Full Stack Engineer (Next.js / Three.js)

Angry Swan Labs; Remote; GBP 80,000 - 100,000; Part time

Job summary

A leading tech consultancy is seeking a Freelance Full-Stack Engineer (React / 3D) for a temporary project in the UK. The successful candidate will develop a sophisticated browser-based 3D editor and build essential modules for media processing and device synchronization. Must possess expertise in React, 3D environments, and utilize AI tools effectively. This position allows for hybrid work for a duration of 4-6 weeks, emphasizing autonomy in delivering specialized technical solutions.

Qualifications

• Proficient in building complex 3D web applications.
• Experience with AI Coding Assistants for development efficiency.
• Ability to work autonomously and manage complex technical requirements.

Responsibilities

• Architect the core web infrastructure for a SaaS platform.
• Develop a browser-based editor for 3D asset manipulation.
• Implement client-side media processing solutions.

Skills

React

WebGL

TypeScript

Three.js

AI tools

Tools

WASM

FFmpeg.wasm

Tailwind CSS

Job description

Freelance Full-Stack Engineer (React / 3D)

Role: Full-Stack Developer (Next.js / WebGL)

Engagement Type: B2B Contract / Freelance (Project-Based)

Location: Remote (UK-based only)

Duration: Estimated 4-6 Weeks (Fixed Deliverables)

1. The Engagement

We are seeking a high-velocity freelance engineer to architect the core web infrastructure for a SaaS platform. The project involves building a sophisticated browser-based editor that handles 3D asset manipulation, complex state management, and client-side media processing.

Operational Model: This is a hybrid-workflow project. The contractor is explicitly encouraged to utilise AI Coding Assistants (Cursor, Copilot, etc.) to handle boilerplate and UI velocity, focusing their manual engineering effort on the complex WebGL architecture and state logic.

2. Statement of Work

The project requires the delivery of four core technical modules:

A. The 3D Editor Environment

• Requirement: Build a performant editor using React Three Fiber (R3F).
• Functionality: Implementation of a workspace allowing for the import, arrangement, and manipulation of 3D assets (.glb) using standard transform controls.
• Key Challenge: Efficiently managing scene graphs and transient updates outside the React render loop to maintain performance.

B. Browser-Based Media Generation

• Requirement: Architect a client-side pipeline to process and export canvas content.
• Functionality: The system must be able to capture frame-data from the 3D context and assemble it into media files entirely within the browser, minimizing server-side dependencies.
• Tech: Proficiency with WASM-based solutions (e.g., FFmpeg.wasm) is required.

C. Real-Time Device Synchronization

• Requirement: Create a low-latency "Handshake" and data layer between the web session and external connected clients.
• Functionality: Implement a secure pairing flow (e.g., code-based) that facilitates the bi-directional sync of JSON state data between the web app and remote sessions.

D. Interactive 2D Overlay

• Requirement: A manipulation layer for defining regions of interest.
• Functionality: Implementation of a vector-based drawing interface (using libraries like fabric.js) to generate coordinate data and masks for backend processing.

3. Tech Stack

• Frontend: Next.js 14+ (App Router), TypeScript, Tailwind CSS.
• 3D Environment: Three.js ecosystem (React Three Fiber, Drei).
• State Management: Zustand (Crucial for the 3D/UI bridge).
• Backend Infrastructure: Supabase (PostgreSQL, Auth, Storage).
• Media Processing: Browser-based encoding (WASM).

4. Contractor Profile

We are looking for a specialist who:

• Is an "AI-Native" Developer: You move faster than the average dev because you leverage AI tools to automate the mundane, allowing you to ship complex features rapidly.
• Understands 3D on the Web: You know the difference between a mesh and a geometry, you understand scene graphs, and you know how to optimize assets for browser memory limits.
• Delivers Autonomous Solutions: You can take a technical requirement and execute it end‑to‑end without daily micro‑management.

5. Timeline

• Phase 1: Core Chassis, Auth, and Asset Import.
• Phase 2: State Management & Sync Logic.
• Phase 3: Client‑Side Rendering Pipeline.
• Phase 4: API Integration & UI Polish.