Cristian Grigoras, Developer in Bucharest, Romania
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Cristian Grigoras

Verified Expert  in Engineering

Full-stack Developer

Bucharest, Romania
Toptal Member Since
May 2, 2022

Cristian is a full-stack developer and software engineer with over eight years of experience in the banking and adtech industry. He focuses on using C#, .NET, and SQL while following the Agile and Kanban methodologies. As a results-oriented professional who is comfortable switching between various architectures and designs, Cristian enjoys challenges and finding innovative solutions that suit the clients' needs.


TBC Bank - Main
C#, .NET, C#.NET, SQL, REST APIs, ASP.NET Identity, IdentityServer 4
Three Five Two, Inc.
.NET, C#.NET, Microsoft SQL Server, AngularJS, C#, Web API, Entity Framework...
Azavar Technologies Corp
C#, .NET, SQL, JSON, XML, Bootstrap




Preferred Environment

MacOS, Visual Studio, .NET Core, PostgreSQL

The most amazing...

...thing I've created is an AI module to compute the complexity of a PDF file to see if it renders on the back end or front end.

Work Experience

.NET Developer

2023 - 2023
TBC Bank - Main
  • Managed to finish work on the library that can be injected for authorization and authentication in any of its microservices.
  • Manage to migrate all routes in the transfer templates area to be used as a proxy to an old system.
  • Created a lot of unit tests for the system in order to keep and get 80% coverage.
Technologies: C#, .NET, C#.NET, SQL, REST APIs, ASP.NET Identity, IdentityServer 4

.NET Full-stack Developer

2022 - 2023
Three Five Two, Inc.
  • Developed a two-factor authentication on a legacy .NET framework project.
  • Added new reports to a .NET project using SQL database and entity framework.
  • Implemented Google Sign-In feature to an existing application.
Technologies: .NET, C#.NET, Microsoft SQL Server, AngularJS, C#, Web API, Entity Framework, Dapper

.NET Developer

2022 - 2022
Azavar Technologies Corp
  • Worked on legacy C# application and developed new features for it. Added new pages for a specific role, secured so that only that role can see them. Added new reports for those roles.
  • Tracked and fixed bugs using Jira as a reporting tool.
  • Developed a new tool in the automation process where you can upload an excel file with addresses to be queried over an API to check the jurisdiction where they belong. Results were also saved to a database for a fast response the next time.
Technologies: C#, .NET, SQL, JSON, XML, Bootstrap

Senior Back-end Engineer

2020 - 2022
Invibes Advertising
  • Contributed to various platforms, such as TCF module, geotagging that connects users with an ad, and a big data service that transforms attributes received from partners.
  • Created a list of users (IDs) with some defined attributes using the Bloom filter algorithm for big lists and HashSet for small ones. Synchronized a list of IDs created by some defined features with the ad server.
  • Merged IDs into the family if they had common identifiers.
  • Contributed to the capping list service that can cap users, write IDs to files from the ad server, read ad event viewer, perform database shard, and create files for IDs.
  • Monitored a suite of services to schedule and run database and Windows scripts and display results on each run.
  • Wrote different scripts such as .NET scripts that needed to run on big DB, scripts to unmerge families of IDs on big sharded DB, scripts to modify attributes given by a particular provider, and scripts to clean only families made by identifiers.
  • Built a new framework in .NET Core and worked on the core SFTP reader, email sender, and encryption.
  • Integrated a test framework, changed communication between two apps from API to WebSocket, bundled enums to JavaScript, and organized workshops for a development team.
Technologies: .NET Core, .NET 5, PostgreSQL, Redis Cache, MySQL, AngularJS, Razor, Blazor, Microservices, Sharding, .NET, Visual Studio, Algorithms, Data Structures, C#, C#.NET, Dapper, CQRS, Entity Framework, Entity Framework Core, Design Patterns, Channels, SFTP, Big Data

Senior Full-stack Developer

2019 - 2020
  • Developed an application to view PDFs and other files online using WebViewer, WOPI protocol, Office 365, and SharePoint.
  • Created an AI module to estimate the complexity of PDF documents through multiple linear regression with continuous learning.
  • Optimized the application to save RAM and modified algorithms and patterns for GC to clean the memory.
Technologies: .NET Core, Docker, Backbone.js, Java, Kotlin, Python, Entity Framework, .NET, Visual Studio, MacOS, MySQL, Microservices, Algorithms, Data Structures, C#, C#.NET, Machine Learning, React

Team Lead

2018 - 2019
Societe Generale
  • Conducted regular meetings with people from the team, guided them, and managed projects between France and Romania.
  • Supervised the eDirectory, a massive database with people worldwide working in SG, all subsidiaries, banks, and every entity involved in the company.
  • Migrated the applications from virtual machines to Docker.
Technologies: Node.js, AngularJS, MongoDB, Elasticsearch, Docker, React, Algorithms, Data Structures

Senior Software Engineer

2015 - 2018
Societe Generale
  • Created a web application where policies could be defined and assigned to a group of users.
  • Built a Windows service that read, parsed, and sent logs to a database and a web application that read the database and displayed the results using a filter feature.
  • Contributed to the AD provisioner and ISO connector projects with an active directory by creating, updating, or deleting different Windows and web services features.
  • Performed mapping and worked on interfaces of CryptoManager—a WPF desktop application to manage crypto certificates from email—to send trades from the XOne system to MarkitWire API.
  • Imported rules from an EMT file used to accept a trade-in MarkitWire.
Technologies: .NET 5, Angular, Windows Presentation Foundation (WPF), .NET, Visual Studio, MySQL, Data Structures, C#, C#.NET

Associate Software Engineer

2014 - 2015
  • Solved bugs in C++ and C# on the back-office servers of Sophis product, optimized algorithms, and debugged using Visual Studio.
  • Acted as the main developer of the STP Omgeo server and developed an email module for the application.
  • Moved the STP Omgeo server from C# hardcoded values to C# combined with XSLT to enable customers to change their values.
Technologies: .NET, MSBuild, Oracle, Visual Studio, Data Structures, C#, C#.NET, C++

Ambiental Intelligence for Android Devices
A platform for communication between Android phones and PCs and intelligence modules.

Artificial intelligence scenarios based on the platform we developed:
• detection of the user's location based on a nearby wireless network
• communication between devices such as laptops, mobile phones, and computers
• detection of ambient noise levels and the users' movements sent to other devices

Tron Bot
An algorithm for a bot in the Tron game that can win every kind of map.

The main idea was to find the inflection points and fill the most significant room. When meeting an opponent, it tries to block it, using a classic minimax algorithm with a heuristic one.

Sync Service

A service synchronizes files between two file handlers, such as system files, FTP, and API.

The service works with three workers; each can have multiple parallel instances—reader, transformer, and writer. Workers communicate using the .NET channel.


C#, C#.NET, C++, Java, Kotlin, Python, SQL, XML


.NET Core, .NET 5, .NET, Entity Framework Core, AngularJS, Razor, Blazor, Angular, Windows Presentation Foundation (WPF), Bootstrap, ASP.NET Identity, IdentityServer 4


Visual Studio, Dapper, MSBuild


Microservices, CQRS, Design Patterns


SFTP, Algorithms, Data Structures, Programming, Sharding, Big Data, Channels, Machine Learning


Entity Framework, Backbone.js, Node.js, React, Web API, REST APIs


PostgreSQL, MySQL, Redis Cache, MongoDB, Elasticsearch, JSON, Microsoft SQL Server


MacOS, Linux, Docker, Oracle

2011 - 2015

Bachelor's Degree in Computer Science

Politehnica University of Bucharest - Bucharest, Romania

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