Lead Software Engineer — Connectivity

Mastercard Inc.; Warszawa; On-site; PLN 300,000 - 520,000; Full time

Job summary

Mastercard Inc. in Warsaw seeks a Lead Software Engineer for connectivity across Europe. You will own end-to-end development of scalable API links to financial institutions, guiding design choices and delivering reliable services in production.

You will mentor engineers, collaborate with Product, Architecture, Security, and SRE teams, and drive automation and testing strategies to ensure high availability and security in Open Banking environments.

Qualifications

• 8–10 years of professional software engineering experience
• Strong hands-on experience building cloud-based, highly available systems
• Deep expertise in backend engineering (API design, reliability, production support)
• Proven ability to solve complex technical problems and influence design decisions
• Experience delivering and operating end-to-end systems in production environments
• Strong collaboration skills with Product and business stakeholders
• Familiarity with banking/payments/open banking (PSD2) environments
• Strong communication and problem-solving skills

Responsibilities

• Own end-to-end delivery of engineering solutions—from design through development, deployment, and production support
• Solve complex technical problems and drive system design decisions
• Design, build, and operate scalable APIs and backend services
• Review code and uphold high standards of quality, performance, and maintainability
• Apply best practices across SDLC, testing, security, and observability
• Collaborate with Product, Architecture, Security, and SRE teams
• Implement robust testing strategies (unit, integration, end-to-end)
• Drive automation and improvements in developer productivity and operational efficiency
• Mentor engineers and support them in solving technical challenges and growing their skills

Skills

Backend engineering

API design

Cloud-based systems

Production support

Collaboration with product

PSD2/open banking knowledge

Tools

Azure

AWS

PostgreSQL

Flyway

GitHub Copilot

Job description

Title and Summary Lead Software Engineer — Connectivity Overview

Our Purpose Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we’re helping build a sustainable economy where everyone can prosper. We support a wide range of digital payments choices, making transactions secure, simple, smart and accessible. Our technology and innovation, partnerships and networks combine to deliver a unique set of products and services that help people, businesses and governments realize their greatest potential.

This role sits within Mastercard’s Open Finance Europe – Connectivity team, building and operating scalable API connectivity to financial institutions across Europe. As a Lead Software Engineer, you will own end-to-end delivery of secure, reliable connectivity services. This is a hands-on role focused on solving complex problems, driving technical decisions, and delivering high-quality systems from design through production. You will partner with Product and business stakeholders to deliver new capabilities, improve platform reliability, and scale integrations across markets.

Core Responsibilities

• Own end-to-end delivery of engineering solutions—from design through development, deployment, and production support
• Solve complex technical problems and drive system design decisions
• Design, build, and operate scalable APIs and backend services
• Review code and uphold high standards of quality, performance, and maintainability
• Apply best practices across SDLC, testing, security, and observability
• Collaborate with Product, Architecture, Security, and SRE teams
• Implement robust testing strategies (unit, integration, end-to-end)
• Drive automation and improvements in developer productivity and operational efficiency
• Mentor engineers and support them in solving technical challenges and growing their skills

Technology Stack

• C#, .NET 10, Web APIs
• Java/Spring Boot (plus)
• Azure (App Services, Blob Storage, KeyVault, CI/CD)
• AWS (Microservices, S3, Redis, CI/CD pipelines)
• PostgreSQL, Flyway
• Generative AI tools (GitHub Copilot, etc.)

All About You Must Have

• 8–10 years of professional software engineering experience
• Strong hands-on experience building cloud-based, highly available systems
• Deep expertise in backend engineering (API design, reliability, production support)
• Proven ability to solve complex technical problems and influence design decisions
• Experience delivering and operating end-to-end systems in production environments
• Strong collaboration skills with Product and business stakeholders
• Familiarity with banking/payments/open banking (PSD2) environments
• Strong communication and problem-solving skills

Nice to Have

• Experience with Open Banking or bank connectivity at scale
• Experience with AI-assisted engineering tools (Copilot, etc.)
• Track record of improving efficiency through automation
• Familiarity with infrastructure-as-code and platform governance

Corporate Security Responsibility

All activities involving access to Mastercard assets, information, and networks comes with an inherent risk to the organization and, therefore, it is expected that every person working for, or on behalf of, Mastercard is responsible for information security and must: Abide by Mastercard’s security policies and practices; Ensure the confidentiality and integrity of the information being accessed; Report any suspected information security violation or breach, and Complete all periodic mandatory security trainings in accordance with Mastercard’s guidelines.

Everyone wants easier ways to pay; we invent them. Checkout lines are slow; we speed them along. Merchants want more sales; we give them data and insights. People need financial access; we connect them. Corporate purchasing is complicated; we make it simple. Commuters are busy; we speed them on their way. Governments need greater efficiencies; we help create them. Small businesses are virtual; we give them access to a world of buyers. Retailers want to fight fraud; we provide the tools.