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