LongDo
preferred name “Leo”
Building production-grade web applications at scale. 10+ years crafting React ecosystems at Amazon, Google, and beyond.
Engineering at scale,
with care for detail.
Senior Backend Engineer with 10+ years of experience across Cisco, Google, and Amazon. Expert in C#, Python, and Cloud AI/ML infrastructure with a strong focus on scalable microservices, distributed systems, and GDPR-compliant data handling.
Technical Expertise
Languages
Cloud & Infrastructure
AI / ML
Databases & Messaging
Observability & Tooling
Practices
Work Journey
Amazon
Software Development Engineer
Built and deployed .NET-based backend services for Alexa Voice Commerce and the AWS Lambda control plane, reducing voice-to-purchase latency, enabling zero-downtime migrations, and mentoring four engineers to promotion.
Senior Software Engineer
Maintained core backend services for Google Calendar (500M+ monthly active users) and YouTube, while contributing C#/.NET tooling and model-serving infrastructure to Google Cloud AI.
Cisco
Software Engineer
Built the DevNet Developer Platform from scratch — launching with 10k+ registered developers — and maintained CloudCenter's cost reporting pipelines using C# and AWS SDK.
Academic Background
BSc in Computer Science
University College Cork (UCC)
Let's build something great together.
I'm open to new opportunities, collaborations, and interesting conversations. Drop me a message and I'll get back to you promptly.