Fullstack Developer - Creative Tool for Artists and Designers

Madfish; United Kingdom; Remote; GBP 60,000 - 90,000; Full time

Job summary

A creative technology company in the United Kingdom is seeking a Fullstack Developer to enhance its intelligent canvas platform for artists. This role requires over 5 years of experience in fullstack development, with a strong background in TypeScript and Next.js. Responsibilities include building new features and optimizing performance for users, alongside a focus on clean architecture and scalability. The position offers competitive salary, equity options, and a remote-friendly work environment.

Benefits

Competitive salary + equity/stock options

Remote-friendly work environment

Work on cutting-edge AI tools

Qualifications

• 5+ years of professional fullstack development experience.
• Strong TypeScript expertise with strict mode compliance.
• Production experience with Next.js and Node.js backend.

Responsibilities

• Build and maintain features across the full stack.
• Design and implement API endpoints following architectural principles.
• Optimize performance for concurrent users.

Skills

Fullstack development experience

TypeScript expertise

Next.js production experience

Node.js backend skills

SQL optimization

REST API design

Git workflow proficiency

Problem-solving skills

Tools

PostgreSQL

Docker

Redis

GCP Cloud Run

Vercel

Job description

About the Role

We're seeking an experienced Fullstack Developer to join the Genie team and help build an intelligent canvas platform that enables artists and creators to build custom, node-based creative workflows combining AI models with professional editors.

This is a critical hire to strengthen our development capacity and accelerate platform development with clean architecture, scalability, and maintainability.

Tech Stack

Frontend

• Next.js 15.5+ (App Router with Turbopack, React Server Components)
• React 19.2 with TypeScript
• TailwindCSS + custom design system
• Zustand for state management
• WebGL & WebGPU canvas rendering (GPU-accelerated graph visualization)
• GLSL shaders for visual effects and rendering
• Storybook 9+ for component development

Backend

• Fastify 4+ (Node.js framework) - high-performance REST APIs
• TypeScript 5.4-5.8 (strict mode with verbatimModuleSyntax)
• Hexagonal Architecture (Ports & Adapters pattern)
• Turborepo monorepo with pnpm workspaces (serial builds for architecture stability)

Data Layer

• PostgreSQL (via Prisma ORM) - users, projects, billing, subscriptions
• Redis - caching, BullMQ queues, pub/sub, rate limiting
• Neo4j (active) - canvas/node graph data with hexagonal adapter
• Google Cloud Storage - asset management

Infrastructure & DevOps

• GCP Cloud Run - microservices hosting
• Vercel - frontend deployments with preview environments
• Docker - containerization & local development
• Cloudflare - DNS, CDN, WAF
• GitHub Actions - CI/CD pipelines

Key Libraries & Tools

• Better Auth 1.3+ - authentication & session management
• BullMQ - background job queues
• Zod 4.1+ - schema validation with branded types
• Sentry - error tracking
• PostHog - analytics
• Stripe - payments
• Winston - structured logging
• Resend - transactional emails
• elkjs - graph layout algorithms

What You'll Do

Core Responsibilities

• Build and maintain features across the full stack (Next.js frontend + Fastify backend)
• Design and implement API endpoints following hexagonal architecture principles
• Work with PostgreSQL, Redis, and Neo4j using the repository pattern
• Implement background jobs using BullMQ for async operations
• Build GPU-accelerated canvas components using WebGL/WebGPU
• Write and optimize GLSL shaders for visual effects and rendering
• Develop creative coding features for visual artists and creators
• Integrate AI models (Stable Diffusion, ComfyUI workflows, etc.)
• Develop reusable components in Storybook for our design system
• Write clean, maintainable, and testable TypeScript code with strict mode
• Follow architectural patterns: Ports & Adapters, Schema-First Development
• Collaborate on API design and database schema changes
• Optimize performance for 1000+ concurrent users
• Debug production issues and implement monitoring solutions

Technical Expectations

• Follow hexagonal architecture (business logic → Port interface → Adapter implementation)
• Use schema-first development with centralized Zod schemas and branded types
• Implement proper separation of concerns across monorepo packages
• Write code with TypeScript strict mode compliance (verbatimModuleSyntax, exactOptionalPropertyTypes)
• Use ENV_KEYS registry for all configuration (no .env files allowed)
• Apply queue-first approach for background jobs (BullMQ)
• Use repository pattern for database access (DatabaseFactory + Repository Adapters)
• Write meaningful tests with proper package imports (never relative imports in tests)
• Understand GPU rendering pipeline (WebGL/WebGPU for canvas visualization)
• Work with AI model APIs and understand image generation workflows

Required Skills

Must Have

• 5+ years professional fullstack development experience
• Strong TypeScript expertise (generics, type inference, strict mode, branded types)
• Production experience with Next.js (App Router strongly preferred)
• Solid Node.js backend development skills (Fastify/Express/Koa/similar)
• Experience with PostgreSQL and SQL optimization
• Understanding of REST API design and best practices
• Familiarity with monorepo architecture (Turborepo, Nx, Lerna, or similar)
• Git workflow proficiency (feature branches, PRs, code reviews)
• Strong problem-solving and debugging skills
• Ability to work independently and take ownership of features

Highly Desired (Creative Coding & AI)

• Creative coding experience (p5.js, Three.js, Processing, or similar)
• WebGL/WebGPU experience (shader programming, GPU optimization)
• GLSL shader programming (vertex shaders, fragment shaders, compute shaders)
• ComfyUI experience or understanding of node-based AI workflows
• Working knowledge of AI image generation models (Stable Diffusion, FLUX, etc.)
• Understanding of AI model parameters (prompts, sampling, CFG, schedulers, etc.)
• Experience with generative art or interactive graphics
• Familiarity with canvas-based creative tools

Nice to Have

• Experience with Hexagonal/Clean Architecture or similar patterns (Onion, Ports & Adapters)
• Familiarity with graph databases (Neo4j, ArangoDB, etc.)
• Redis experience (caching, pub/sub, queues)
• GCP knowledge (Cloud Run, Cloud SQL, Cloud Storage, Secret Manager)
• Docker and containerization experience
• Experience with BullMQ, Bull, or similar queue systems
• Understanding of authentication systems (OAuth, session management)
• Payment integration experience (Stripe)
• Exposure to AI/ML APIs (OpenAI, Replicate, fal.ai, RunPod)
• Storybook experience for component-driven development
• Vercel deployment and preview environments
• Experience with creative coding frameworks (openFrameworks, Cinder, nannou)
• Knowledge of image processing and computer graphics fundamentals

What We're Looking For

Key Qualities

• Pragmatic approach - you prioritize correct solutions over quick hacks
• Architecture-minded - you understand why patterns matter at scale
• Detail-oriented - you care about code quality, testing, and documentation
• Self-sufficient - you can unblock yourself and find solutions
• Communication skills - you can explain technical decisions clearly
• Team player - you're comfortable with code reviews and collaboration
• Growth mindset - you're eager to learn and improve continuously
• Performance-conscious - you understand GPU rendering and optimization techniques
• Creative technologist - you appreciate the intersection of code, art, and AI
• AI-curious - you're excited about working with cutting-edge AI models

Red Flags We Avoid

• Reliance on skipLibCheck or TypeScript workarounds
• Creating bandaid solutions instead of fixing root causes
• Ignoring architectural guidelines and patterns
• Poor testing practices or skipping tests
• Inability to work with existing codebases
• Direct coupling to infrastructure (e.g., direct Prisma in business logic)

Our Development Philosophy

We follow strict principles to ensure long-term maintainability:

1. Convention over Configuration - extend existing patterns, don't create new ones
2. DRY Principles - 2+ uses = shared package (packages/)
3. Schema-First - centralized Zod schemas with branded types in //genieartinc/schemas
4. Port-Adapter Pattern - technology-agnostic business logic via interfaces
5. Queue-First - all async work goes through BullMQ
6. No Relative Test Imports - tests must mirror real app imports
7. ENV_KEYS System - centralized configuration, no .env files ever
8. Repository Pattern - DatabaseFactory + Repository Adapters, never direct ORM in business logic
9. GPU-First Rendering - WebGPU with WebGL fallback for canvas performance

Performance Targets: API < 200ms | AI < 30s | Page load < 3s | 5xx < 0.1%

Development Workflow

• Enhanced GitHub Flow: main (production) ← staging ← feature/* branches
• CI/CD: GitHub Actions + Vercel preview deployments for every PR
• Code reviews are mandatory
• Automated checks: TypeScript, ESLint, architecture validation, tests
• Architecture validation runs on every PR (pnpm arch:validate)
• Serial builds with Turborepo (concurrency: 1) for architecture stability
• We value correctness over speed - proper solutions, not shortcuts

What We Offer

• Competitive salary + equity/stock options
• Remote-friendly
• Work on cutting-edge AI/creative tools
• Direct impact on product development
• Collaborate with creative technologists and AI researchers

How to Apply

Please submit:

1. Resume/CV
2. GitHub profile or portfolio with code samples
3. Cover letter addressing:
   • Why you're interested in Genie and this role
   • Your experience with similar architectures (hexagonal/clean architecture, monorepos, etc.)
   • Your background in creative coding and/or AI tools (if applicable)
   • A challenging technical problem you've solved and your approach
   • Any experience with WebGL/WebGPU, shaders, or generative art
4. Portfolio/demos showcasing:
   • Similar Industry project portfolio is must
   • Creative coding projects (p5.js, Three.js, shaders, etc.)
   • WebGL/WebGPU experiments or interactive graphics
   • AI integration projects (ComfyUI workflows, Stable Diffusion, etc.)
   • Canvas-based applications or visual tools
5. Code samples demonstrating:
   • Clean architecture/SOLID principles
   • TypeScript expertise (strict mode, advanced types, branded types)
   • Fullstack capabilities (frontend + backend)
   • Performance optimization or GPU programming