Senior Software 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, Pay Pal, and Zoom already get it. So do Gartner, Forrester, and IDC, who consistently recognize us as leaders in Mar Tech.

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

Long Description We're looking for a Senior Software Engineer to join one of our Content Management System (CMS) product teams in the UK, working on a key part of the Optimizely platform.

Our CMS is one of the core products in the Optimizely ecosystem. It enables businesses to create, manage, and publish digital content—such as websites, landing pages, and product experiences—across multiple channels. It works alongside other parts of the platform, including experimentation, campaign management, and data services, to support end-to-end digital experience creation and optimization.

We offer both PaaS and SaaS versions of our CMS and are continuously evolving it to be more scalable, composable, and developer-friendly. As part of this team, you'll help build and evolve core CMS capabilities while contributing to the long-term direction of the platform.

Introduction About the Team Our team focuses on building extensible CMS capabilities and integrations that make the platform more flexible and useful for customers. This includes developing add-ons such as:

Forms – a flexible form-building capability that allows users to create and manage dynamic forms based on predefined UX layouts, without requiring developer involvement. Forms can be structured using rows, columns, and reusable elements, enabling editors and marketers to quickly build and update forms while still supporting advanced customization when needed.

Language Manager – enabling editors to work efficiently with multilingual contentAI tools & agents – we are building AI-powered capabilities to streamline how forms and content experiences are created and managed. This includes generating forms dynamically from design inputs (e.g., Figma) or user intent, reducing manual composition while applying best practices by default. We also explore using agents to connect our add-ons with other parts of the ecosystem (e.g., Campaign, Optimizely Data Platform), helping automate workflows, reduce friction, and enable more seamless data flow across systems.

These capabilities are supported by the Opal Orchestrator platform, which underpins how AI-driven workflows are designed and executed across the  addition, we integrate the CMS with external systems and services, helping it fit into a wide range of customer architectures. This includes ingesting data from other Optimizely products and enabling seamless data flow into marketing automation systems to support high-impact campaigns.

A significant part of our work involves designing and maintaining REST APIs that expose CMS functionality and enable flexible, composable use of the platform.

Our CMS is not just a product—it's also a platform used and extended by a global developer community. Customers and partners build custom solutions, integrations, and extensions on top of it. Because of that, we place strong emphasis on clean, well-structured code, clear abstractions, and solid separation of concerns. We aim to provide stable APIs and extension points that make the platform easy to customize and build upon.

You'll be joining a group of experienced engineers with deep product knowledge and diverse technical backgrounds. While engineers on this team are based in Hanoi, Vietnam, the wider CMS organization spans…