Dmitry K. Maslennikov, Developer in Budva, Budva Municipality, Montenegro
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Dmitry K. Maslennikov

Verified Expert  in Engineering

Machine Learning Developer

Budva, Budva Municipality, Montenegro
Toptal Member Since
March 24, 2017

As a seasoned software expert, Dmitry has a broad range of experience in software development using modern and time-tested technologies. Throughout his 20-year career, he's had the opportunity to work on multiple large-scale projects and numerous smaller projects, honing his skills as a software developer, software architect, team leader, and consultant. Dmitry's dedication to excellence in the field has been recognized through multiple certifications.


Amazon Web Services (AWS), GitLab, Jira, Trello, Moqups, MongoDB, Apache POI...
PSI Mobile (via Toptal)
Node.js, Seneca.js, PM2, MongoDB, RxJS, Angular Material, Angular
Firebase, AngularJS, Apache ZooKeeper, Apache Spark, Apache Kafka, Architecture...




Preferred Environment

Git, IntelliJ IDEA, Amazon Web Services (AWS), Java

The most amazing... I've built is a successful big data project where I handled all phases, from the architecture and design to the delivery stage.

Work Experience

Head of Engineering

2017 - 2023
  • Led and managed a team of software developers, resulting in industry-leading and innovative software solutions.
  • Delivered the project within budget and on time while fostering a professional team culture.
  • Did hands-on technical recruitment, performance management, and training of team members.
  • Mentored and performance-managed team members to reach their full potential.
  • Performed strategic decision-making for company products and services, balancing emerging and legacy technologies.
  • Ensured continuous education and application of current software development technologies and methodologies.
  • Conducted a thorough review and resolution of critical support issues through legacy code auditing.
  • Maintained high code quality standards with over 900,000 lines of code and 350,000 lines of test coverage.
  • Developed and implemented a unique PDF conversion mechanism through data scraping, resulting in increased efficiency and productivity.
  • Fostered an environment of new ideas and proactive technical-business discussions.
Technologies: Amazon Web Services (AWS), GitLab, Jira, Trello, Moqups, MongoDB, Apache POI, REST, Spring Boot, Java, RxJS, Angular, SOC 2, Architecture, IT Security

Senior Angular 2 Developer

2017 - 2018
PSI Mobile (via Toptal)
  • Created client-side services and components on Angular 4 framework.
  • Built the UI using the Angular Material framework.
  • Debugged the Node.js and Seneca server-side for different platforms.
Technologies: Node.js, Seneca.js, PM2, MongoDB, RxJS, Angular Material, Angular

Software Architect | Developer | Project Manager

2016 - 2017
  • Processed and analyzed a stream of data from temperature sensors from different places in the world.
  • Used Apache Kafka as a publishing/subscribing messaging system; the sensors acted as publishers.
  • Implemented Apache Spark Streaming so that it receives information through Kafka, analyzes it in real-time, and publishes it in Firebase.
  • Developed an Angular application which receives data from Firebase and display analytics.
Technologies: Firebase, AngularJS, Apache ZooKeeper, Apache Spark, Apache Kafka, Architecture, Jakarta Server Pages (JSP)

Software Architect

2011 - 2017
  • Designed and implemented a robust software architecture for a mission-critical enterprise system, ensuring high levels of functionality and performance.
  • Managed the development of scalable and secure software solutions, aligning with business objectives and long-term goals.
  • Designed and implemented agile methodologies and DevOps practices to improve software development processes, resulting in faster delivery time.
  • Streamlined software release processes through the development of a continuous integration and deployment pipeline.
  • Conducted code reviews, technical assessments, and design sessions to ensure adherence to high-quality software development practices and industry standards.
  • Mentored and provided technical leadership to a team of software developers, resulting in increased productivity and team efficiency.
  • Reduced technical debt through proactive management of technical issues and effective remediation strategies.
  • Designed a scalable, secure, and flexible architecture that supported company growth. Improved software quality through the adoption of code review practices and technical assessments.
  • Mentored junior software developers, fostering a culture of continuous learning and professional development.
Technologies: Gorm, Microsoft SQL Server, Vaadin, Grails, Hibernate, Spring, Jakarta EE, Jakarta Server Pages (JSP), Java Servlets, Java, Architecture, IT Security

Software Architect | Developer | Project Manager

2010 - 2017
  • Developed a medical equipment storage system (storage accounting, purchases/sales, and client interaction) for a medical equipment reseller.
  • Included multiple users, millions of equipment items, and an extended report system.
  • Made the system in 2010, and it is currently the main daily used system in those companies without the need for much maintenance.
Technologies: Vaadin, Servlet, Java, InterBase, Firebird, Architecture, IT Security, Jakarta Server Pages (JSP)

Chief Programmer

2006 - 2011
  • Worked for the ACC planning department. Achieved expertise in leading software development projects for budget planning, working closely with analysis, testing, maintenance, and adoption teams to ensure the successful completion of projects.
  • Drove the development and improvement of existing software, as well as the creation of new functional software for budget planning, designed for full automation across various levels of government, from federal subjects to municipalities.
  • Demonstrated leadership skills by catalyzing software development progress via design and developing new subsystems, including architecture development, task division, initial assessment, and programming.
  • Handled task distribution among the development team, ensuring efficient project management.
  • Implemented effective production management techniques and significantly contributed to improving the system through active learning and developing effective approaches and methodologies for development.
  • Included unit testing, code inspection, continuous integration, increased transparency, and code maintainability.
  • Developed and refined leadership skills continuously, embracing the best approaches and methodologies for software development, resulting in exceptional project outcomes.
Technologies: Firebird, Oracle, Apache POI, ZKoss, Ext JS, Jakarta EE, J2SE, Java, IT Security

Software Developer

2003 - 2006
  • Played a key role in ensuring software testing quality through comprehensive testing of call center system interfaces and functionalities.
  • Developed and completed IVR projects successfully, utilizing a dedicated scripting language, meeting requirements specifications, and demonstrating proficiency in scripting for MySQL databases.
  • Demonstrated expertise in programming voice services for mobile phones using MS SQL, completing over 20 major projects and providing effective debugging and error correction in stored procedures.
  • Designed and developed highly reliable service applications using Delphi 7, running 24/7 and efficiently transferring LOG files to databases through multi-threading and optimizing memory usage and CPU time.
  • Innovated in developing an application error analysis system for LOG files, enhancing system efficiency and providing valuable insights for improved performance.
Technologies: MySQL, Microsoft SQL Server, Delphi, Java, IntelliScript, IT Security

Smart Celsius Big Data Project

Smart Celsius is a bunch of applications that were used in a big data technology stack. It was used as a prototype for an international company specializing in IoT.

It processes and analyzes a stream of data from temperature sensors from different places in the world.

Technology Stack:
• Apache Kafka as a publishing/subscribing messaging system; the sensors acted as publishers.
• Apache Spark Streaming receives information through Kafka, analyzes it in real-time, and publishes it in Firebase.
• The Angular JS application receives data from Firebase and display analytics.

Real-time Planning System

It was a big project that involved the migration from hundreds of Google spreadsheets to a completely solid solution for a Fortune 500 international company.

The main goal of this project was backward compatibility and enable the ability for multiple users to simultaneously work with planning data while updating it in real-time.

Technology Stack:
• AngularJS for the front end. The front end was fully tested with client-unit testing frameworks: Karma and CasperJS.
• Firebase for the back end. The back end was secured with Firebase security rules to separate access rights to the database.

Event Presentation System

The project was developed for a big international company with headquarters in Switzerland. The main goal of this project was scalability for 1,000 simultaneous users.

We achieved it by dividing the software into two parts: the front-end (AngularJS and Bootstrap with a responsive design for different platforms) and the back-end (Java endpoints on the Google App Engine platform).

This project included the Google API for many features. I used the Google App Engine for setting-up the user credentials (for OAuth client authorization and Google App scripts authorization), using the Google API (Google Spreadsheets, Google Forms, Google Charts, Google Sites, Drive API, Mail API, YouTube API, Google Speech API) on the client-side (AngularJS, Bootstrap, and iPhone), Google endpoints as the main web services, Google Channels (WebSockets) for real-time users interactions, and the Google Datastore as the main database.

Medical Equipment Storage System

This is the storage accounting, purchase/sale, and client interaction system for a medical equipment reseller. The application was born in 2010 and currently, it is the main daily-use system in those companies without the need for much maintenance.
1999 - 2005

Master's Degree in Rocket Engines

Bauman Moscow State Technical University - Moscow, Russia


Building Containerized Applications on AWS



Blockchain Specialization

The State University of New York at Buffalo


Blockchain Platforms

The State University of New York at Buffalo


Decentralized Applications (ÐApps)

The State University of New York at Buffalo


Smart Contracts

The State University of New York at Buffalo


Blockchain Basics

The State University of New York at Buffalo


Angular Academy Certificate



Vaadin 7 Certified Developer



Functional Programming Principles in Scala



Sun Certified Web Component Developer for the Java Platform, Enterprise Edition 5

Oracle Corporation


Sun Certified Programmer for the Java Platform, Standard Edition 6

Sun Microsystems, Inc.


RxJS, REST APIs, Apache POI, Google API, Java Servlets, Node.js, Seneca.js, Spark Streaming, Aspose Components


GitLab, IntelliJ IDEA, GitLab CI/CD, Bitbucket, GitHub, Git, Jira, REST Assured, Servlet, Moqups, Trello, PM2, AngularFire, Angular CLI, Apache ZooKeeper, Spark SQL, LumX, CasperJS


Angular, Angular Material, AngularJS, Spring Boot, Grails, Jersey, Spring, Hibernate, JUnit, Vaadin, Ext JS, Jakarta Server Pages (JSP), GWT, GAE, Google Cloud Endpoints, Redux, Android SDK, Apache Spark, ZKoss, Gorm


Amazon Web Services (AWS), Firebase, Google App Engine, J2SE, Jakarta EE, Apache Kafka, Spark Core, Oracle, Android, Blockchain


Java, Java 8, TypeScript 2, TypeScript, HTML, CSS, JavaScript, SQL, Google Apps Script, Delphi, HTML5, Scala


MongoDB, NoSQL, InterBase, MySQL, Microsoft SQL Server, Firebird, PostgreSQL, H2


Continuous Integration (CI), Agile, Test-driven Development (TDD), Agile Software Development, REST


Architecture, Serverless, SOC 2, IT Security, Google, WebSockets, Big Data, Higher Education, ÐApp, Smart Contracts, Machine Learning, IntelliScript

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