Мар'ян

MARIAN BAHNIUK
Senior / Lead Java Backend & Full-Stack Engineer
Ukraine · Remote | Java 21 · Spring Boot · Microservices · AWS · PostgreSQL · Docker · Angular · TypeScript · Next.js ·
NestJS
Linkedin: [відкрити контакти](див. вище в блоці «контактна інформація»)
Email: [відкрити контакти](див. вище в блоці «контактна інформація»)

PROFESSIONAL SUMMARY
Senior Software Engineer with 24+ years of IT experience spanning software development, backend engineering, full-stack development, system
administration, technical support and technical leadership. Strong recent focus on Java, Spring Boot and microservices, with hands-on experience
designing, developing, maintaining and migrating distributed systems. Broad full-stack background with 10+ years of Angular/TypeScript experience and
additional Next.js, NestJS, Node.js, React, Vue.js and Electron experience. Experienced in complex technical investigation, code review, knowledge
sharing, migrations, cloud infrastructure and production support.

CORE COMPETENCIES
Backend: Java, Spring, Spring Boot, REST APIs, Hibernate/JPA, Node.js, NestJS
Architecture: Microservices, distributed systems, API design, system integration
Frontend: Angular, TypeScript, JavaScript, Next.js, React, Vue.js
Cloud & DevOps: AWS, DigitalOcean, Docker, GitHub Actions, Bitbucket Pipelines
Databases: PostgreSQL, MySQL, MS SQL
Systems: Linux, FreeBSD, Windows, networking, server administration

PROFESSIONAL EXPERIENCE
GeeksForLess Inc. — Remote | 2021–2026
Lead Java Developer / Full-Stack Developer
• Led and contributed to complex Java-based microservices systems, including migration and modernization work.
• Investigated complex backend and player-side software issues across distributed Java and JavaScript/Node.js components.
• Developed products using Java 21/Spring Boot, NestJS, Angular and Next.js.
• Handled AWS and DigitalOcean infrastructure and GitHub/Bitbucket CI/CD deployments.
• Worked with third-party integrations including hotel-booking APIs and DOKU payments.
• Supported technical problem solving, code quality, knowledge sharing and production troubleshooting.
Technologies: Java 8–21, Spring Boot, Microservices, Node.js, NestJS, Angular, Next.js, Docker, AWS, DigitalOcean, GitHub Actions, Bitbucket
GeeksForLess Inc. — Remote | 2020–2021
Technical SME / Senior Full-Stack Developer
• Implemented and maintained product functionality across backend and frontend layers.
• Worked with Java/Spring Boot and supported technical investigation, debugging and code quality.
• Contributed to web applications using Angular and TypeScript.
Technologies: Java 8+, Spring Boot, Angular, TypeScript
Slate — Remote | 2020
Senior Web Developer
• Developed and maintained a web/mobile platform for managing social content.
• Implemented features, tests and bug fixes.
Technologies: Angular 8+, TypeScript, CSS/SCSS, Bootstrap
NDA Projects — Remote | 2018–2020
Full-Stack Software Developer
• Developed web, desktop and backend applications, including cryptocurrency, healthcare and time-tracking systems.
• Built backend functionality with Java/Spring Boot, Node.js and .NET and frontend functionality with Angular, React and Vue.js.
• Worked with REST APIs, automated testing, Docker/Vagrant environments and AWS.
Technologies: Java, Spring Boot, Hibernate/JPA, Node.js, TypeScript, Angular, React, Vue.js, ElectronJS, .NET, Docker, AWS
KSF LTD — Kyiv / Remote | 2017–2018
Frontend → Full-Stack Software Developer
• Developed Angular applications and REST API functionality using Java and Node.js.
• Worked with Java/WildFly, Hibernate/JPA, database changes and AWS.
Technologies: Angular 2–6, TypeScript, Redux, Java, WildFly, Hibernate/JPA, Node.js, AWS
SoftServe — Kyiv, Ukraine | 2014–2017
Software Developer
• Worked on international web, cloud, analytics and business applications across frontend and backend tasks.
• Developed and maintained Angular/JavaScript interfaces and contributed to backend/cloud functionality.
Technologies: AngularJS/Angular 2+, TypeScript, JavaScript, Node.js, Java, Python/Django, WebGL, HTML/CSS
PortaOne — Chernihiv, Ukraine | 2010–2014
Software Developer / Support Engineer
• Supported complex SIP/VoIP and billing products and investigated production issues.
• Developed backend/frontend functionality, SOAP scripts and tooling for large-log analysis.
Technologies: Java, Perl, PostgreSQL, MySQL, Linux, FreeBSD, SOAP, XML, JavaScript, jQuery
Earlier Career | 1994–2010
Software Developer / System Administrator / Support

Marian Bahniuk — ATS CV + Detailed Description Page 1

• Software development, ISP/network administration, web development and technical support.
• Administered 30+ servers and 500+ workstations and worked across Linux, FreeBSD and Windows environments.
Technologies: C/C++, Perl, PHP, Linux, FreeBSD, Windows, PostgreSQL, MySQL, Apache, networking

EDUCATION
Ivano-Frankivsk State Technical University of Oil and Gas, Ukraine — Engineer of Ecology, 1994–1999

LANGUAGES
English — Upper-Intermediate Strong

DETAILED DESCRIPTION
This section preserves and professionally restructures the detailed project and career information from the source CV. It is intentionally more
comprehensive than the recruiter-facing summary and serves as a technical career archive.
Ivano-Frankivsk State Technical University of Oil and Gas — Ivano-Frankivsk, Ukraine | 1994–1998
Laboratory Assistant, PC Laboratory of the Ecology Department
Project: Computer Laboratory of Ecology
• Prepared publications and project descriptions.
• Supported teaching and PC-laboratory activities.
• Worked with office and graphics software in the laboratory environment.
Technologies: Windows 3.11, Windows 95, GIS, Word, Excel
Freelancer / Game Club System Administrator — Ivano-Frankivsk, Ukraine | 1999–2001
Freelancer / Game Club System Administrator
Project: Game Club System Administration
• Provided system administration and operational support for a computer game-club environment.
Technologies: Windows 95, C++ (Windows)
InterLink ISP — Ivano-Frankivsk, Ukraine | 2001–2002
System Administrator Assistant / Support Engineer
Project: InterLink ISP
• Performed DNS/hostmaster activities.
• Installed and configured v.34 modems.
• Supported Windows users and PCs.
Technologies: FreeBSD, named/BIND, Windows, v.34 modems
ChernigovNefteGasGeologiya — Chernihiv, Ukraine | 2003
Software Engineer / Developer / System Administrator
Project: Oil and Gas Project Development
• Developed and supported two internal applications from scratch for engineering calculations.
• Built functionality to automate calculation of project and financial parameters for water wells.
• Built functionality to calculate and graph combined pressures of petroleum wells.
• Administered local servers and supported Windows users and PCs.
Technologies: Linux, FreeBSD, Windows, Apache, Microsoft Visual C++ 6.0, WinAPI, Ethernet
CityNet ISP — Ivano-Frankivsk, Ukraine | 2003–2006
System Administrator Assistant / Support Engineer / Sales Manager / Software Engineer
Project: CityNet Internet Service Provider
• Performed system-administration, technical-support and sales functions.
• Installed and supported LAN infrastructure.
• Installed, configured and supported 802.11b/g wireless equipment and VoIP devices.
• Developed and supported the ISP website and customer websites.
• Developed internal administration and monitoring tools.
• Developed and supported an internal ISP notification application.
Technologies: Linux, FreeBSD, Windows, Apache, PostgreSQL, Perl, PHP, C/C++, RRDtools, CSS, HTML, Ethernet, Wi-Fi, VoIP
Gipermarket Vena — Chernihiv, Ukraine | 2006–2010
System Administrator
Project: Infrastructure for a Hypermarket with Offices across Ukraine
• Administered 30+ servers and 500+ PCs across offices.
• Provided server and workstation administration and technical support.
Technologies: Linux, FreeBSD, Windows, Apache, PostgreSQL, OpenVPN, Dovecot, Exim, Perl, Radmin
PortaOne — Chernihiv, Ukraine | 2010–2012
Support Engineer
Project: PortaOne SoftSwitch
• Supported a SIP/VoIP business solution integrating PSTN and VoIP hardware/software for calling and customer billing.
• Developed SOAP scripts.
• Analyzed large application logs using Perl and C.
• Investigated software issues and production problems.
Technologies: Linux, FreeBSD, Perl, MySQL, HTML4, CSS, JavaScript, jQuery, AJAX, Apache, Mason, XML
PortaOne — Chernihiv, Ukraine | 2012–2014
Software Developer
Project: PortaOne MetroBilling

Marian Bahniuk — ATS CV + Detailed Description Page 2

• Developed frontend functionality for a utility-meter management and billing solution.
• Developed backend functionality using Perl, PostgreSQL and Java.
• Worked on a system for monitoring electricity, water, gas and other meters, collecting usage information and billing customers.
Technologies: Amazon Cloud, Linux, Perl, PostgreSQL, HTML4, CSS, JavaScript, jQuery, Apache, Mason, XML
PortaOne — Chernihiv, Ukraine | 2014
Software Developer
Project: PortaOne SoftSwitch
• Developed frontend functionality using HTML5, CSS3 and ExtJS4.
• Developed backend functionality using Perl and MySQL.
Technologies: Linux, Perl, MySQL, HTML5, CSS3, ExtJS4, Apache, Mason, XML
SoftServe — Kyiv, Ukraine | 2014
Software Developer
Project: NDA — Web Presentation with 3D Graphics
• Selected technologies and designed the program structure.
• Implemented an interactive browser presentation with an administration page and 3D model navigation.
Technologies: AngularJS, JavaScript, BabylonJS, WebGL, Corel Draw, Adobe Photoshop, GIMP
SoftServe — Kyiv, Ukraine | 2014
Software Developer
Project: NDA — Tracking System with Web Interface
• Developed web UI functionality and fixed defects.
Technologies: JavaScript, AngularJS
SoftServe — Kyiv, Ukraine | 2015
Software Developer
Project: NDA — Farm Credit Search Site (USA)
• Developed web UI functionality and fixed defects for a site used to find lenders.
Technologies: JavaScript, jQuery, Visual Studio, SVG
SoftServe — Kyiv, Ukraine | 2015
Software Developer
Project: NDA — WordPress Site (Europe)
• Migrated the site to a VM environment.
• Redesigned database and UI components.
• Developed web UI functionality and fixed defects.
Technologies: WordPress, JavaScript
SoftServe — Kyiv, Ukraine | 2015–2016
Software Developer
Project: NDA — Complex System for Selling Products, Energy Management and CRM (Europe)
• Developed web UI functionality and fixed defects.
• Worked on a system composed of multiple interacting websites supporting product sales, energy-usage statistics and CRM-related functionality.
Technologies: AngularJS, JavaScript, NodeJS, Bower, Grunt, Apache
SoftServe — Kyiv, Ukraine | 2016
Software Developer
Project: NDA — Security System Presentation Site (Europe)
• Developed web UI functionality and fixed defects for a presentation/navigation site.
Technologies: AngularJS, JavaScript, NodeJS, Bower, Gulp
SoftServe — Kyiv, Ukraine | 2016
Software Developer
Project: NDA
• Performed web UI development and bug fixing.
Technologies: AngularJS, CSS, HTML, Java
SoftServe — Kyiv, Ukraine | 2016
Software Developer
Project: NDA — Complex Cloud System (Europe)
• Contributed partially as a backend software engineer.
• Developed web UI functionality and fixed defects.
• Worked with a cloud-services environment.
Technologies: AngularJS, jQuery, JavaScript, Python, Django, Horizon
SoftServe — Kyiv, Ukraine | 2016–2017
Software Developer
Project: NDA — Complex System (Canada)
• Developed web UI functionality for a system containing several Big Data analysis services.
• Worked with state management and Angular tooling.
Technologies: Angular2, TypeScript, Redux, angular-cli/Webpack, NodeJS investigation
KSF LTD — Kyiv, Ukraine / Remote | 2017–2018
Frontend Software Developer → Full-Stack Software Developer
Project: NDA — Several Music Management Projects (Europe)

Marian Bahniuk — ATS CV + Detailed Description Page 3

• Developed web UI functionality for several related music-management products.
• Designed database changes.
• Implemented REST endpoints using Java and Node.js.
• Fixed defects and contributed to backend development.
• Also worked on one Ionic project, though it was not the primary assignment.
Technologies: Angular2–Angular6, TypeScript, Redux, angular-cli, Java/WildFly, Hibernate/Persistence, NodeJS mock backend, shell scripts, AWS, Ionic
Bizico — Chernivtsi, Ukraine / Remote | 2018
Frontend Ionic3/Angular5 Software Developer
Project: NDA — Android/iOS Application for Managers and Users
• Developed mobile UI for an application used by divers and managers to verify drivers' licenses.
• Integrated REST APIs and an SDK for scanning licenses.
• Supported photo/video capture, automatic reading of scanned-document data, upload and manager review workflows.
• Wrote tests and fixed defects.
Technologies: Ionic3/Cordova, Angular5, TypeScript, Redux, LocalStorage
NDA — Remote | 2018
Full-Stack Java/Angular6, NodeJS/React Software Developer
Project: NDA — Cryptocurrency Monitoring and Trading System
• Developed the system from scratch.
• Worked on collection and presentation of cryptocurrency-exchange data.
• Implemented functionality for creating, reading, updating and deleting trades.
• Wrote tests and fixed defects.
Technologies: Java/Swing, Java/Spring/Tomcat, NodeJS, Hibernate/Persistence, TypeScript, Angular6, React, Redux, PrimeNG, AWS, Vagrant, Docker,
CSS/SCSS, Symfony/Laravel investigation
NDA — Remote | 2019
Full-Stack Java/Vue Software Developer
Project: NDA — Torrent Download Management System
• Implemented the website backend and frontend from scratch.
• Assisted with the related desktop application.
Technologies: Java/SpringBoot/Tomcat, TypeScript/Vue/Vuex, ElectronJS, CSS/SCSS, Vagrant
NDA — Remote | 2019
Full-Stack NestJS/Vue Software Developer
Project: NDA — Website
• Implemented the website backend and frontend from scratch.
• Wrote tests and fixed defects.
Technologies: NestJS, TypeScript/Vue/Vuex, AntDesign, ElementUI, CSS/SCSS, Vagrant
NDA — Remote | 2019–2020
Angular/Full-Stack Software Developer
Project: NDA — Healthcare System with Several Subproducts
• Implemented frontend functionality and occasionally backend functionality.
• Implemented new features, wrote tests and fixed defects.
Technologies: AngularJS/Angular5+, TypeScript, ASP.NET, CSS/SCSS
NDA — Remote | 2020
Full-Stack Software Developer
Project: NDA — Time Tracking System (Startup)
• Implemented frontend functionality and occasional backend tasks.
• Implemented new features, wrote tests and fixed defects.
Technologies: Angular8/9, TypeScript, .NET, CSS/SCSS
NDA — Remote | 2020
Full-Stack Software Developer
Project: NDA — Cryptocurrency Trading Software (Startup)
• Implemented frontend, desktop and backend functionality.
• Worked on software for trading on exchanges through REST APIs.
• Implemented new features, wrote tests and fixed defects.
Technologies: VueJS/ElectronJS, Angular9, TypeScript, .NET, CSS/SCSS, Bootstrap
Slate — Remote | 2020
Senior Web Developer
Project: Slate — Mobile and Web Social Content Management System
• Implemented new features, wrote tests and fixed defects for a mobile and web system used to manage social content.
Technologies: Angular8+, TypeScript, CSS/SCSS, Bootstrap
GeeksForLess Inc. — Remote | 2020–2021
Technical SME / Senior Full-Stack Developer
Project: NDA
• Implemented new features, wrote tests and fixed defects.
• Worked with Java/Spring Boot as part of the technical stack.
Technologies: Java 8+, Spring Boot
GeeksForLess Inc. — Remote | 2021–2025

Marian Bahniuk — ATS CV + Detailed Description Page 4

Lead Java Developer / Player Software Investigator
Project: NDA — Media Player Management and Monitoring Microservices System
• Supported and helped migrate a complex microservices system.
• Worked on functionality for managing and monitoring media players, including software updates.
• Worked as Lead Java Developer and subsequently performed player-software investigation and related technical work.
• Investigated issues across Java, JavaScript/Node.js, Docker, AWS and player-side code.
Technologies: Java 8+, JavaScript, NodeJS, Docker, AWS, microservices and player-related technologies
NDA — Remote | 2026
Full-Stack Developer / Lead Java / NestJS / Angular / DevOps
Project: Two Small Startup Products
• Worked as Lead Java Developer and NestJS Developer.
• Developed Angular functionality.
• Handled DevOps activities on DigitalOcean and AWS.
• Maintained GitHub and Bitbucket deployment pipelines for several startup products.
• Worked on cryptocurrency software for interaction with Binance.
• Worked on a massage-salon application for scheduling and payment of visits.
• Integrated DOKU payments.
Technologies: Java 21, Spring Boot, NestJS, Angular, GitHub pipelines, Bitbucket, DigitalOcean, AWS, DOKU
GeeksForLess Inc. — Remote | 2026
Full-Stack Developer (Java / NextJS)
Project: NDA — Hotel Booking Project
• Worked as Lead Java Developer and NextJS Developer.
• Handled DevOps activities on AWS and GitHub.
• Integrated the Gimmonix API.
Technologies: Java 21, Spring Boot, NextJS 14, GitHub pipelines, AWS, Gimmonix API

Marian Bahniuk — ATS CV + Detailed Description Page 5