Mihály Tringel, Developer in Budapest, Hungary
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Mihály Tringel

Verified Expert  in Engineering

Microsoft Certified Professional Developer

Location
Budapest, Hungary
Toptal Member Since
December 26, 2017

Mihály is a full-stack developer with a front-end focus and 20 years of experience in software design, development, maintenance, and management. Mihály is well-versed in various technologies, including React, Angular, Blazor, SPA, PWA, HTML5, TypeScript, jQuery, Sass, SCSS, Azure Services, Azure DevOps, ASP.NET Razor, .NET Core, SQL Server, and Unity.

Portfolio

TRM Software Design
Unity, Microsoft SQL Server, .NET Core, HTML5, TypeScript, React, Angular, Azure
Grape Solutions Zrt.
Visual Studio Tools for Office (VSTO), Power View, Power Query, Power Pivot...
Cambridge Technology Partners
SharePoint, XSD, XML, SOAP, Web Services, Microsoft SQL Server, CSS, HTML...

Experience

Availability

Part-time

Preferred Environment

Visual Studio Code (VS Code), Visual Studio

The most amazing...

...project I've implemented is a web spreadsheet component for the FP&A of an insurance company to replace the desktop solution used by more than 3,000.

Work Experience

Full-stack Software Engineer

2015 - PRESENT
TRM Software Design
  • Worked on Toptal assignments as a freelance full-stack or front-end developer using React, Blazor, HTML5, TypeScript, GraphQL, Azure, ASP.NET, .NET Core, and SQL Server.
  • Worked on freelance projects using React, Blazor, HTML5, TypeScript, GraphQL, Azure, ASP.NET, .NET Core, SQL Server, and Power BI.
  • Developed features for Android using Unity and Blender.
Technologies: Unity, Microsoft SQL Server, .NET Core, HTML5, TypeScript, React, Angular, Azure

Senior Manager and Architect, Technical Team Lead, Project Manager, Division Lead, and Founder

2008 - 2015
Grape Solutions Zrt.
  • Led various projects with team sizes between three and ten people, also participating in the development (architecture, POC, and pilot implementations).
  • Managed multiple projects between €10,000 and €200,000 (50 – 600 MD). Also managed delivery, leading the international/Hungarian development division of 35 people.
  • Provided technical expertise on Microsoft BI. Supported presales, prepared demos and workshops, and worked closely with the experts of Microsoft Hungary on pilot implementations.
  • Oversaw the development of technically challenging projects and pilot implementations, such as creating an Excel-like spreadsheet component for a financial planning system in jQuery or optimizing a highly distributed system with SOA architecture.
Technologies: Visual Studio Tools for Office (VSTO), Power View, Power Query, Power Pivot, WWF, SharePoint, Entity Framework, ASP.NET Identity, MSMQ, Microsoft Power BI, SQL Server Reporting Services (SSRS), SQL Server Integration Services (SSIS), SSAS Tabular, SSAS, Microsoft SQL Server, Windows Communication Foundation (WCF), Windows Presentation Foundation (WPF), Model View Controller (MVC), ASP.NET, jQuery, AngularJS, TypeScript, Angular, Azure

Technical Team Lead and Software Architect

2005 - 2008
Cambridge Technology Partners
  • Led offshore projects with team sizes between three and six people, contributing to the development as well. Worked for Swiss FMCG and Swatch maker clients and EU organizations.
  • Provided remote delivery support and maintenance services to operation teams.
  • Designed enterprise-grade solutions for architecture and design guidelines, patterns, and practices. Integrated with heterogeneous back-end systems.
  • Ensured quality during implementation through code reviews, testing, interviews, creation of coding guidelines and best practices documents, maintenance of internal codebase and wiki site, and mentoring of developers.
Technologies: SharePoint, XSD, XML, SOAP, Web Services, Microsoft SQL Server, CSS, HTML, JavaScript, ASP.NET

Lead Developer and Software Architect

2003 - 2005
UNITIS Rendszerház Rt.
  • Worked on a container tracking system for a transportation company. Analyzed the requirements and created functional requirement documents.
  • Created and maintained project plans, WBS, and estimations.
  • Provided technical design, technical planning, and documentation.
  • Led the implementation of the project as a technical lead of a four-person team, participating in the implementation.
Technologies: Crystal Reports, Windows Forms (WinForms), Remoting, .NET, Microsoft SQL Server, CSS, HTML, JavaScript, ASP.NET

Lead Developer

2000 - 2002
GlobeNet Kft.
  • Built a desktop application, a financial module for an ERP system for hospitals (Borland Delphi 4).
  • Developed stored procedures, scripts, and triggers in Oracle PL/SQL. Implemented a transparent, field-level detailed versioning system in the database.
  • Analyzed the requirements during client interviews.
  • Planned and led the implementation of the project as a technical lead for a team of three. Participated in the implementation.
  • Deployed into test and production environments, providing "hypercare" support for the UAT as well as support and maintenance services.
  • Developed reports using Crystal Reports and ReportBuilder for Delphi.
Technologies: Crystal Reports, Oracle RDBMS, Delphi, Database Design, Database Development, SQL Triggers

Part-time Developer

1997 - 2000
Hungarian Ministry of Education
  • Developed the desktop application for a downloadable product that supports filling offline questionnaires with validation, cross-checks, printing, and submission functionalities (Borland Delphi 3).
  • Architected server-side processing logic for the submitted questionnaires, including validation and reporting.
  • Worked with SQL Server 7 and 2000, writing queries and T-SQL procedures.
  • Worked remotely and on-site according to client needs.
  • Provided support and maintenance for the applications.
  • Created user manual and technical documentation for the application.
  • Developed reports in Microsoft Access and generated static HTML reports.
Technologies: Microsoft SQL Server, Visual Basic for Applications (VBA), Microsoft Access, Delphi, HTML, CSS, Database Architecture, Database Design, Database Development, T-SQL (Transact-SQL), Stored Procedure, SQL Stored Procedures

Part-time Developer

1997 - 2000
4DSoft
  • Developed a desktop application for a transport planning system for a gas industry company (Borland Delphi 3).
  • Worked with Oracle RDBMS, creating PL/SQL procedures.
  • Organized my work remotely without management supervision, communicating issues, respecting deadlines, and presenting deliverables weekly or biweekly.
  • Made implementation decisions about functional requirements.
Technologies: Oracle RDBMS, Delphi, PL/SQL, Desktop App Development, Oracle SQL Developer

Commonwealth Portals Development and Support

https://www.commonwealth.com/
Worked on the public-facing and internal portals of Commonwealth Financial Network as a senior full-stack developer integrated into the team of front-end, back-end, and database developers, designers, testers, and managers.

I provided support for many site features, including OpenText CMS pages and ASP.NET legacy forms. I developed a React component library and React forms application to replace legacy forms. I also helped refactor, rewrite, and optimize the existing legacy codebase. I participated in code reviews and technical design decisions and mentored junior developers.

CLIENT
Commonwealth Financial Network (US)

MY ROLE
Front-end developer

TECHNOLOGIES
React, React Hook Form, React Query, TypeScript, styled-components, Storybook, ASP.NET, .NET Framework, jQuery, SQL Server

TOOLS
Azure DevOps, TFS, Git, Jira, OpenText.

Elemy Portals

https://www.elemy.com
Worked on the public-facing and internal portals of Elemy (former Sprout Therapy) as a senior front-end developer integrated into the international team of front-end, back-end, and database developers, designers, testers, and managers (US, Canada, Ukraine).

I implemented many site features, including several workflow solutions and a generic workflow component that separates the workflow definition, logic, and metadata from the presentation. The "Sign-up Flow" is publicly available at Elemy.com/parent-booking. I helped in the refactoring, rewriting, and optimizing of the existing legacy codebase and participated in code reviews and technical design sessions.

Client: Elemy (US)

Role: Front-end developer

Technologies: React, Redux, React Hook Form, React Query, GraphQL, TypeScript, Jest, styled-components

Tools: Spinnaker, Launch Darkly, Figma, Jira

Visual Annotation Tool

Implemented a visual annotation tool in React to manually process camera feeds for fish farms. React Hooks, HTML5, Konva, Open CV, and React-three were used for image processing and to render 2D and 3D visualization. Rendering was optimized to avoid performance issues when working with hundreds of annotations. The tool supports pan and zoom, selection, highlighting, drag and drop, and undo/redo functionalities to work with visual elements. The Keycloak-js library was used for authentication. Integration and E2E tests were implemented using Jest/Enzyme. Back-end services were mocked for E2E tests.

Client: BioSort AS (Oslo, Norway)

Role: Front-end developer, UX designer

Technologies: React, Redux, Redux-saga, TypeScript, Material-UI, Axios, REST, HTML5, Jest/Enzyme, React-Konva, Opencv-ts, React-three

Logistics Application Wizard

Worked on the HTML5 wizard-like user interface of a logistics application for a startup company as a front-end developer. The React SPA wizard heavily utilizes the HTML5 canvas component to provide seamless visualization and interaction when working with thousands of items (like drag-and-drop, undo/redo, zooming, selecting, highlighting, resizing, moving, rotating, and copy-pasting items).

Client: International logistics startup company (full-time remote job)

Role: Front-end developer, UX designer

Technologies: React, Redux, Redux-Saga, TypeScript, Material-UI, Axios, Rest, HTML5, Selenium, Nightwatch

Startup Company Homepage

Served as a front-end developer on the pixel-perfect reactive implementation of a new product's homepage and contact page for a startup company in React and TypeScript. The implementation generates eight breakpoints using SCSS to support two different layouts—mobile and desktop—from 240px to 1980px screen width and all major browsers, including IE11.

Client: A startup company

Role: Front-end developer

Technologies: React, TypeScript, Material-UI, Sass, Axios, and REST

Drilling Location Request System

Contributed to developing a new React-Redux single-page application as a senior full-stack developer and architect using .NET Core, React, TypeScript, and Azure. The application provided the possibility of drilling request creation for users and contained an approval workflow. It contained a complex form with many tabs and collapsible expanders; therefore, React updates and Redux-form state change optimizations were key. I migrated components from the client's non-SPA design framework to React and implemented Excel import functionality using the Open XML SDK. I implemented complex components from scratch (Typeahead, FileUpload for large attachments, formatted DMS input for geographical coordinates), cross-browser support (IE11), and a reactive user interface.

Client: One of the world's largest publicly traded international oil and gas companies (Toptal client)

Role: Full-stack developer, software architect, UX designer

Technologies: React, Redux, Redux-saga, Redux-form, TypeScript, Sass, Jest, Enzyme, .Net Core, xUnit, OpenXml SDK, REST Web API, Axios

Azure services: App Services, Active Directory (OAuth2/OIDC), SQL Server, Graph, Application Insights, Cosmos DB, DevOps, Blob Storage

Tenancy Application

Worked on a new React-Redux tenancy SPA from scratch as a front-end developer using React, Redux, and TypeScript. Scrum and CD/CI were used, and 80% of test coverage was achieved.

Client: Australian startup company (Melbourne)

Role: Front-end developer

Technologies: React, Redux, Redux-saga, Redux-form, TypeScript, Material-UI, Axios, Jest, and Enzyme

Tenancy Application TypeScript Migration

Helped with the migration of a single-page web app from JavaScript to TypeScript, enriching the codebase with models and typed services. Migrated around 300 files in 1.5MB within four weeks with minimal errors. I also provided technical expertise to the offshore team.

Client: Australian startup company (Melbourne)

Role: Front-end developer, TypeScript expert

Technologies: ASP.NET MVC Razor, custom SPA framework, Framework7, TypeScript, and jQuery

Work Safety Conditions Assessment

A mobile-targeted web application (SPA/PWA) for field workers to assess work safety conditions and processes using their devices. The job includes back-end development, mobile UX development, CSS animations, and HTML5 image processing camera pictures.

CLIENT
XTO Energy (Toptal client)

ROLE
Full-stack developer

TECHNOLOGIES
Blazor WebAssembly, Blazor Fluxor, Sass, CSS animations, HTML5, TypeScript, .NET Core

Azure services: Active Directory (OAuth 2/OIDC, B2C), App Service, Blob storage, Cosmos DB, Application Insights, Google Analytics, DevOps, Azure AD B2C

Camera Feed Feature Detection

The purpose of the application is to process images sent by Edge devices to an Azure function by using Azure's custom vision API. Tagged images are saved into blob storage, while meta-data is saved into a Cosmos database. Users can view the camera feeds in a streaming player or by individual images. Events and email/SMS notifications are generated based on user subscriptions and user profile preferences. Active Directory authentication and role-based authorization are used. Managed service identities are used to connect to resources. All keys are stored in a key vault.

Role: Full-stack developer

Client: One of the world's largest publicly traded international oil and gas companies (Toptal client).

Technologies: Angular 7, NgRx/store, NgRx/effects, Ngx-bootstrap components, Sass, Jasmine, Karma, .Net Core, xUnit

Azure services: Active Directory (OAuth 2/OIDC), App Services, Web Jobs, Function Apps, Blob Storage, Cosmos DB, Key Vault, Custom Vision, DevOps

EIT Business Planning System

The purpose of the system is to facilitate the preparation of the KIC business plans and budgets by clarifying the requirements in terms of structure, content, level of detail, and categories of information; the nature and scope of information to be provided for KIC added value activities; and KIC complementary activities.

The SharePoint OOB user interface has been replaced with a custom-developed UI which satisfied usability requirements for structured input of meta-data, in-place editing for multiple rows simultaneously, easy input of budget line hierarchy, validation of in-place edited meta-data on-the-fly, on-the-fly evaluation of formulas for cost tables during structured input, easy selection, and multiple selections during in-place editing of referenced items.

Client: European Institute of Innovation and Technology (Grape Solutions' client)

Role: Full-stack developer and software architect

Technologies: Angular 4, TypeScript, RxJS, Bootstrap, .Net, SharePoint 2013, and SQL Server

Azure Public Cloud Access Management Portal

Contributed to an Azure MVC Razor architecture pilot implementation, creating Azure AD users and subscriptions programmatically for end-users after successfully approving a workflow. The project contains unit tests with silent login, dashboards (Application Insights telemetry), and a single-click deployment package (Azure PowerShell).

Client: One of the world's largest publicly traded international oil and gas companies. (Toptal client)

Role: Full-stack developer and software architect

Technologies: ASP.NET Core MVC Razor, jQuery, Bootstrap, .Net Core

Azure services: App Services, Active Directory (OAuth 2/OIDC), SQL Server, AD Graph, Graph, Application Insights, and PowerShell

Advisory Planning System

Advisory Planning is used by the client’s advisers and agencies for their detailed annual income and strength planning and reporting. The implemented spreadsheet component calculates the formulas on the fly and can be used from any popular web browser. The calculation engine also supports the backward propagation of modified summary values. The solution has a layered and distributed architecture with the front end deployed into the DMZ and the back end put behind the firewall accessible through web services.

I replaced the previous Excel-based FPA solution used by 3000+.

Client: Hungarian branch of Generali Group (Grape Solutions' client)

Role: Technical team lead and software architect

Technologies: ASP.NET, Html, CSS, jQuery, SQL Server, SSRS, and Web Services.

Test Automation Tool Developer

Worked on the unique and innovative in-house test automation framework software pilot of the company for the currently unsupported technical stack using Selenium WebDriver and Appium WebDriver.

Client: Testifi GmbH (Munich, Germany)

Role: Full-stack developer

Technologies: .Net Core, Selenium, Appium, Selenium WebDriver API, XPath, PdfSharp

Customer Approval System

CAS is used by customs officers and travelers worldwide at many exit points at different airports (Singapore, Finland, Jordan) for supporting the VAT refund process for tax-free shopping.

The SOA-based system identifies travelers by credit cards, passports, or bar codes on invoices, and validates the bought products for a VAT refund. The approval transaction is digitally stamped by customs.

The system contains a very complicated and comprehensive rules-based validation engine for country-dependent legal validation, black/white list validation, and random rejection for which parameters can be scheduled depending on the time of the day. The system complies with very strict performance and security measurements (PCI-DSS, PKI, transport-level security).

Client: Global Blue (Grape Solutions' client)

Role: Technical team lead, software architect, project manager

Technologies: WPF, WCF, MSMQ, SQL Server, PCI-DSS, Smartcard/PKI, SOA

Surgery Dashboard Power BI to Tableau Migration, Data Mart Design and Implementation

Owned the migration of a Power BI solution to Tableau using Azure SQL Database and Data Factory. I designed and implemented staging and DWH databases (data mart) and ETL processes. Additionally, I deployed the Tableau Server into Azure and configured Azure Active Directory SAML single sign-on. I also implemented the ETL process using the Azure Data Factory and logic apps for SFTP files.

CLIENT
Healthcare startup company in Massachusetts (Toptal client)

MY ROLE
BI developer

TECHNOLOGIES
Power BI, Tableau, SQL Server, Azure Virtual Machines, Azure Active Directory, SAML single sign-on, Azure Data Factory, and Azure Logic Apps

EIT BI

The goal of the EIT BI project was to integrate all data from the previous projects and custom data from numerous Excel spreadsheets into a single data warehouse and analytical database to provide self-service functionalities for the users for the whole authoring process from data extraction, analysis, aggregation, and custom expression calculation to data model building. The project also included data cleansing and sanitization tasks.

Client: European Institute of Innovation and Technology (Grape Solutions' client)

Role: Technical team lead and project manager

Technologies: SQL Server, SSAS MOLAP, SSIS, Excel, Power Pivot, Power Query, Power View, and SharePoint Excel Services.

MediVIR BI Solution for Hospitals

Led the analysis, design, and implementation of a Microsoft BI product initially developed for the Uzsoki Hospital, which provides monitoring capabilities on a daily basis for the top management of the institution.

Using such a rapidly loaded monitoring tool, the hospital achieved a 2 – 4% cost savings on its budget.

The solution is based on SQL Server BI and Excel dashboards to provide users with eye-catching dashboards with slicers, drill-down capabilities, geospatial visualization, and self-service BI functionalities, not only for the presentation of the data but for the whole authoring process, including extraction, analysis, aggregation, custom expression calculation, and data model building.

CLIENT
Uzsoki Hospital (Grape Solutions' client)

MY ROLE
Technical team lead, software architect, and project manager

TECHNOLOGIES
SQL Server, SSAS MOLAP, SSIS, Excel, Power Pivot, Power Query, and Power View.
1995 - 2002

Master of Science Degree in Computer Science

Eötvös Loránd University, Faculty of Science - Budapest, Hungary

MAY 2024 - PRESENT

AZ-900: Microsoft Azure Fundamentals

Microsoft

JANUARY 2015 - PRESENT

MCP 70-467 - Designing Business Intelligence Solutions with Microsoft SQL Server

Training360 Kft.

DECEMBER 2014 - PRESENT

MCP 70-466 - Implementing Data Models and Reports with Microsoft SQL Server

Training360 Kft.

JANUARY 2011 - PRESENT

MCP 70-576 - PRO: Designing and Developing Microsoft SharePoint 2010 Applications

TrainerC

JANUARY 2011 - PRESENT

MCP 70-573 - TS: Microsoft SharePoint 2010, Application Development

TrainerC

JANUARY 2009 - PRESENT

MCP 70-541 - TS: Microsoft Windows® SharePoint Services 3.0 – Application Development

CONTROLLTraining

JULY 2008 - PRESENT

MCP 70-542 - TS: Microsoft Office SharePoint Server 2007 - Application Development

CONTROLLTraining

JUNE 2008 - PRESENT

MCP 70-547 - PRO: Designing and Developing Web-Based Applications by Using the Microsoft .NET Framework

CONTROLLTraining

MAY 2008 - PRESENT

MCP 70-536 - TS: Microsoft .NET Framework 2.0 - Application Development Foundation

CONTROLLTraining

MAY 2008 - PRESENT

MCP 70-528 - TS: Microsoft .NET Framework 2.0 - Web-Based Client Development

CONTROLLTraining

Libraries/APIs

React Redux, jQuery, React, Redux-Saga, Redux Form, HTML5 Canvas, Entity Framework, Web API, Azure Blob Storage API, Azure Active Directory Graph API, Windows Forms (WinForms), Vue, NgRx, NgRx/store, RxJS, React Query, React Hook Form, Vue 2, REST APIs, Nightwatch.js, Google Analytics API, Selenium WebDriver, Selenium API, PDFSharp, Konva, OpenCV, WebDriver

Tools

Azure App Service, Microsoft Project, Visual Studio Tools for Office (VSTO), C#.NET WinForms, SQL Server BI, SSAS, Microsoft Visual Studio, Microsoft Access, Git, Redux Thunk, Azure Application Insights, xUnit, Azure DevOps Services, Microsoft Power BI, Power Pivot, Power Query, Power View, PM2, Tableau, Tableau Desktop Pro, Azure Logic Apps, xUnit.net, Visual Studio, Crystal Reports, SQL BI Development Studio, Microsoft Graph, Karma, Azure Key Vault, Azure Active Directory B2C (ADB2C), Blender, Keycloak, LaunchDarkly, Figma, Jira, TFS

Frameworks

Blazor, ASP.NET Core, ASP.NET Core MVC, Bootstrap, .NET Core, ASP.NET MVC, .NET, ASP.NET, ASP.NET Identity, ASP.NET Web Forms, Redux, Material UI, Unity, Razor, Razor Pages, MVC Razor, OAuth 2, Windows PowerShell, ASP.NET Web API, Unity3D, Windows Presentation Foundation (WPF), AngularJS, Jest, WWF, Jasmine, Angular, Selenium, .NET 4, Appium

Languages

XML, Visual Basic .NET (VB.NET), C#.NET, CSS, JavaScript, HTML, T-SQL (Transact-SQL), ASP.NET Razor, TypeScript, Sass, MDX, XSD, HTML5, GraphQL, Delphi, Visual Basic for Applications (VBA), SAML, XPath, Stored Procedure, C#

Paradigms

Enterprise Application Architecture, Scrum, Design Patterns, Waterfall Development, ETL Implementation & Design, REST, OLAP, Functional Analysis, Agile Software Development, Continuous Integration (CI), Continuous Delivery (CD), Model View Controller (MVC), Service-oriented Architecture (SOA), Azure DevOps, Desktop App Development, Database Design, Database Development

Platforms

Microsoft BI Stack, Azure, Azure Functions, Visual Studio Code (VS Code), SharePoint, Spinnaker

Storage

Azure Websites, Azure SQL, Azure SQL Databases, Microsoft SQL Server, JSON, SQL Server Reporting Services (SSRS), Azure Active Directory, SSAS Tabular, SQL Server Integration Services (SSIS), Azure Cosmos DB, Azure Blobs, Oracle RDBMS, SQL Server 2012, SQL Server Analysis Services (SSAS), PL/SQL, Oracle SQL Developer, Database Architecture, SQL Stored Procedures, SQL Triggers

Industry Expertise

Project Management

Other

Axios, User Experience (UX), Web UX, Microsoft Graph API, Enterprise, Microsoft Certified Professional Developer (MCPD), Pivot Tables, Apps, Data Warehouse Design, Technical Design, Project Planning, Software Architecture, Enterprise Architecture, Web Services, Microsoft 365, Microsoft Azure, Web Applications, Web UI, WebAssembly, OAuth, Query Optimization, DOM, Functional Design, Web App UX, Functional Specifications, DAX, Algorithms, Multidimensional Expressions (MDX), WCF Web Services, SOAP, Enzyme, Tableau Server, Azure Data Factory, Remoting, Windows Communication Foundation (WCF), MSMQ, SSRS Reports, Microsoft Data Transformation Services (now SSIS), XML Web Services, SFTP, SAML-auth, Power Shell Commands, SDKs, Azure WebJobs, Azure AI Custom Vision, Progressive Web Applications (PWA), CSS3 Animation, PCI DSS, Microsoft Project Server, Styled-components, Workflow, UI Components, APIs, Storybook, OpenText

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