Senior Fullstack Engineer – (Remote, SaaS + AI)

Role Overview We’re looking for a Senior Fullstack Engineer to join our remote-first, Series A SaaS startup building a marketing automation platform for banks and credit unions. This is a high-impact role for an experienced engineer who thrives in fullstack environments and enjoys guiding architecture, mentoring peers, and taking ownership of systems across frontend, backend, and infrastructure.

You’ll be expected to demonstrate how you use AI tools (e.g., GitHub Copilot, ChatGPT, Code Interpreter, etc.) to accelerate your development workflow, improve code quality, and deliver faster. Additionally, you should have experience building — or contributing to — production-ready features that leverage AI functionality, such as LLM integration, intelligent automation, or personalised user experiences powered by machine learning.

Key Responsibilities

AI Acceleration & Product Integration

• Proactively use AI tools to boost productivity, debug faster, and generate high-quality code

• Identify opportunities to integrate AI capabilities into the product to enhance customer value

• Design and deliver features using AI/ML tools (e.g., OpenAI APIs, vector databases, LLM agents)

• Stay informed on emerging AI tech trends and champion practical use in engineering processes

Frontend Development

• Build and maintain modern web applications using React, TypeScript, and JavaScript

• Ensure code quality, reusability, and maintainability across multiple frontend repositories

• Implement clean architecture and UI patterns aligned with industry best practices

Backend & Integrations

• Develop and maintain backend services (Node.js, Ruby) with reliable integrations to external systems

• Maintain services responsible for third-party data synchronisation, storage, and communication

• Ensure scalability and performance across backend modules and APIs

Microservices Architecture & Infrastructure

• Contribute to the transition from a monolithic codebase to a microservices-based architecture

• Define service boundaries, design communication protocols, and select appropriate technologiesDesign and deploy infrastructure using AWS services (Lambda, DynamoDB, S3, Route53) and SST framework

• Optimise performance, monitor systems, and ensure high availability

Technical Leadership & Mentorship

• Review code and provide constructive, empathetic feedback via pull requests

• Mentor teammates, guide architectural decisions, and support problem-solving efforts

• Lead sprint planning, prioritise engineering work, and help remove technical blockers

• Break down large features into well-defined tickets and technical documentation

Compliance & Security

• Apply secure development practices aligned with the needs of fintech and martech environments

• Ensure data protection and access control measures are in place across services and integrations

• Collaborate with stakeholders to meet customer and industry compliance expectations

Required Qualifications

• 6+ years of software engineering experience with strong fullstack expertise

• Demonstrated use of AI tools (e.g., Copilot, ChatGPT, Claude, Codeium) to improve development speed and quality

• Experience building or contributing to customer-facing features powered by AI or LLMs

• Expert-level experience with React, TypeScript, JavaScript, Node.js

• Proficient in backend languages such as Ruby or JavaScript-based frameworks

• Experience working with AWS (especially Lambda, DynamoDB, S3) and infrastructure-as-code tools

• Comfortable contributing to architecture, planning, and cross-team collaboration

• Strong written and verbal communication skills

Preferred Qualifications

• Experience integrating AI APIs or ML models into production applications

• Familiarity with the SST framework for managing serverless appsExperience in fintech, martech, or regulated industries

• Experience mentoring engineers or providing technical leadership in distributed teams

Awareness of compliance and data protection standards relevant to financial institutions