David James Mitten

Sainsburys is one of the largest supermarkets in the UK with a large tech department. Responsibilities: - Mentoring juniors - React and Next js work - Code reviews - Planning and project management for regular feature deployment

Antler digital is a startup that helps companies build digital products. Responsibilities: - Expanded One Tribe's development capabilities through Antler Digital partnership, complementing primary role by contributing to diverse client projects in parallel. - Worked with MetaMask and Web3.js for blockchain integration for an NFT platform. - Created systems with Payload CMS, ensuring a flexible and scalable content management system. - Used github actions CI/CD for deployment locally and in production, ensuring a fast and reliable deployment process minimising human error. - Created unit tests with Jest, ensuring a comprehensive and reliable testing strategy, wherever we had budget to do so.

One Tribe is a carbon credit platform that allows users to track and offset their carbon footprint. Responsibilities: - Built custom BigCommerce application and engineered multi-platform webhook system integrating Magento, WooCommerce, BigCommerce, Shopify, Mailchimp, Gravity forms, etc. and marketing tools, processing thousands of daily events - Contributed to fullstack applications using React, Next.js, and Node.js with TypeScript, supporting 100+ active users - Collaborated with CTO to implement carbon milestone tracking system, managing environmental impact data for enterprise clients - Supported UI modernization by implementing Tailwind CSS, reducing stylesheet size by more than 40%, and accelerating component development - Developed custom Stripe payment processing handling $100K+ in revenue across multiple pricing tiers and products - Assisted with the internal Next.js admin dashboard replacing Retool, reducing customer support response time, and saving a minimum of 15+ engineering hours weekly - Establish CI/CD pipeline with GitHub Actions and Vercel, reducing deployment time - Contributed to testing suite development achieving 75% coverage on critical paths Implemented SSR-generated carbon impact pages for 100+ brands, improving load times and SEO considerably - Participated in code reviews and supported junior developers while maintaining quality standards - Simplified onboarding process, significantly decreasing user drop-off rates - Assisted in migration of 3GB of optimized text-based data from Firebase to Xata with zero downtime, improving query performance and handling 90,000+ cloud function invocations monthly