Senior Full Stack Developer (React, Node)

Cognito is a fast-moving, AI-driven EdTech platform that helps students engage with high-quality learning content. Over 1 million students and 35,000 teachers use our platform, completing more than 500 million practice questions, with our content reaching millions more through 130 million YouTube views.

Our platform is built using the MERN stack and hosted on AWS (S3, CloudFront, Elastic Beanstalk, CodePipeline) with MongoDB Atlas.

We are expanding our team to include a talented Full Stack Developer who will work on a mix of production-level features, proof-of-concept projects, and AI-driven solutions. You'll join our focused product team of three developers, a designer, and our CEO who acts as Product Manager

(You can explore our website here: www.cognito.org.)

The role

In this role, you will be enhancing and expanding our learning platform. While your focus will primarily be full stack development on the MERN stack, your interest in artificial intelligence will help us build dynamic, smart features that cater to the needs of students worldwide.

Responsibilities:

• Developing new product features and enhancements using ReactJS, GraphQL and MongoDB.
• Designing and implementing our extensive AI roadmap.
• Participating in code reviews, troubleshooting bugs, and planning development tasks.
• Contributing ideas to improve code quality, team practices, and development workflows.
• Supporting deployments to AWS.

Requirements

We're looking for a developer with strong experience in the following:

• Full-Stack Development (MERN) – Proficient in MongoDB, Express.js, React, and Node.js, with hands-on experience building scalable applications.
• GraphQL (Apollo Server Client) – Experience designing and consuming GraphQL APIs for efficient data fetching.
• AWS (S3, CloudFront, Elastic Beanstalk, CodePipeline) – Familiarity with cloud infrastructure, deployments, and CI/CD workflows.
• MongoDB Atlas – Understanding of database management, indexing, and performance optimisation.
• Front-End Development – Strong React skills, with a focus on performance, state management, hooks and functional component-driven architecture.
• Version Control Collaboration – Comfortable using Git, GitHub, and participating in code reviews.
• Figma (for design inspection) – Ability to translate Figma designs into functional and visually accurate UI components.
• Remote Communication Collaboration – Strong written and verbal communication skills, essential for working in a fully remote environment.
• UK-Based – While we operate remotely, all employees are based in the UK.

Desirable Skills (Nice to Have)

While not required, experience with any of the following is a plus:

• AI Machine Learning Integration – Experience working with AI-driven features, such as prompt chaining, fine-tuning, retrieval-augmented generation (RAG), or vector databases.
• Proof-of-Concept Development – Ability to rapidly prototype and iterate on new features or experimental projects.
• Analytics Data Processing – Familiarity with tools like Google Analytics and BigQuery for tracking and analysing platform performance.
• Next.js SSR – Understanding of server-side rendering and static site generation to optimise web performance.
• Backend Performance Scaling – Experience with caching strategies, API optimisation, and server performance tuning.

Who We're Looking For

Beyond technical skills, we seek a developer who brings the adaptability and independent drive that startup success demands:

• Flexible Adaptable – Able to quickly switch between different projects and priorities.
• Autonomous Reliable – Can take ownership of tasks with minimal supervision.
• Great Communicator – Can articulate technical decisions clearly and provide feedback on processes.
• Strong Problem Solver – Enjoys tackling technical challenges and improving system efficiency.
• Quality-Focused – Writes clean, maintainable, and scalable code while also being comfortable with rapid iteration when needed.

Benefits

We believe in supporting our team members with meaningful benefits that enhance both their professional and personal lives:

• Flexible Remote Work – Full remote setup with core hours, allowing you to balance work and life effectively.
• Competitive Package – Attractive salary with regular reviews and performance-based increases.
• Modern Work Culture – No unnecessary meetings or bureaucracy, focused on getting things done.
• Generous Holiday – 25 days annual leave + bank holidays.

Application process

We've designed our hiring process to be thorough yet efficient, typically completed within 2-3 weeks:

1. Initial Application – Short form with focused questions about your experience and motivations.
2. Video Introduction – Brief recorded responses to help us get to know you better.
3. Technical Assessment – Practical coding exercise that reflects real-world scenarios.
4. Team Interviews – Two-stage interview process:
• Technical discussion with the development team
• Culture fit conversation with the wider team

We aim to provide detailed feedback at each stage and keep you informed throughout the process.