Marko Pađen
Verified Expert in Engineering
Software Developer
Berlin, Germany
Toptal member since August 13, 2019
Marko has over a decade of experience with large-scale software including architecture, design, coding, testing, documentation, build, and release. He's held a variety of roles throughout his career such as software engineer and architect, technology lead, full-stack developer, scrum master, QA mentor, and DevOps engineer.
Portfolio
Experience
- .NET - 19 years
- SQL - 18 years
- Redis - 7 years
- Test Automation - 7 years
- Elasticsearch - 7 years
- Azure - 6 years
- Amazon Web Services (AWS) - 2 years
- Angular - 2 years
Availability
Preferred Environment
Azure, .NET Core, Azure DevOps
The most amazing...
...design and implementation I did was critical parts of DNS ENUM server with UDP load balancer. It's auto-scalable in containerized environment and low latency.
Work Experience
Full-stack Developer
Leading Telecommunication Company
- Developed payment integrations with Chargebee and Stripe.
- Built multi-tenant CI/CD deployment on Azure DevOps and Kubernetes.
- Coordinated team efforts on the entire front-end, back end, and DevOps development effort.
Senior Developer | Enterprise Finance Ops
Wegmans
- Developed and maintained code and pipeline for internal financial products.
- Developed new financial services for Azure event-driven workflow.
- Updated and supported legacy applications with the latest frameworks/security patterns.
Full-stack Developer
Marketing product
- Developed Blazor server admin portal and MediatR-based back-end service.
- Established the integration with many marketing providers with recurring Hangfire jobs.
- Worked with multi-stage AKS CI/CD with disposable environments.
Senior .NET Full-stack Developer
Communauto, Inc
- Implemented and tested modern security patterns for legacy applications.
- Upgraded front-end frameworks to the latest version with many braking changes.
- Tested the entire IT system for security vulnerabilities, including web and REST.
Senior Back-end Developer
Leading Content SaaS Company
- Developed API integrations with official regulators worldwide.
- Developed event-based fast data processing services.
- Worked on improving code quality by centralizing and organizing documentation and standards.
Senior Full-stack Developer
Gemini Diversified Services
- Worked on new and existing features in a client-facing Angular application on the front and back end (REST MVC Web API).
- Developed new features for the back-office portal in .NET MVC with Entity Framework over an Azure SQL database.
- Implemented CI/CD with SonarCloud static code analysis, gated pull request, and automated policy-based deployment in Azure DevOps.
- Maintained and improved multiple Azure deployments, including orchestrated deployments, network, and security.
Lead Developer
Online Coaching Portal
- Managed and led a team of four developers working on an online coaching platform.
- Worked as front-end, back-end developer, and DevOps. Implemented Twilio WebRTC and Stripe Connect integrations as well as SignalR chat and notification system.
- Developed CI/CD with continuous testing and disposable Azure environments.
.NET/Angular Developer
Most Investments, LLC Pantheon Software
- Worked on ASP.NET core REST API, backed with Entity Framework and Microsoft SQL Server.
- Worked on Angular front end with Bootstrap and SurveyJS controls.
- Implemented functional JMeter testing for REST API.
- Implemented Jasmine/Karma UI tests.
- Improved Docker setup.
Technology Team Lead - External
Roche
- Worked as the tech lead for a project that had Angular in the front end and .NET Core in the back end.
- Developed custom control to fit our current project, and also worked on architectural tasks like HTTP client mocking, build-time configuration, code coverage CI integration, and similar.
- Developed REST API with all the best practices, large file uploads, Azure hosting, and so on.
- Set up CI/CD and Terraform Azure environment creation.
Head of Software Development
Mitto
- Collaborated with team members on technically and domain challenging tasks.
- Led conversations with the team regarding technology usages and improvements.
- Set up CI/CD according to our internal process. This included release management, testing, development, disposable environments, and nightly builds.
- Developed custom DNS UDP ENUM load balancer used in auto-scalable environments in the cloud.
- Developed custom Prometheus integrations that work well on auto-scalable environments.
Senior Software Engineer
Mitto
- Acted as the full-stack developer on https://www.nimbow.com/. Made some interesting features, like auto-extraction of uploaded Excel files of any structure.
- Served as the technology lead on Number Lookup Services. Developed a performant lookup system.
- Designed system improvements to migrate from the data center. In the cloud, we achieved 2,000/s requests served with less than <100ms. The pure time of our system was <20ms, the rest of 80ms was an external dependency.
- Introduced AOP practices based on static proxy and IL weaving to solve problems like DB connection pool management (cluster-ready), generic caching, RPC calls.
Senior Software Developer
IGT
- Contributed to full-stack development and testing betting software. Developed an interesting MVVM-based event-driven model for betting views - performant on rendering multiple views on multiple screens.
- Mentored team members on new technologies, like WPF, Postsharp, and similar.
- Presented new technologies in-house during development technology stack improvement program. Had a task of presenting WPF with all the benefits it gets on our use cases.
- Mentored 2nd level support and provided them assistance on remote administration tools developed in-house.
- Developed generic tools for using various POS devices in betting.
Software Developer
IT Excellence
- Created custom Kendo UI-based application that imports Excel with Pivot table and creates proper OLAP cubes used later for ETL processes.
- Developed web and Windows Phone part of the application that is a social network for public issues.
Software Developer
Best Solution Team
- Developed custom HTML-based controls for ASP.NET (like flex-grid, control alignment helpers).
- Developed MS Office plugins which integrate with our web portal.
- Integrated ActiveX TWAIN controls into our portal.
- Automated MS Office processes with ClosedXML framework.
Software Developer
LMG Group
- Made XML-based configurable white label web site for selling mobile content (Java games, MIDI ringtones, images, videos).
- Integrated phone model database with auto-detecting features.
- Integrated with mobile providers in a secure way. Handled payments.
Software Engineer
PR Padjen
- Developed custom TCP/IP application protocol for live distributed ERP work.
- Made imports from many popular small ERP systems used locally (MS SQL, IMB db2, FoxPro).
- Made distributed licensing mechanism with payment portal with admin access.
Experience
Imperfect Dollop
https://github.com/notmarkopadjen/imperfect-dollopUseful for serving not-so-time-sensitive data to many clients. It has all the benefits of the in-memory cache with added distributed synchronization.
Azure DevOps Workflow
https://marketplace.visualstudio.com/items?itemName=mitto-ag.workflowRedis Insights
CodinGame Member
https://www.codingame.com/profile/7d385fb020073138ae675a9b4c82a42e5463662ID: not_marko_padjen
Number Lookup
Nimbow
Full-stack developer, part of a larger team.
Sports Betting
Education
Master of Science Degree in Informational Systems and Technologies
Faculty of Organizational Sciences - Belgrade, Serbia
Bachelor of Science Degree in Informational Systems and Technologies
Faculty of Organizational Sciences - Belgrade, Serbia
Certifications
Professional Scrum Master I
Scrum.org
Elasticsearch Developer I
Elastic
Galera Cluster for MySQL and MariaDB training
FromDual
Microsoft Certified Solutions Developer: Windows Store Apps Using C#
Microsoft
Microsoft Specialist - Programming in C# Specialist
Microsoft
Microsoft Certified Professional
Microsoft
Skills
Libraries/APIs
Entity Framework, Windows Forms (WinForms), REST APIs, Vue, Web API, Azure Blob Storage API, SurveyJS, jQuery, XNA, SignalR, Twilio API, Stripe Connect, MediatR
Tools
xUnit, Microsoft Unit Tests, TFS, Git, Apache JMeter, NAnt, PostSharp, RabbitMQ, SoapUI, Keyboards, Microsoft Silverlight, Microsoft Access, Terraform, Oracle Coherence, TeamCity, ActiveMQ, NuGet, Twilio Programmable Video, Jira, NPM, Azure Kubernetes Service (AKS), Hangfire
Languages
Java, C#, SQL, HTML, HTML5, VB.NET, JavaScript, TypeScript, CSS, UML, MDX, Go, Active Server Pages (ASP), C#.NET
Frameworks
ASP.NET Web API, .NET, .NET Core, NUnit, Blazor, SpecFlow, ServiceStack, ASP.NET, ASP.NET Core 2, ASP.NET MVC, ASP.NET Core MVC, Kendo UI, Kendo UI MVVM, Selenium, Angular, Windows Presentation Foundation (WPF), Bootstrap, Jasmine, Entity Framework Core, ASP.NET Core, AWS HA, Ext JS, Windows PowerShell, Cypress, Bootstrap 3+
Paradigms
Azure DevOps, Object-oriented Design (OOD), Microservices Architecture, Load Testing, Design Patterns, Agile, Test Automation, Object-oriented Programming (OOP), Scrum, AOP, Dependency Injection, Microservices, REST, DevOps, Aspect-oriented Programming (AOP), YAGNI, DRY, Clean Architecture
Storage
MySQL, Redis, Microsoft SQL Server, Elasticsearch, Azure Cosmos DB, Databases, RavenDB, DB, Azure Table Storage, Azure SQL, MariaDB, Oracle PL/SQL, SQL Server Integration Services (SSIS), Azure Queue Storage, PL/SQL, Azure Blobs
Platforms
Amazon Web Services (AWS), Docker, Azure, Azure PaaS, iOS, Azure Event Hubs, Oracle Database, Windows Phone, Oracle, Kubernetes, Microsoft, Azure Functions
Other
Visual Studio Team Services (VSTS), Release Management, APIs, Galera Cluster, WCF Web Services, IT Recruitment, Web Applications, Team Leadership, Containerization, Network Protocols, IoC, Orchestration, Office Plugins, Algorithms, Patterns, Cloud, Azure Stream Analytics, Plugins, Windows Communication Foundation (WCF), TCP/IP, DevExpress, POS, Azure Service Bus, API Integration, Azure Resource Manager (ARM), SQL Server 2015, Web Security, Fuzzy Logic, Neural Networks, Software Engineering, Software Integration, Network Engineering, Systems, Statistics, Mathematics, Operational Control, Windows Store, Microsoft Data Transformation Services (now SSIS), SAP, PL/SQL Tuning
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