Backend Software Engineer

Published: 2025-12-23

Scalapay is the fastest growing European fintech transforming the way people manage their money. Founded in 2019, we pioneered the Buy Now Pay Later model in Southern Europe and Central Europe and now serve over 9 million customers and 10,000+ merchant partners. Backed by leading global investors like Tiger Global, Tencent and top-tier strategic partners like Poste Italiane, we’re scaling ...

Job details

Milan, Italy (city)
On-site
Full-time

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

We're seeking a skilled Backend Software Engineer to join our Experiences team at Scalapay. You'll be responsible for building and maintaining high-performance, scalable REST APIs that power our user experience. This role focuses on delivering exceptional user experiences through robust backend architecture and optimized API performance.

Key Responsibilities:

API Development & Performance

  • Design, build, and maintain high-quality REST APIs using NestJS framework
  • Optimize API performance through caching strategies, query optimization, and payload compression
  • Implement rate limiting, pagination, and filtering for scalable data handling
  • Ensure APIs meet performance benchmarks with sub-200ms response times

Security & Compliance

  • Implement robust authentication and authorization systems (JWT, OAuth2, multi-factor authentication)
  • Apply security best practices including input validation, SQL injection prevention, and XSS protection
  • Ensure PCI DSS compliance for payment processing and sensitive data handling
  • Implement API security measures including HTTPS/TLS, API key management, and request signing
  • Design secure data encryption at rest and in transit

Backend Architecture

  • Develop scalable, maintainable backend services using NestJS with TypeScript Design and implement microservices architecture patterns
  • Apply dependency injection, modular architecture, and clean code principles
  • Build event-driven systems and real-time features using WebSockets

Database & Cloud Infrastructure

  • Work with MySQL databases, optimizing queries and implementing proper indexing
  • Design efficient database schemas and manage migrations
  • Deploy and manage applications on AWS infrastructure
  • Implement containerization with Docker and CI/CD pipelines
  • Monitor system performance and implement logging/tracing solutions
Required Qualifications:

Technical Skills

  • 5+ years of backend development experience
  • 3+ years hands-on experience with NestJS and TypeScript/JavaScript
  • Strong proficiency in MySQL database design, optimization, and query performance
  • Extensive experience with AWS services (EC2, RDS, Lambda, API Gateway, CloudWatch)
  • Proven expertise in GraphQL API development (both code-first and schema-first approaches)
  • Deep understanding of REST API design principles and best practices

Performance & Security Focus

  • Demonstrated experience in API performance optimization and bottleneck identification
  • Knowledge of caching strategies (Redis, Memcached, HTTP caching)
  • Experience with database query optimization and indexing strategies
  • Strong background in API security including authentication, authorization, and data protection
Development Practices
  • Experience with Git version control and collaborative development workflows
  • Knowledge of testing frameworks (Jest, unit testing, integration testing)
  • Advanced understanding of security best practices (JWT, OAuth2, data encryption, secure coding)
  • Experience with security testing and vulnerability assessments
  • Experience with agile development methodologies
What We're Looking For:
  • Performance-minded developer who naturally thinks about optimization and scalability
  • Security-conscious professional who prioritizes secure coding practices and compliance
  • Strong problem-solver who can identify and resolve API bottlenecks and security vulnerabilities
  • Collaborative team player comfortable with code reviews and knowledge sharing
  • Detail-oriented professional who values code quality, maintainability, and security
  • Continuous learner who stays current with backend development and security best practices
Why you should join Scalapay:
  • International environment with significant challenges to be met every day
  • Lots of opportunities to work with a team of industry tech leaders who are focused on delivering products that offer exceptional user experiences
  • Personalised support to accelerate your professional growth and take ownership of the products you deliver: we want to help you grow!
  • Latest technologies and being encouraged to bring your flair to the role.
Recruitment Process:
  1. A quick chat with one of our Talent Acquisition team members
  2. The first interview with the Hiring Manager to dive deep into your experiences and better understand your motivation
  3. A case study to test your hard skills
  4. 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.

We believe in the power of diversity: Scalapay is an Equal Opportunity Employer for any minority, disability, gender identity or sexual orientation.

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