Boldizsar Akos Mezei, Developer in Budapest, Hungary
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Boldizsar Akos Mezei

Verified Expert  in Engineering

Team Lead and Full-stack Developer

Budapest, Hungary
Toptal Member Since
March 17, 2020

Boldizsar is a Java/Scala back-end developer who has worked at Morgan Stanley on a group of microservices. His primary focus is backend development but he is also open for Android development. Boldizsar considers himself a hybrid in the sense that he is highly business-focused. When dealing with tasks, he would rather choose the inconvenient, unusual way to achieve the best outcome both for the client and the project itself.


NXT Mortgage
Infrastructure, Web Development, Google Cloud, GitLab CI/CD, GitLab...
Morgan Stanley
Model View ViewModel (MVVM), Fintech, Scalable Web Services...




Preferred Environment

Linux, MacOS, Visual Studio Code (VS Code)

The most amazing...

...thing I have done was reduce the data size transferred over the network between micro services by 50%.

Work Experience

Team Lead and Full-stack Developer

2020 - 2021
NXT Mortgage
  • Worked as a full-stack developer and tech and team lead.
  • Oversaw the complete development lifecycle of the project that relied entirely on a Cloud infrastructure.
  • Created CI/CD pipelines that highly increased team productivity.
Technologies: Infrastructure, Web Development, Google Cloud, GitLab CI/CD, GitLab, Communication, Remote Team Leadership, Technical Leadership, Team Leadership, Material UI, Firebase Authentication, Architecture, Firebase Cloud Functions, Scalable Web Services, Single-page Applications (SPA), Web App Deployment, Node.js, Visual Studio Code (VS Code), Scrum, Agile, TypeScript, Full-stack, Git, React, Firebase, Back-end Development, Back-end, Lambda Functions, SaaS, APIs

Java/Scala Developer

2018 - 2020
Morgan Stanley
  • Upgraded a group of microservices to use a more efficient way of serializing and sending data through the web—transferring the same amount of information in a 50% smaller size reduced the execution time and running costs for the firm.
  • Collaborated with peers worldwide (India, London, New York) to upgrade a legacy Java system to use the most up-to-date Java, Gradle, and Spring versions.
  • Created an API for an immense Scala-based back-end project. This allowed several upstream services to communicate directly with this component, thus allowing the smoothest flow for a million dollars worth of transactions.
  • Onboarded Agile methodologies that increased developer productivity by 30% and reduced time to market by 20%.
  • Mentored several new team members and junior software developers, both personally and professionally.
Technologies: Model View ViewModel (MVVM), Fintech, Scalable Web Services, Test-driven Development (TDD), Scrum, Agile, RESTful Microservices, Full-stack, Git, REST APIs, JUnit, Spring Boot, SQL, Microservices, Databases, Spring 4, Hibernate, Jira, Back-end Development, Back-end, Gradle, Google Protocol Buffer, Spring

Portfolio Risk and Margin Calculator

I was a back-end developer for a Java-based application, organized into microservices. The project's main goal was to provide real and non-real-time risk and margin calculations for portfolios. My main task was to onboard new functionalities and upgrade the current system to use the newest technologies. While doing so, I had to communicate and coordinate tasks around the world as the global team sits in India, London, and New York as well.

Loan Providing Web App
An Angular and Firebase web app for loan providing. I was the back-end developer for an existing loan providing web app. During this project, my main task was to clean up the existing Firebase Cloud functions to ensure higher stability and lower running costs. I also created automated CD and CI jobs to save developer's time, thus reducing time to market and costs spent on repetitive tasks.

Client testimonial: "I can highly recommend Boldizsar for demanding software development jobs. Boldizsar cares about his work and you can really see it through his communication and professionalism. He managed to grasp our business context and application very quickly and fixed messy code written by the previous developer. Boldizsar delivered tasks always on time and most important were pro-actively fixing issues or suggesting improvements."


A React and Firebase-based ticketing platform for the Australian tourism industry.

In the beginning, I was the back-end developer for this project. As the project grew and we hired more developers, I became a full-stack developer and tech/team lead. My role was to oversee the complete development lifecycle of the project, add and upgrade new features on the back-and-front-end site, and organize tasks among team members.

PHirst App

An emergency app for those who connect, respond, and care (the published app is in an MVP state.)
Initially, I was the back-end developer for this app. My role was to provide a stable and highly scalable back-end service for the iOS/Android-based front end. Soon, as the project grew, I took the initiative and became the tech/team lead and full-stack developer. After that, my job became more complicated as I had to manage the team and be responsible for the Android front end.
2015 - 2018

Bachelor's Degree in Computer Science

Babeș-Bolyai University - Cluj Napoca, Romania


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


GitHub, Jira, Firebase Authentication, GitLab, GitLab CI/CD, Git, IntelliJ IDEA, Android Studio, Gradle, SendinBlue, Perforce, Mongoose


Jest, Hibernate, Spring 4, Spring, Ktor, Spring Boot, JUnit, Material UI, Google Protocol Buffer, React Native, Flutter, Express.js


Kotlin, SQL, TypeScript, Java, Scala, JavaScript, CSS, HTML, Rust, GraphQL


Requirements Analysis, Scalable Application, Back-end Architecture, Web Architecture, Asynchronous Programming, Concurrent Programming, Microservices, Microservices Architecture, REST, Agile, Model View ViewModel (MVVM), Clean Architecture, Scrum, Testing, Test-driven Development (TDD), DevOps


JVM, Firebase, Linux, Android, Docker, Windows, Visual Studio Code (VS Code), Amazon Web Services (AWS), Azure, MacOS


Cloud Firestore, Google Cloud, Databases, PostgreSQL, NoSQL, MySQL, MongoDB


Web App Deployment, Single-page Applications (SPA), Back-end, Scalable Web Services, Serverless, Lambda Functions, SaaS, Firebase Cloud Functions, Web App UI, Communication, Web Development, Infrastructure, Front-end, User Interface (UI), Software Architecture, API Integration, Back-end Development, RESTful Microservices, Multithreading, APIs, Architecture, Fintech, Stripe Payments, Team Leadership, Technical Leadership, Remote Team Leadership, Message Queues, Full-stack, Cloud Storage

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