Senior Full Stack Engineer - Nodejs & React - london

Senior Software Engineer – Full Stack (Cybersecurity SaaS)

We are seeking experienced Senior Full‑Stack Software Engineers to join our growing engineering team and help build secure, scalable, and customer‑centric SaaS products serving both B2B and B2C markets. This role offers the opportunity to work on cutting‑edge cybersecurity solutions that protect millions of consumers and small businesses.

Key Responsibilities

• Design, develop, and deliver new features for cybersecurity SaaS platforms.
• Collaborate closely with Product Managers, UX Designers, and Engineering teams to define technical requirements and implementation plans.
• Estimate development effort and proactively identify risks, blockers, and dependencies.
• Contribute to continuous improvement of engineering practices, processes, and team culture.
• Research, prototype, and evaluate Generative AI and Large Language Model (LLM) capabilities to drive product innovation.

Full‑Stack Development

• Develop clean, maintainable, scalable, and well‑tested software solutions.
• Build responsive and reusable frontend applications using React and TypeScript.
• Develop RESTful APIs and backend services using NestJS and Node.js.
• Implement software security best practices across application layers.
• Participate in code reviews and contribute to engineering standards and best practices.
• Develop reusable components, libraries, and shared services.
• Integrate third‑party APIs and intelligent services into product solutions.
• Utilize modern development tools and AI‑assisted engineering platforms to improve productivity and code quality.

Solution Design & Architecture

• Design scalable API architectures, schemas, and technical documentation.
• Develop reusable frontend component architectures and design systems.
• Make sound architectural decisions focused on scalability, maintainability, security, and customer experience.
• Design microservices‑based solutions and distributed systems.
• Evaluate and optimize system performance, reliability, and scalability.
• Design and implement AI‑enhanced solutions leveraging Model Context Protocol (MCP), Retrieval‑Augmented Generation (RAG), and vector databases such as Pinecone and Weaviate.

Testing & Quality Assurance

• Develop and maintain comprehensive unit and integration tests.
• Ensure software quality through automated testing and peer reviews.
• Follow test‑driven and quality‑focused development practices.

Maintenance & Production Support

• Troubleshoot, debug, and resolve software defects and performance issues.
• Address application security vulnerabilities and operational incidents.
• Support production environments and participate in on‑call rotations when required.
• Continuously enhance existing products and services.

Required Qualifications

• Bachelor's degree in Computer Science, Software Engineering, or equivalent practical experience.
• 5+ years of professional software development experience.
• Strong proficiency in JavaScript, TypeScript, HTML, and CSS.
• Hands‑on experience building modern web applications using React.
• Strong experience developing RESTful APIs using NestJS and Node.js.
• Experience designing and implementing microservices architectures.
• Understanding of application security, cloud security, and networking fundamentals.
• Strong knowledge of software engineering principles, data structures, algorithms, and system design.
• Experience with Git and modern version control practices.
• Understanding of Agile development methodologies and DevOps practices.
• Excellent analytical, troubleshooting, and problem‑solving skills.
• Solid verbal and written communication skills.
• Professional English proficiency with the ability to collaborate effectively with US‑based stakeholders via Slack, Azure DevOps, and video conferencing.

Preferred Qualifications

• Experience with unit testing frameworks such as Jest, Mocha, and similar testing frameworks.
• Experience with SaaS platform architecture and multi‑tenant systems.
• Exposure to cloud platforms including Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP).
• Understanding of cloud‑native application development and deployment.
• Experience with developer productivity tools and AI‑assisted coding platforms.
• Experience designing and implementing AI‑powered applications.
• Knowledge of Model Context Protocol (MCP), Retrieval‑Augmented Generation (RAG), vector databases (Pinecone, Weaviate, etc.), LLM integrations and AI orchestration framework.

Desired Skills

• Full‑Stack Development (React, TypeScript, NestJS, Node.js)
• REST API & Microservices Architecture
• Cloud Security
• SaaS Platform
• AI/LLM Integration
• MCP & RAG
• AWS / Azure / GCP
• Agile & DevOps
• Unit Testing
• System Design
• Cybersecurity Application