Senior Full Stack Developer

The Role: Senior Software Developer, Editor

We're looking for an experienced full-stack developer to join the team behind Knak's editor, where marketers design on-brand emails and landing pages without writing code. It's a complex, stateful application: a structured document model, a canvas that renders it live, reusable and lockable modules, translations, version history, and realtime collaboration so whole teams can build together.

You'll work across the entire editor and take ownership of our realtime collaboration engine: the CRDT-based sync layer, running on Cloudflare Workers and Durable Objects, that lets multiple people, and increasingly AI agents, edit the same asset at once. This is a hands-on role for someone who loves hard frontend architecture and isn't afraid of the distributed-systems problems underneath it. You'll also contribute to architecture decisions, mentor teammates, and work with product and design to shape how marketers create.

What You'll Be Doing

• Build the editor: Design and ship features across our Vue 3 and TypeScript editor, including the canvas, attribute panels, undo/redo, selection, modules and locks, and translations. Keep it fast and correct on large, complex designs.
• Own realtime collaboration: Evolve and scale our multi-user editing engine (CRDTs, WebSockets, and Cloudflare Workers with Durable Objects). Harden it against reconnects, stale clients and partial failures, and make sure every editor feature behaves correctly when several people are editing at once.
• Evolve the document model: Extend the structured document format behind every asset, and the pipeline that turns it into production-ready email and landing-page HTML.
• Enable AI-driven editing: Partner with our AI team so agents can edit designs through the same operations and sync model as people.
• Build reliable APIs: Develop and maintain the Laravel (PHP) APIs and persistence behind the editor, with a focus on testability, observability and performance.
• Own it in production: Instrument, monitor and roll out changes safely with feature flags, and debug issues end to end, from the browser through the edge to the database.
• Elevate code quality: Lead design and code reviews, write down architectural decisions, and keep the bar high.
• Collaborate and mentor: Work with product, design, QA and DevOps, and share deep knowledge of the editor so the whole team can work on it confidently.

What You Should Bring

• 6+ years of software development experience, with significant full-stack work
• Experience building complex, stateful, editor-style web applications, such as design tools, page builders, or rich-text or canvas editors
• Deep expertise in TypeScript and a modern frontend framework (Vue 3 preferred), including reactivity internals, state management and performance tuning
• A product mindset: you care about the marketers using the editor, push back on requirements when there's a better solution for them, and judge your work by whether it solves their problem, not just by whether it shipped
• A progressive, hands-on approach to AI in your own workflow, using coding agents and AI tools every day to move faster, and with the judgment to review, test and own everything they produce
• Strong web fundamentals: JavaScript, HTML, CSS, the DOM, browser storage, rendering performance and profiling
• Solid backend experience with PHP/Laravel or a comparable framework, plus MySQL
• A good grasp of distributed-systems concepts such as consistency, idempotency, ordering and failure handling
• Production experience with realtime systems such as WebSockets, presence and reconnection
• Expertise in RESTful APIs, TDD and CI/CD (GitHub Actions)
• Excellent problem-solving skills, strong written communication and a collaborative mindset

Nice to Have

• Experience with collaborative editing technology (CRDTs or OT, e.g. Yjs, Automerge, Loro)
• Experience with edge or serverless runtimes (Cloudflare Workers, Durable Objects, AWS Lambda)
• Email HTML rendering or cross-client compatibility experience
• Experience integrating LLMs or AI agents into product features
• Prior experience in a fast-growing SaaS company

Base Salary

The anticipated base salary range for this position is $130,000 – $160,000/year. Final compensation will be determined based on factors including relevant experience, skills, qualifications, and internal equity. This range reflects base salary only and does not include other forms of compensation that may be available as part of the total rewards package.