Domagoj Korman, Developer in Zagreb, Croatia
Domagoj is available for hire
Hire Domagoj

Domagoj Korman

Bio

Domagoj is a senior full-stack engineer with 10+ years of experience building scalable systems, complex workflows, and resilient integrations across fintech, telecom, public transit, and product environments. He focuses on pragmatic architecture, reliable back-end systems, and polished user experiences. He combines strong system design with hands-on delivery across the front and back ends.

Portfolio

SandboxAQ
JavaScript, TypeScript, React, Python, Go, Kotlin, GraphQL, REST, Flask, Redis...
Toptal
Electron, React, TypeScript, JavaScript, GraphQL, Webpack, HTML5, CSS, Jest...
The Productive
JavaScript, CSS, HTML, Ember.js, Technical Leadership, Team Mentoring...

Experience

  • Git - 12 years
  • Docker - 8 years
  • Technical Leadership - 8 years
  • React - 8 years
  • System Design - 8 years
  • TypeScript - 8 years
  • Full-stack - 5 years
  • Elixir - 4 years

Preferred Environment

MacOS, Visual Studio Code (VS Code), Docker, Git, PostgreSQL, TypeScript, React, JavaScript, Elixir, Phoenix

The most amazing...

...system I've built was a resilient integrations platform handling failures, retries, and async workloads at scale.

Work Experience

Senior Full-stack Engineer

2023 - 2026
SandboxAQ
  • Transitioned from the front end to full-stack engineering, taking ownership of back-end services and contributing to API delivery across a distributed system.
  • Designed and implemented a resilient integrations architecture for connecting external services (AWS, CrowdStrike, ServiceNow, Tanium, Venafi), supporting safe failure handling, retries, and rate limiting.
  • Re-architected synchronous processing workflows into chunked, parallel background jobs, significantly improving system throughput and scalability.
  • Built and maintained asynchronous processing pipelines using Redis Queue, Temporal, and Kafka for long-running distributed workloads.
  • Developed back-end services and API endpoints across Python (Flask), Go, and Kotlin microservices, contributing to system-wide performance and reliability improvements.
  • Optimized critical GraphQL queries by replacing inefficient ORM-generated SQL with targeted raw SQL, improving the performance of complex data operations.
  • Introduced and enforced front-end engineering standards, including TypeScript adoption, ESLint rollout, and structured code review practices across teams.
  • Led technical direction for integration architecture, defining patterns for adding new external services without destabilizing core system reliability.
  • Improved system reliability by introducing structured error handling patterns for third-party integrations, reducing cascading failures across dependent services.
Technologies: JavaScript, TypeScript, React, Python, Go, Kotlin, GraphQL, REST, Flask, Redis, Apache Kafka, Temporal, Kubernetes, Docker, Git, SQL, Microservices, CircleCI, GitHub Actions, Technical Leadership, Amazon Web Services (AWS), System Design, Third-party Integration, Bazel, PostgreSQL, Node.js, Full-stack, API Development, SaaS, REST APIs, Claude Code, GitHub, APIs, Tailwind CSS, API Integration, Real-time Data, Vite, Application Modernization

Senior Front-end Engineer

2022 - 2023
Toptal
  • Built and shipped core features for a client-facing Electron desktop application used by freelancers to access job opportunities and platform services.
  • Designed and implemented front-end architecture using TypeScript, Webpack, and component-driven structure to improve maintainability and scalability.
  • Integrated GraphQL-based back-end services, including authentication and notification systems, adding a local-first development and testing abstraction layer.
  • Established front-end engineering standards, including TypeScript patterns, ESLint rules, and shared conventions across the codebase.
  • Improved and stabilized a shared component library by resolving reusable component issues and fixing TypeScript typing inconsistencies across projects.
  • Increased product reliability by strengthening testing practices, improving CI workflows, and supporting end-to-end validation processes.
  • Collaborated in a cross-platform engineering team, resolving desktop-specific issues, including Windows environment debugging and performance tuning.
Technologies: Electron, React, TypeScript, JavaScript, GraphQL, Webpack, HTML5, CSS, Jest, CircleCI, Git, Component Libraries, Cross-platform App Development, ESLint

Senior Front-end Engineer

2020 - 2022
The Productive
  • Led incremental migration from JavaScript to TypeScript across a large legacy front end, improving maintainability and reducing regression risk during active development.
  • Refactored and modularized core application architecture, breaking down a monolithic front end into smaller, reusable modules.
  • Delivered key product features across billing, invoicing, and operations workflows used daily by a large customer base.
  • Mentored and supported a team of eight front-end engineers in adopting TypeScript and improving code quality practices.
  • Conducted code reviews and introduced consistent front-end engineering standards, improving long-term maintainability of the codebase.
  • Collaborated closely with product and back-end teams to deliver complex business features under tight delivery constraints.
Technologies: JavaScript, CSS, HTML, Ember.js, Technical Leadership, Team Mentoring, TypeScript, Ruby on Rails 5, PostgreSQL, Node.js, SaaS, Stripe, GitHub, APIs, Tailwind CSS, API Integration, PDF, Application Modernization

Front-end Engineer

2018 - 2020
Infinum
  • Built and delivered multiple client applications across education, fintech, telecom, and transportation domains, including real-time chat, location tracking, media capture, and video conferencing features.
  • Developed a cross-platform solution enabling web, iOS, and Android applications from a shared JavaScript codebase, used to ship more than 10 production applications.
  • Acted as technical lead on multiple projects, responsible for architecture decisions, technology selection, estimates, and client communication.
  • Contributed to building an education platform during the COVID-19 transition, enabling large-scale virtual conferencing capabilities for distributed users.
  • Mentored junior engineers through code reviews, technical guidance, and presentation preparation, supporting team onboarding and growth.
  • Improved team development practices and workflows by introducing standardization and incremental engineering process improvements.
Technologies: React, Angular, CSS, HTML, JavaScript, SemaphoreCI, TypeScript, Express.js, Next.js, NestJS, Node.js, Fintech, GitHub, Tailwind CSS, API Integration, React Native, PDF, Application Modernization

Android Engineer

2015 - 2018
Infinum
  • Built a real-time chat feature using WebSockets for banking applications used by large user bases across production environments.
  • Developed and maintained Goldfinger, an open-source Android library for fingerprint authentication, widely reused across projects and significantly reducing implementation time.
  • Designed the initial MVVM architecture for Android projects, which was later adopted as a team standard.
  • Mentored students at an Android academy, teaching practical Android development and production engineering practices.
  • Contributed to multiple Android applications across fintech and enterprise domains, focusing on performance, stability, and maintainability.
Technologies: Android, Kotlin, Java, Git, XML, Bitrise, CircleCI, Technical Leadership, Team Mentoring, Fintech, GitHub

Experience

AQtive Guard

https://www.aqtiveguard.com/
AQtive Guard is an enterprise security platform for managing and protecting AI systems and cryptographic infrastructure at scale. It provides centralized visibility across non-human identities, AI agents, and machine-to-machine services, along with full inventory and governance of cryptographic assets.

The platform integrates with major enterprise systems, including AWS, ServiceNow, CrowdStrike, and other infrastructure tools, to aggregate security signals and build a unified view of organizational risk. It enables the detection of vulnerabilities, misconfigurations, and suspicious activity across distributed environments.

AQtive Guard supports automated risk analysis, prioritization, and remediation workflows while enforcing security policies in real time through runtime guardrails. It is designed to help enterprises manage AI adoption safely, secure sensitive credentials, and prepare cryptographic systems for post-quantum requirements.

Productive

https://productive.io/
Productive is an agency management web application written in Ember.js with a mix of JavaScript and TypeScript. My biggest accomplishment on the project was migrating it from JavaScript to TypeScript. I also implemented numerous features on the project that improved the application's user experience.

Underline

https://underline.io/
An education application used to organize virtual conferences worldwide with thousands of users. I came to the project as a technical lead, so I was responsible for the tech stack, standardizing coding practices, giving estimates, and mentoring less experienced colleagues.

The most significant achievement I made on the project was when COVID-19 came, and I developed a Zoom-like feature on it to allow the client to have virtual conferences in less than two months.

Education

2015 - 2017

Master's Degree in Software Engineering

University of Zagreb, Faculty of Electrical Engineering and Computing - Zagreb, Croatia

2012 - 2015

Bachelor's Degree in Software Engineering

University of Zagreb, Faculty of Electrical Engineering and Computing - Zagreb, Croatia

Skills

Libraries/APIs

React, Node.js, API Development, REST APIs, Stripe

Tools

SemaphoreCI, Git, CircleCI, Webpack, GitHub, TokBox, Jenkins, Bazel, Claude Code

Languages

JavaScript, CSS, HTML, TypeScript, Kotlin, Java, XML, GraphQL, HTML5, SQL, Elixir, Python, Go

Frameworks

Ember.js, Angular, Jest, Flask, Phoenix, Express.js, Next.js, NestJS, Tailwind CSS, Ruby on Rails 5, Electron, React Native

Paradigms

REST, Microservices

Platforms

MacOS, Visual Studio Code (VS Code), Docker, Android, Bitrise, iOS, Apache Kafka, Kubernetes, Amazon Web Services (AWS)

Storage

NoSQL, Redis, PostgreSQL

Other

Software Engineering, Technical Leadership, Team Mentoring, Component Libraries, Cross-platform App Development, ESLint, GitHub Actions, System Design, Third-party Integration, Phoenix LiveView, Full-stack, Fintech, SaaS, APIs, API Integration, Real-time Data, Vite, PDF, Application Modernization, Temporal, Cryptography

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring