hardening AI-assisted output for security, scalability, maintainability, and architectural fit, along with experience building prompts, evaluations, and operational context that improve engineering velocity and reliability ABOUT US Born in 2001, Code and Theory is a digital-first creative agency that sits at the center of creativity and technology. We pride ourselves on not only solving consumer and business problems, but also helping to establish new capabilities for our clients. With a global client roster of Fortune 100s and start-ups alike, we crave the hardest problems to solve. We have teams distributed across North America, South America, Europe, and Asia. The Code and Theory global network of agencies is growing and includes Kettle, Instrument, Left Field Labs, Create Group, Current, and TrueLogic. Striving never to be pigeonholed, we work across every major category: from tech to CPG, financial services to travel hospitality, government and education to media and publishing. We value the collaboration with our client partners, including but not limited to Adidas, Amazon, Con Edison, Diageo, EY, J.P. Morgan Chase, Lenovo, Marriott, Mars, Microsoft, Thomson Reuters, and TikTok. The Code and Theory network is comprised of nearly 2,000 people with 50% engineers and 50% creative talent. We’re always on the lookout for smart, driven, and forward-thinking people to join our team. The base compensation range for this role is $110,000 – $160,000 and spans multiple levels. We're open to hiring at the level that best matches the right candidate's experience. Actual compensation is influenced by a wide array of factors including but not limited to skill set, level of experience, budget, and location.