Who you are

- Deep front-end expertise. Expert command of HTML, CSS, JavaScript/TypeScript, accessibility, and web performance, plus several years building production applications

- Proven web experimentation & CRO expertise. Hands-on experience architecting and shipping complex A/B, Multivariate Testing, and personalized web experiments with measurable conversion outcomes

- Experience with web experimentation and feature flag platforms (e.g. Kameleoon, Optimizely, VWO, LaunchDarkly) and product analytics tools (e.g. Amplitude, GA4)

- Strong Jamstack and modern front-end stack. Mastery of Next.js, React, TypeScript, and up-to-date rendering strategies with a focus on performance and accessibility

- Experience working within a design system or maintaining a shared component library

- Versatile CMS background (Headless Sanity & WordPress/Twig).

Experience modeling content in headless CMS platforms (Sanity/Contentful) alongside hands-on proficiency in traditional WordPress, PHP, and Twig templates

- Hands-on AI-assisted development. You actively use AI coding tools in your day-to-day work and have a point of view on where they help, where they don't, and how to use them responsibly
- A growth and experimentation mindset. You're comfortable building for measurement and iteration, and you care about the business outcome your code drives

- Technical leadership without ego. You set standards and mentor others while staying collaborative and open to better ideas

- Robust communication. You collaborate easily with both technical and non-technical partners — designers, marketers, and CRO

- Ambitious and humble. You don't accept the status quo simply because "it's what we've always done" — you push for better, newer, more innovative approaches while staying grounded

- Comfort in the grey areas. You're adaptable, can prioritize amid ambiguity and changing priorities, and break large, complex problems into shippable pieces

- Back-end familiarity.

Comfort working beyond the front end: integrating APIs and services, or background experience with full-stack development





- Experience collaborating closely with designers in Figma

What the job involves

- We're looking for a Senior Front-End Developer with deep web experimentation experience — to drive high-velocity A/B and multivariate testing across our web properties while elevating our technical architecture

- You'll work across our modern Jamstack stack (Next.js, Sanity headless CMS, React, TypeScript) as well as our traditional headful WordPress platform (PHP, Twig templates), expanding our component libraries and engineering high-performance CRO frameworks.

- CMS familiarity is essential: you'll build and optimize features across both contemporary headless APIs and legacy PHP/Twig codebases

- This is a senior individual-contributor role with real technical influence: you'll set experimentation standards, mentor developers, and partner with the Engineering Manager on quality and site performance

- Just as importantly, we want someone who treats AI-assisted development as a core engineering skill

- We're actively reshaping how we build — using AI coding agents, MCP-connected tooling, and automated workflows to move faster without sacrificing quality — and we want this person to help lead that evolution, not just keep up with it

- Engineer across a hybrid web stack — ship production features in Next.js, Sanity, and React with TypeScript, alongside ongoing support and enhancements for our headful WordPress (PHP/Twig) environment across getjobber.com

- Contribute to and extend our shared component library and design system so the team builds faster on consistent, reusable, well-tested foundations

- Own performance and accessibility as first-class requirements — Core Web Vitals,



semantic and accessible markup, and fast, resilient page loads that directly support conversion

- Work seamlessly between headless and traditional CMS architectures — integrate APIs and structured content in Sanity while maintaining Twig-templated components in WordPress as we transition our web ecosystem

- Write well-tested, scalable, well-organized code and drive consistent engineering practices through code review

- Collaborate with our other developers on best technical practices and project decisions

- Use AI coding tools and agents fluently (e.g. Claude, AI-assisted IDEs, agentic workflows) to accelerate development while keeping a critical eye on output quality and reliability

- Improve how the team works with AI — building and refining MCP integrations, prompts, and context so our tickets, content, and codebase are AI-ready

- Help define and benchmark team standards for AI-assisted development — identifying what works, documenting it, and raising the whole team's baseline

- Architect and execute complex A/B and multivariate experiments across high-converting marketing flows, partnering with CRO leads and data analysts to design statistically sound, performant test variants

- Build for experimentation velocity and statistical integrity — minimize flicker, ensure client/server-side rendering accuracy, and reduce time-to-market from test hypothesis to live variant

- Support SEO, LLM, and AI-search initiatives with the technical foundations (structured data, performance, rendering) that keep the site discoverable as search evolves

- Set patterns and technical direction for how we build, and bring the team along through pragmatic, well-reasoned decisions

- Mentor and coach other front-end developers, lifting their skills and holding the team to its engineering principles

- Partner with the Engineering Manager on technical standards, code quality, and architecture

- Identify and act on opportunities to improve the stack, tooling, and processes, and maintain strong team documentation

📌 Senior Front-End Developer (Toronto)
🏢 Jobber
📍 Toronto