Allabi Yanness, Developer in Paris, France
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Allabi Yanness

Verified Expert  in Engineering

Full-stack Developer

Paris, France
Toptal Member Since
August 15, 2022

Yanness is a highly skilled full-stack developer with over eight years of experience building applications in the finance, education, and healthcare industries. While primarily focusing on the .NET stack, Yanness started working in React two years ago and now considers it one of his top skills. He has developed platforms, spearheaded complex applications, migrated products, and mentored junior team members. Yanness is interested in working on challenging projects and furthering his career.


Groupe Credit Agricole
C#.NET, ASP.NET, .NET Core, Domain-driven Design (DDD), CQRS, Event Sourcing...
PHP, Java, HTML5, MySQL, JavaScript, Spring Boot, SQL, Full-stack, HTML, CSS...
Talents Consulting
Java, Jira REST API, Jira, Angular, Spring Boot, C#.NET WinForms, Thymeleaf...




Preferred Environment

.NET Core, React, Microsoft SQL Server, Octopus Deploy, Azure DevOps, SignalR, Event Sourcing, CQRS, Domain-driven Design (DDD), Docker, .NET, ASP.NET Core

The most amazing...

...thing I've developed is a workflow builder and processor, which is used by financial institutions to automate business processes.

Work Experience

Senior Full-stack .NET and JavaScript Developer

2020 - PRESENT
Groupe Credit Agricole
  • Contributed to the customer relationship management software by improving the compliance module and helping the compliance management identify conflicts of interest and trace customers' activities.
  • Migrated the Angular UI code to React and designed new React UI components.
  • Maintained and upgraded part of the legacy code written in .NET, ASP.NET MVC 4, and ASP.NET Web Forms. The maintenance included fixing issues with the shared library code, CQRS, event sourcing, and the internal IoC container.
  • Collaborated with the business team on implementing new requirements, improvements in domain logic, UI updates, performance optimizations, API updates, and refactoring.
  • Debugged business logic and technical defect issues.
  • Deployed hotfixes and releases using Azure Pipelines and Octopus Deploy.
Technologies: C#.NET, ASP.NET, .NET Core, Domain-driven Design (DDD), CQRS, Event Sourcing, Angular, React, Cypress, Kibana, .NET, SQL, APIs, REST APIs, Full-stack, JSON Web Tokens (JWT), SQL Server 2017, HTML, CSS, C#, LINQ, Razor, MVC Razor, Microsoft Unit Tests, Integration Testing, Agile, AngularJS, Azure, .NET 6, Microsoft Azure, Bootstrap, ASP.NET Core MVC, API Integration, Windows Services, XML, Object-oriented Programming (OOP), XSD, Serializer/Deserializer (SerDes), Architecture, Application Architecture, IIS, Legacy Software, ASP.NET Core, Windows Server, Finance, ASP.NET MVC, Visual Studio, Google Sheets, REST, Software Engineering, CI/CD Pipelines, Razor Pages, Unit Testing, RESTful Microservices, .NET 4, WCF Web Services, Single Sign-on (SSO), Integration, Entity Framework Core, Microsoft Teams, Entity Framework, TypeScript, Microsoft Visual Studio, Front-end, OAuth, RESTful Services, Moq, Fluent Assertions, NUnit, Software Development Lifecycle (SDLC), Back-end, MediatR, .NET 2

Technical Consultant | Data Analyst and Freelance Java, Spring, and PHP Developer

2020 - 2021
  • Developed a web-based data collection and visualization system for the digital transformation of local agricultural production monitoring. The system includes tools for reporting, statistics, and a custom workflow engine for habilitation management.
  • Created a web-based document management system that helps users classify documents and publish them to groups of users based on configurable habilitations.
  • Monitored system logs and provided data regulation support.
Technologies: PHP, Java, HTML5, MySQL, JavaScript, Spring Boot, SQL, Full-stack, HTML, CSS, Spring, Architecture, Bootstrap, API Integration, Apache, LAMP, Object-oriented Programming (OOP), Application Architecture, IIS, Visual Studio, Google Sheets, REST, RESTful Microservices, Integration, Microsoft Teams, Entity Framework, Front-end, Software Development Lifecycle (SDLC), Back-end

Senior Consultant | Java and Jira Developer

2017 - 2019
Talents Consulting
  • Served as a lead architect on business process automation projects, including working on workflow automation, optimizing and designing business process models using Lean Six Sigma, and implementing models in web-based applications.
  • Led a team of seven programmers with various skills and provided training on coding standards, tools, and business process management modelization techniques.
  • Estimated, planned, and tracked development efforts and product deliveries across the development team.
  • Organized workshops with clients, modeled business processes according to defined needs, and estimated delivery dates and costs.
  • Developed bootstrap templates for workflow-oriented web applications so that developers can focus on implementing business logic.
  • Wrote and maintained technical and functional specifications for projects.
Technologies: Java, Jira REST API, Jira, Angular, Spring Boot, C#.NET WinForms, Thymeleaf, JavaScript, .NET, SQL, APIs, REST APIs, Full-stack, SQL Server 2017, HTML, CSS, C#, Microservices, Agile, AngularJS, Spring, Bootstrap, ASP.NET Core MVC, API Integration, Apache, LAMP, Object-oriented Programming (OOP), Architecture, Application Architecture, IIS, Web Services Description Language (WSDL), Windows Server, SOAP, Finance, ASP.NET, ASP.NET MVC, C++, Google Sheets, REST, Software Engineering, CI/CD Pipelines, GitHub, Razor Pages, Unit Testing, RESTful Microservices, .NET 4, Integration, Applicant Tracking Software (ATS), Stripe API, Stripe, Stripe Connect, Microsoft Teams, Oracle Database, TypeScript, Microsoft Visual Studio, Front-end, Amazon Web Services (AWS), RESTful Services, NUnit, Software Development Lifecycle (SDLC), AWS Lambda, Node.js, Amazon Aurora, Back-end

IT Officer

2014 - 2017
First Bank of Nigeria
  • Managed databases for security issues, updates, and upgrades using ETL, Oracle, and the SQL Server.
  • Designed and developed third-party applications linked to the core banking system that cover e-statements, SMS banking, and the bank clearing system.
  • Built a card request processing system that reduces card delivery time from one month to two weeks. The system has an interface that records and processes customer requests, sends card request details to the editing system, and tracks card delivery.
  • Developed an automated reporting platform used by all bank customer relationship managers, allowing them to generate and send KPIs, compliance, central bank, and group reports from the web interface in a few clicks.
  • Provided the core banking Finacle users with support for applications used by the bank, such as SICA-UEMOA and UAP bank clearing applications.
  • Contributed to the migration of the core banking system from Delta to Finacle as a subject matter expert.
Technologies: Oracle, Finacle, C#.NET WinForms, PHP, Red Hat Linux, Oracle 10g, Oracle 11g, .NET, SQL, HTML, CSS, C#, Bootstrap, API Integration, Apache, LAMP, XML, Object-oriented Programming (OOP), XSD, Serializer/Deserializer (SerDes), Full-stack, Windows Server, Finance, ASP.NET, ASP.NET MVC, Visual Studio, Google Sheets, REST, Software Engineering, Razor Pages, RESTful Microservices, WCF Web Services, Integration, Entity Framework Core, Entity Framework, Oracle Database, Microsoft Visual Studio, Front-end, RESTful Services, Software Development Lifecycle (SDLC), Back-end

Compliance Module

Migrated the product from ASP.NET MVC to .NET Core, revising the architecture from basic CRUD to a domain-driven design with command query responsibility segregation and event sourcing.

The migration consisted of moving the compliance activities functionality from the CRM to a .NET REST API. Some of the UI was moved from ASP.NET Razor and web form components to React web components to be merged with the existing UI.

I wrote the data denormalization code, which maintained consistency between the read SQL Server database and the write Event Store database. Also, I developed React components and wrote unit and integration tests using and user interface tests using Cypress.

Health Checks Dashboard

Built a React-based dashboard supported by a .NET Core REST API. The dashboard shows the availability status of all applications related to the CRM platform and their dependencies, in addition to reporting the latest error logs to Kibana.

The dependencies are SignalR links to other applications, database connections, or Event Store connections. The availability percentage is calculated based on specific rules, and alerts are sent when predefined thresholds are reached. For the dashboard to retrieve the necessary data, each application must expose a dedicated endpoint wrapped with a shared library, leaving the application team only to implement the health check logic.

Monetary Transaction Clearing

Created REST Spring Boot API that allows transfers from bank accounts to digital wallets by performing internal account settlements.

The API receives the settlement data in JSON with a specific accounting schema and checks invariants. Once the accounts are opened, the right balance is available, and the settlements are processed using the core banking system's SOAP API or by integrating an ISO 20022 XML file.

Supply Management Software

Contributed to the project by working on the back end, front end, and software architecture and built the application based on Spring Boot and Jira Core.

The application allowed companies' purchasing departments to notify suppliers and manage a supplier database, including referencing and contract management. The software follows order processing, from initialization to product delivery. The platform includes automatic supplier pricing, invoice management, payment modules, and an integrated calendar that is synced with the company's email system.

I designed the plugin-oriented software using a microservices architecture with a front-end gateway that handles rendering and authentication. The gateway was built using Angular, and the back-end microservices were implemented with Spring Boot and interacted with the Jira Core engine using REST API. Additionally, I implemented the internal workflows, such as the approval request flow, interest call management, and order fulfillment management.

Interbank Payment Reconciliation and Card Management Suite

Developed a suite of applications to manage clearing, interbank payment reconciliation, and credit card application processing, and worked on visualization and reporting for service-level agreement application processing.

The suite included tools for extracting compressed JPEG bank checks, managing rejected transfers and checks, and allowing semi-automatic fund transfers. The applications handled money-clearing files integration, allowed the ATM and POS transaction accounting, and used an XML model for data mapping. To manage and process bank card requests, the applications generated and integrated card creation files in compliance with PCI DSS standards.

Data Collect andd Visualization Platform - Monitoring
This application is written entirely in PHP from scratch with an MVC design. It was developed for an NGO that wanted to automate its process of collecting and analyzing local agricultural data to identify the impact of their actions in the context of global agricultural development aid in third-world countries.

Its objective was to provide users with a user interface to enter agricultural production data remotely. Once data is submitted through HTML forms, a validation flow is triggered where users with higher permissions confirm (or reject) the entries. Once everything is validated, statistics are generated and displayed in the user interface as HTML tables or Chart.js charts, with a filter to select the required geographical area or period. Statistics can also be exported in CSV/Excel. The second objective of the application was to provide an election document management system where supporting documentation is made available to local agricultural actors.

I was the only developer on this project, and I built both the front-end and the back-end and deployed the application on a CentOS base VPS with Apache (httpd) as a web server and MySQL as a database system.

Timesheet Management Web App

I collaborated as a full-stack developer with the CTO, who acted as the product owner, to define the functional and technical specifications for a web application based on .NET Core.

The application's back end was built using .NET Core 6 Web API, along with .NET background tasks and Hangfire jobs. The front end was developed as a React single-page application (SPA). SQL Server 2014 served as the chosen database server.

To integrate with external systems, the new platform was designed to interact with Fieldpoint via the SOAP protocol. This integration facilitated the consumption of employee time information. Additionally, the application communicated with Business Central by generating CSV files that could be used for payroll processing.

During the project, I undertook a complete overhaul of the user interface (UI), introducing modern components. Furthermore, I incorporated a validation workflow that generates email notifications based on configurable rules.


Entity Framework, REST APIs, React, Jira REST API, jQuery, LINQ, Moq, MediatR, SignalR, iTextSharp, Stripe API, Stripe, Stripe Connect, Node.js


Jira, Google Sheets, Microsoft Visual Studio, Microsoft Unit Tests, Visual Studio, Microsoft Teams, Kibana, C#.NET WinForms, Finacle, Oracle Data Access Components (ODAC), Apache, Dapper, GitHub


.NET Core, ASP.NET, .NET, ASP.NET Core, Entity Framework Core, Angular, JSON Web Tokens (JWT), Razor, MVC Razor, Spring, Bootstrap, ASP.NET Core MVC, ASP.NET MVC, Razor Pages, .NET 4, NUnit, .NET 2, Cypress, Spring Boot, Thymeleaf, Spring Microservice, AngularJS


C#.NET, Java, PHP, SQL, C#, JavaScript, HTML5, HTML, CSS, XSD, Web Services Description Language (WSDL), TypeScript, XML, XPath, CSS3, C++


Object-oriented Programming (OOP), Application Architecture, REST, CQRS, Microservices, Agile, Unit Testing, Azure DevOps, Event Sourcing


Oracle Database, Oracle, LAMP, Windows Server, Amazon Web Services (AWS), Docker, Red Hat Linux, Windows, Azure, Linux, AWS Lambda


Microsoft SQL Server, MySQL, SQL Server 2017, PostgreSQL, SQL Server 2014, Neo4j, Web Forms, Oracle 10g, Oracle 11g, Amazon Aurora


APIs, Full-stack, Architecture, API Integration, Integration, Front-end, Back-end, Domain-driven Design (DDD), Integration Testing, Windows Services, Serializer/Deserializer (SerDes), IIS, Legacy Software, SOAP, Software Engineering, RESTful Microservices, WCF Web Services, OAuth, RESTful Services, Fluent Assertions, Software Development Lifecycle (SDLC), Octopus Deploy, Amplitude, Web Components, Windows Communication Foundation (WCF), .NET 6, Microsoft Azure, CSV File Processing, Finance, CI/CD Pipelines, Single Sign-on (SSO), Applicant Tracking Software (ATS)

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