Senior Frontend Engineer

We're not here to add to the noise. We're here to cut through it- with AI that actually works for marketers.

From AI-powered content creation to world-class CMS and the industry's most trusted experimentation platform, Optimizely is the tool modern marketers actually want to use. AI-Ready. Set. Go.

10,000+ brands including H&M, PayPal, and Zoom already get it. So do Gartner, Forrester, and IDC, who consistently recognize us as leaders in MarTech.

But here's the thing about building great products: it takes great people. Our 1,600+ Optimizers across 12 global offices are curious, collaborative, and refreshingly human. We don't do corporate speak. We do real conversations, big ideas, and genuinely care for the work we make together.

If you want to be part of a team that's shaping the future of marketing technology — and actually enjoys doing it — you're in the right place.

Find us on Instagram: @optimizely

Introduction

This role is part of the engineering team behind Optimizely Campaign, a large-scale customer engagement and messaging platform that enables global brands to design, automate, and deliver personalized cross-channel communications at scale. The team works on high-volume, real-time systems where reliability, performance, and data-driven experiences are critical.

We are looking for a Senior Frontend Engineer to join the Campaign engineering team and help evolve the user interface of a complex enterprise SaaS product. In this role, you will play a key role in modernizing the frontend architecture, collaborating closely with Product, UX, and Backend teams, and delivering scalable, high-quality user experiences for international customers. This position is ideal for engineers who enjoy ownership, technical depth, and shaping the direction of large web applications.

Job Responsibilities

· Collaborate with an agile, cross-functional team to develop new user-facing features and enhance existing ones, adhering to clean code principles and test-driven development

· Work with the UI/UX designer and bridge the gap between UI design and technical implementation, take an active role on both sides and define how the application looks as well as how it works

· Write reusable code and libraries for future use

· Review pull requests from colleagues, offering constructive feedback

· Contribute to the modernization of an existing monolithic frontend, including transitioning from a classical technology stack (e.g. JSP, jQuery) towards a modern, component-based and micro-frontend architecture

· Collaborate closely with Product, UX/UI, and Backend engineers to implement customer-centric solutions

· Take ownership of frontend features from design through implementation and iteration

· Contribute to and follow test-driven development and frontend quality best practices

· Leverage AI-assisted development tools to improve code quality, productivity, and experimentation

Knowledge and Experience

· You count with strong general expertise in software engineering

· You have at least 5 years of professional experience developing large-scale web applications using JavaScript, React, Typescript, HTML, CSS, and various persistence technologies

· You are fluent in English (verbal and written), and have good collaboration and communication skills

· You understand the value of modern software engineering practices such as Agile, pair programming, TDD, and principles of clean code

· You are a team player with a profound practical experience in implementing large web applications in an agile, cross-functional environment

· You are able of taking ownership of complex initiatives, and drive them even from the early phases when uncertainty and risks have to tackled

· You are always thinking about the end product and how to improve the experience for users

· You like to contribute to team discussions on everything from ideation through architecture and design to implementation and support of the products and services

· You have experience configuring or maintaining CI/CD tools

· You proactively anticipate, investigate and resolve problems

· You know how to write semantic and accessible HTML, how to maintain CSS at scale, and are well-versed in JavaScript (including concepts like asynchronous programming, closures and prototypal inheritance)

· You strive to write clean and well-tested code

· You feel comfortable leveraging the type system in TypeScript or another statically-typed language

· You are proficient with React and enjoy crafting delightful and performant UIs

· You are used to working with design systems and implementing reusable components

· You have experience consuming RESTful APIs

· You demonstrate an AI-first mindset, using AI tools responsibly to support development, debugging, testing, and learning

· Ideally, you are also familiar with the Java programming language and can understand and navigate existing code

· Nice if you also have prior exposure to Piral or similar micro-frontend frameworks

Optimizely is committed to a diverse and inclusive workplace. Optimizely is an equal opportunity employer and does not discriminate on the basis of race, national origin, gender, gender identity, sexual orientation, protected veteran status, disability, age, or other legally protected status.

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