Open to networking

Hello, I'mZsolt Kalman

Senior Software Engineer

Backend & Full-Stack specialist with 5+ years experience building scalable, secure solutions. Expert in Node.js, NestJS, .NET Core, and Microservices. Passionate Security Champion.

5+Years Experience
Security Champion
Architecture Driven
Zsolt Kalman
Node.js
.NET
Security
NestJS
Clean Architecture
TDD
DDD

Professional Experience

Instructure

Senior Software Engineer Sep 2024 - Present · Remote

Driving backend architecture and scalability for Instructure's Portfolio tool. Led the transition from MongoDB to PostgreSQL and implemented Hexagonal Architecture.

  • System Architecture: Redesigned the backend to use Ports and Adapters, enabling a seamless database swap and faster feature development
  • Scalability: Built a Redis-backed job queue (BullMQ) that cut heavy processing tasks from 30s to sub-second async acknowledgments
  • Security & Scale: Engineered multi-region LTI routing for data residency compliance and fixed critical data isolation vulnerabilities
Node.jsNestJSPostgreSQLRedisKubernetes

Taxually

Senior Software Engineer Aug 2024 - Sep 2024

Contributed to cutting-edge tax automation platform during intensive project engagement.

.NET CoreMicroservices

Asura Technologies Ltd.

Senior Software Engineer Dec 2023 - Aug 2024 · Hybrid

Developed intelligent traffic solutions deployed primarily across the United States.

Backend DevelopmentIoTTraffic Systems

Spark Consulting

Full Stack Engineer Sep 2019 - Dec 2020 · Part-time

Delivered end-to-end solutions for multiple greenfield projects, from planning to deployment.

BlazorAngular.NET CoreAzure DevOps

Avatao

Content Developer Apr 2018 - Aug 2019 · Part-time

Created high-quality hands-on technical tutorials for a cybersecurity training platform.

  • Security Education: Developed engaging content for Node.js and .NET learning paths focusing on secure coding practices
  • Infrastructure: Utilized Docker to create containerized environments and Python 3 for automation
SecurityDockerPythonNode.js

BotCool

NodeJS Developer Intern May 2017 - Sep 2017 · Part-time

Gained foundational professional experience building chatbots for Facebook Messenger using Node.js and Azure.

Node.jsAzureChatbots

Technical Skills

Backend

C# / .NET Core
ASP.NET Core
Node.js
NestJS

Databases & ORMs

PostgreSQL
Entity Framework
Redis
Prisma ORM
MongoDB

Architecture

Microservices
Hexagonal Architecture
Event-Driven
API Design

DevOps

Kubernetes
Docker
AWS
Terraform / Helm

Security

Security Best Practices
Vulnerability Assessment

AI & Applied LLMs

Agentic Coding
LLM Integration
Claude / Gemini

Frontend & Tools

React / TypeScript
Angular / Blazor
Git / GitHub
Sentry / Monitoring

Engineering Philosophy

Security-First Mindset

Served as Security Champion at LastPass, integrating security practices into every stage of development

Test-Driven Quality

Comprehensive testing and idempotency guarantees ensure reliable, predictable systems

Clean Architecture

Hexagonal Architecture adoption enabled seamless database migrations without touching business logic

Documentation & Clarity

RFCs, architectural decision records, and clear code comments for maintainable codebases

Performance-Conscious

Proactive optimization through caching strategies, query analysis, and async processing

Collaborative Approach

Code reviews focused on mentoring, knowledge sharing, and building team capabilities

Personal Projects

MediaMerit

A personal project showcasing full-stack development capabilities with modern web technologies.

Full-StackWeb Development

Education

Budapest University of Technology and Economics

Bachelor's Degree in Computer Science

2017 - 2021

Let's Work Together

Based in Budapest, Hungary

Open to remote opportunities worldwide