MARGO

Regular .NET Developer (Card Payment Systems)

Posted 15 Days Ago

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Hiring Remotely in Warsaw, Warszawa, Mazowieckie

In-Office or Remote

Mid level

Information Technology • Consulting

The Role

The role involves developing and maintaining core card payment systems, optimizing applications, and collaborating in Agile teams to enhance functionality and performance.

Summary Generated by Built In

About the role

We are looking for a Regular .NET Developer to join a team responsible for developing and maintaining core card payment systems - from transaction authorization and settlement to integrations with external payment services.

The systems process hundreds of thousands of transactions daily, so performance, availability and security are key priorities.

Work model: Remote-first with scheduled on-site team meetings (2 days per month in Warsaw).

Responsibilities

- Develop and maintain .NET applications in card payment domain

- Design and implement new functionalities according to business and regulatory requirements

- Integrate systems with external services (REST, SOAP, messaging queues)

- Optimize performance, availability and security of applications

- Cooperate with Analysts, Architects and QA in Agile/Scrum teams

- Participate in SIT/UAT testing, code reviews and preparation of technical documentation

Required skills

- Commercial experience with C# and .NET (Framework / Core)

- Experience with ASP.NET Core, Angular and WebAPI

- Knowledge of Entity Framework, LINQ, Dapper

- Experience with SQL Server (T-SQL) and query optimization

- Knowledge of SOLID principles and design patterns

- Experience writing unit tests (xUnit / NUnit)

- Experience with system integrations (REST, SOAP, JSON, XML)

- Experience working in Agile environment

- Knowledge of Git, CI/CD and TeamCity

Language requirements

- Polish: native or C2 level (required)

- English: professional level enabling work with technical documentation

Nice to have

- Experience in card payments / payment processing domain

- Knowledge of Docker / Kubernetes

- Experience working on high-availability or complex distributed systems

Margo Offers:

- B2B cooperation

- Remote working model

- Benefits such as medical care and sports card

- Co-financing trainings, certification exams and post-graduate studies

- Ability to work in an international consulting company on ambitious projects

- Possibility to get involved in outside-project activities with additional remuneration)

- Excellent working atmosphere, integration events

Top Skills

.Net Core

.Net Framework

Angular

Asp.Net Core

Ci/Cd

Dapper

Entity Framework

Git

JSON

Linq

Rest

Soap

Sql Server (T-Sql)

Teamcity

Webapi

XML

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The Company

London

358 Employees

Year Founded: 2005

What We Do

More than a simple IT consulting group, MARGO is an alchemy of talents with constantly enriched expertise, always encouraged to be dynamic and to flourish.

For more than 17 years, we have been carrying out missions of the highest technical complexity, enabling the digital acceleration of our clients, while ensuring a perpetual intellectual and collective stimulation for all our talents.

At MARGO it's Consultant First.

By joining MARGO, your talent today will remain relevant tomorrow. We bring you into the group not only for what you are today but for the potential you wish to develop.

At MARGO, you will be able to build your own path to excellence within our teams and our missions. Tailor-made to serve your ambition and to match your talent.

Today, Margo has over 400 employees in 8 entities:

► MARGO Trading Systems: our full stack development offer in market finance
► MARGO Capital Markets: our business offer in market finance
► MARGO Analytics: our expertise in data science and data engineering
► A CAPELLA Consulting: our business offer dedicated to insurance
► CODE BUSTERS: our community of developers
► DELIVERED by MARGO: our 100% remote full stack development entity
► MARGO UK: expertise in complex coding and application support on the English market.
► MARGO Poland: expertise in complex coding in retail Banking on the Polish market