Senior Software Engineer

Wentao Lin

*********.**@*****.*** https://www.linkedin.com/in/wentao-lin-82167a10 Dublin, Ireland Summary

Full-stack developer with experience delivering robust, scalable web applications across the financial, telecom, and travel industries. Skilled in designing and implementing end-to-end solutions using modern JavaScript frameworks (React, Vue.js, Node.js), backend technologies (Python, Java, .NET), and relational/non-relational databases such as PostgreSQL and MongoDB. In the financial sector, contributed to the development of secure, compliant platforms supporting transactions and encrypted data flows. In telecom, built real-time customer interfaces and analytics tools optimized for performance and uptime. In the travel industry, engineered dynamic booking systems and integrated third-party APIs to streamline user experience. Strong understanding of DevOps practices, including containerization with Docker, CI/CD pipelines, and cloud deployment. Adept at working in agile teams and focused on writing clean, maintainable code. Experience

Senior Software Engineer Mastercard – Dublin, Ireland Aug 2024 - Present Python, FastAPI, Pytest, Jest, React.js, Next.js, TypeScript, PostgreSQL, AWS, Docker

• Built secure, scalable backend services using Python (FastAPI) and PostgreSQL, powering real-time transaction workflows and internal risk analytics systems handling millions in daily volume.

• Developed responsive Angular applications and internal React-based dashboards to support operations teams, enabling real-time visibility into data pipelines and service health.

• Containerized services with Docker and established GitHub Actions-based CI/CD pipelines, significantly reducing manual effort and achieving zero-downtime deployments across environments.

• Redesigned legacy modules into cloud-native microservices, improving maintainability and performance while reducing infrastructure costs through auto-scaling on AWS (ECS + Fargate).

• Enhanced observability across services by integrating Prometheus, CloudWatch, and Grafana, and built alerting pipelines to support proactive SRE response and SLA adherence.

• Implemented DevSecOps pipelines with secret scanning, dependency vulnerability detection (Snyk, Trivy), and policy-as-code (Open Policy Agent), ensuring Mastercard’s software delivery met strict PCI-DSS and internal audit standards.

• Led the delivery of 3 proof-of-concept applications, including a real-time trade reconciliation engine and automated compliance monitoring dashboard; 2 were greenlit for production by engineering leadership.

• Improved automated test coverage to over 90% using Pytest, Jest, and Playwright, increasing confidence in releases and reducing post-deployment bugs by over 40%.

• Mentored two interns through Mastercard’s engineering development program, assigning progressively challenging tasks aligned with their growth while maintaining delivery velocity.

• Collaborated with platform engineering and cost optimization teams to refactor infrastructure-as-code

(Terraform), reduce redundant cloud spend, and simplify vendor onboarding processes.

• Participated in cross-team architecture guilds, promoting engineering consistency and reusable patterns for multi- tenant service provisioning, API contract versioning, and secure identity propagation. Senior Software Engineer Fidelity Investments – Dublin, Ireland Oct 2020 – Aug 2024 Python, FastAPI, Django, React.js, Next.js, TypeScript, PostgreSQL, Prisma, AWS, Docker, Git

• Led full-stack development of customer-facing web applications using Python (FastAPI, Django), React, Next.js, and TypeScript, powering platforms for service, marketing, and regulatory communications.

• Architected and implemented microservices within a service-oriented ecosystem, ensuring high availability and modularity across distributed financial systems.

• Designed and optimized PostgreSQL data models to support complex workflows, real-time analytics, and seamless data integrity for multi-channel communications.

• Defined and executed robust testing strategies, leveraging BDD and automation to support CI/CD pipelines and uphold strict quality standards in a regulated environment.

• Built extensive unit, integration, and end-to-end tests, enabling confident deployments and reducing production incidents in mission-critical systems.

• Translated business requirements into detailed technical designs and documentation, aligning engineering efforts with regulatory and compliance constraints unique to the financial industry.

• Improved performance and reliability of existing services by identifying bottlenecks, refactoring legacy code, and optimizing data access patterns.

• Collaborated across cross-functional teams product owners, analysts, QA, and DevOps to deliver features on time in Agile (Scrum) environments.

• Supported multi-environment deployments, coordinated UAT cycles, and led post-release validations, ensuring seamless integration with enterprise systems.

• Authored technical documentation and knowledge-sharing guides across initiatives supporting wealth management, retirement, and brokerage platforms.

Senior Software Engineer Mastercard – Dublin, Ireland Jan 2019 – Oct 2020 Python, FastAPI, Django, React.js, Next.js, TypeScript, PostgreSQL

• Modernized a legacy analytics dashboard by refactoring the front end from AngularJS to React.js, significantly improving application speed, maintainability, and user experience across web platforms.

• Enhanced web accessibility and cross-browser compatibility, ensuring full compliance with WCAG 2.1 standards and enabling inclusive access for diverse global user bases.

• Architected and developed microservices and distributed backend components using modern service-oriented design patterns, supporting high-throughput transactional systems and real-time analytics.

• Engineered performant, data-rich UIs capable of rendering and filtering high-dimensional datasets on the fly, optimizing performance across multiple devices and network conditions.

• Designed and built RESTful APIs and reusable infrastructure components, enabling seamless integration across Mastercard's internal platforms and third-party services.

• Led the design and implementation of scalable systems, contributing to system architecture decisions and aligning with Mastercard's security, compliance, and global scalability requirements.

• Wrote clean, testable, and maintainable code, integrating automated unit and integration testing with CI/CD pipelines to streamline deployments and reduce production incidents.

• Conducted in-depth performance profiling and system tuning, improving load times and reducing latency for mission-critical services handling large volumes of real-time data.

• Mentored junior engineers, providing technical guidance, conducting code reviews, and fostering a culture of collaboration, continuous learning, and engineering excellence.

• Improved team efficiency by identifying and removing process bottlenecks, contributing to internal tooling, code reuse strategies, and best practice adoption across multiple product teams.

• Collaborated with cross-functional teams including product, design, QA, and DevOps to deliver high-impact features from concept through production.

• Actively contributed to Mastercard’s engineering guilds, promoting knowledge sharing, architectural consistency, and internal tooling reuse across departments.

Bachelor of Computer Science Griffith College Dublin Sep 2001 - July 2005

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