At Scalapay, we’re shaping a culture with high standards, independent and critical thought, innovation, ownership, and continuous learning. We operate in a fast-moving, tech-driven environment, and we’re looking for people who thrive in change, think boldly, and take initiative.

If you’re ready to put your potential to the test in a hiring process designed to spotlight exceptional talent, this is your chance to stand out and grow with one of Europe’s most ambitious fintech teams.

#MakeItHappen #PlayAsATeam #StayCurious #FocusOnCustomer.

The Mission

Scalapay is an AI-first international fintech. We're looking for a Backend Software Engineer with banking platform experience to join our Consumer Banking team. You'll design and deliver high-performance, secure and scalable APIs that power our customer experience. You'll work spec-first: you define what good looks like, and AI coding agents help you build it faster without lowering the bar on quality, security or compliance.

Key Responsibilities

AI-First Engineering

- Write clear specifications and technical designs that AI coding agents (e.g.

Claude

Code) implement from, then direct, review and test their output;

- Take full ownership of AI-generated code, making sure it meets our standards for security, performance and PCI DSS compliance before it ships;

- Use AI across the whole development lifecycle: test generation, code review, documentation, debugging and incident analysis;

- Help shape the team's AI tooling, shared context, prompts and guardrails so that development becomes more automated over time.

API Development & Integration

- Design, build and maintain high-quality REST APIs using NestJS and TypeScript;

- Meet performance targets of under 200ms response time through caching, query optimisation, payload compression, rate limiting, pagination and filtering;

- Integrate with external services and banking partners, keeping the platform resilient to third-party failures.

Architecture

- Build scalable,



maintainable microservices using dependency injection, modular design and clean code principles;

- Develop event-driven systems and real-time features.

Security & Compliance

- Implement authentication and authorisation (JWT, OAuth2, MFA) and API security measures (TLS, API key management, request signing);

- Apply secure coding practices, including input validation and protection against SQL injection and XSS;

- Ensure PCI DSS compliance and encryption of sensitive data at rest and in transit.

Data & Infrastructure

- Design efficient MySQL/PostgreSQL schemas, manage migrations and optimise queries and indexing;

- Deploy on AWS with Docker, EKS, and CI/CD pipelines, working with DevOps on infrastructure requirements;

- Monitor system performance through logging, tracing and alerting.

Required Qualifications

- 5 years of backend development experience, including banking platforms, system integrations and ledgers

- 3 years with NestJS and TypeScript, or comparable frameworks and languages

- Proven AI spec-driven development: you've shipped production software by specifying, directing and validating the work of AI coding agents

- Strong MySQL and/or PostgreSQL skills: schema design, query optimisation and indexing

- Deep knowledge of REST API design, plus GraphQL experience (code-first and schema-first)

- Track record of finding and fixing API performance bottlenecks, including caching (Redis, Memcached, HTTP caching)

- Strong API security background: authentication, authorisation, encryption, security testing and vulnerability assessment

- Experience with AWS (EC2, RDS, Lambda,



API Gateway, CloudWatch) or a comparable cloud platform

- Solid testing practice (Jest, unit and integration testing), Git workflows and agile delivery

What We're Looking For

- Banking platform experience. You’ve built or worked on banking systems, including system integrations and ledgers.

- An AI-first builder. You can show us AI projects that demonstrate your spec-driven way of working, and you have good judgement about when to trust AI output and when to challenge it.

- An owner. You think about performance, scalability and security by default, not as an afterthought.

- A collaborator. You're comfortable with code reviews and enjoy sharing what you learn, including the AI workflows that work for you.

- A continuous learner. You keep up with backend, security and AI-assisted engineering practices.

Why Join Scalapay

- Attractive packages based on skills and experience, the salary band we have for this position is of EUR 65'000 - 80'000 (Gross Annual Salary);

- An international fintech with an AI-first approach, raising the bar daily on how we build software and solve complex problems

- Work alongside industry tech leaders focused on exceptional user experiences

- Personalised support to grow your career and take ownership of the products you deliver

- Modern technology and the freedom to bring your own flair

Recruitment Process

- A quick chat with one of our Talent Acquisition team members
- The first interview with the Hiring Manager to dive deep into your experiences and better understand your motivation
- A case study to test your hard skills
- A final chat with Simone, our CEO

Want to learn more? Don't hesitate to explore our Careers website, our LinkedIn and Glassdoor pages.

Pro tip: send your CV in English ?

Super Pro tip: we know that application processes can be scary and frustrating but… we look for talent, not people that tick all our boxes.

📌 Senior Backend Software Engineer - Consumer Banking (Milano)
🏢 Scalapay
📍 Milano