Senior .NET Developer with WPF and REST APIs, Portfolio Management System

🏢 Summary: The offer is for a Senior .NET Developer responsible for improving and refactoring core backend systems to enhance structure, maintainability, and security. The role focuses on reducing technical debt, enabling automation and AI integration, and ensuring high code quality through testing and CI/CD practices. The position involves hands-on development within legacy or monolithic environments and driving system modernization. 🗂️ Requirements: 5+ years experience in .NET / C# backend development, Experience with legacy or monolithic systems, Strong knowledge of clean code principles, Proven experience in refactoring existing codebases, Strong SQL and backend integration experience, Experience with APIs and service-based architecture, Experience with CI/CD pipelines, Experience with automated testing, Familiarity with TDD or BDD practices, Experience with Gherkin, SpecFlow, Cucumber or similar, Experience using AI tools in development workflows, Understanding of code structuring for automation and AI integration 📃 Skills: .NET, C#, SQL, APIs, CI/CD, TDD, BDD, Gherkin, SpecFlow, Cucumber, AI, Git, Docker, .NETCore 🏢 Description: Introduction & Summary: We are seeking a Senior .NET Developer with 5-8+ years of experience in backend development and .NET engineering. The successful candidate will drive improvement in code quality, reduce technical debt, and support system structuring for better predictability. With a focus on future automation and AI capabilities, you will help ensure code understandability, maintainability, and security. Main Responsibilities: Responsible for hands-on development and refactoring of core systems, with the aim of enhancing their structure and predictability. Develop and improve .NET-based systems. Reduce technical debt and increase maintainability. Support safe and efficient delivery. Ensure code is understandable, maintainable, and secure. Make systems testable and observable. Facilitate automation of workflows. Key Requirements: Strong experience with .NET / C#. Experience working with legacy or monolithic systems. Strong understanding of clean code principles. Experience with refactoring and improving existing codebases. Strong SQL and backend integration experience. Experience with APIs and service-based architecture. Experience with CI/CD pipelines. Experience with automated testing. Familiarity with TDD / BDD and security by design thinking. Experience with Gherkin / SpecFlow / Cucumber or similar. AI-related: Experience using AI tools in development workflows. Understanding of code structuring for automation and AI integration. Experience using AI for debugging, testing, or documentation support. Nice to Have: Experience with .NET Core. Experience with containerization. Exposure to AI-assisted testing or development tools. Experience improving system observability.

🏢 Summary: Senior C#/.NET Developer role focused on building and scaling high-performance backend systems for risk management, XVA, and asset-liability management within the financial domain. The position involves modernizing legacy components into a scalable, event-driven architecture and working across the full software development lifecycle in an agile, distributed team. Strong expertise in distributed systems, DevOps practices, and capital markets risk concepts is required. 🗂️ Requirements: 5+ years enterprise experience with C# and .NET (Web API, asynchronous programming, background services), Strong knowledge of distributed systems and Enterprise Integration Patterns, Experience with message brokers/service buses (e.g., RabbitMQ, MassTransit, Rebus), Solid experience with MS SQL Server or other relational databases, Experience with micro-ORMs (e.g., Dapper), Proficiency with Git-based repositories and CI/CD platforms (Jenkins, TeamCity, GitLab CI), Experience with configuration management tools (e.g., Ansible), Practical exposure to Generative AI / Agentic AI workflows in software engineering, Strong understanding of Capital Markets and derivatives (Listed and OTC), Knowledge of risk management concepts (Greeks, PnL Explain), Understanding of Valuation Adjustments (CVA, FVA) and liquidity/balance sheet metrics 📃 Skills: C#, .NET, ASP.NET, WebAPI, SignalR, RabbitMQ, MassTransit, Rebus, MSQL, Dapper, Git, Bitbucket, Jenkins, TeamCity, Ansible, CI/CD, SQL, XVA, ALM 🏢 Description: We are looking for a Senior C#/.NET Developer with Financial Domain Knowledge. In this role, you will be responsible for designing and scaling high-performance backend systems that support advanced risk management, valuation adjustments (XVA), and asset-liability management (ALM). You will work within a distributed, agile engineering team focused on modernizing legacy components into a highly scalable, event-driven architecture. Key Responsibilities Designing and developing high-performance C#/.NET applications and backend services Building scalable, event-driven and distributed systems in enterprise environments Developing asynchronous communication solutions using messaging frameworks (e.g. Rebus) Working with ASP.NET Web API, Windows Services, and SignalR Applying clean architecture, SOLID principles, and design patterns in daily development Collaborating in Agile teams across international environments Participating in full software development lifecycle, including architecture, implementation, testing, and deployment Working with CI/CD pipelines and DevOps tools such as Git, Bitbucket, Jenkins, TeamCity, and Ansible Optimizing and maintaining MS SQL databases and data-intensive applications Using ORM tools such as Dapper for efficient data access Contributing to code reviews, technical improvements, and engineering best practices Leveraging LLMs and AI-assisted development tools to improve software quality and engineering efficiency Delivering maintainable, scalable, and well-documented solutions under tight deadlines Requirements 5+ years of hands-on experience in enterprise-level software development using C# and the .NET ecosystem (including Web API, asynchronous programming, and background services). Strong command of System Architecture: practical knowledge of distributed systems, Enterprise Integration Patterns, and message brokers/service buses (e.g., RabbitMQ, MassTransit, Rebus or similar). Solid database experience with MS SQL Server (or other relational databases) and micro-ORMs (e.g., Dapper) optimized for high throughput. Proficiency with standard DevOps toolchains: Git-based repositories, modern CI/CD platforms (Jenkins/TeamCity/GitLab CI), and configuration management tools. Practical exposure to Generative AI / Agentic AI workflows applied to software engineering practices. Financial Domain Knowledge (Quantitative & Risk) Solid understanding of Capital Markets, including Listed and OTC derivatives. Familiarity with risk management concepts: Greeks (Delta, Gamma, Vega, Theta) and PnL Explain. Understanding of Valuation Adjustments (XVA) such as CVA, FVA. General awareness of Liquidity Risk, Balance Sheet Metrics, and transactional workflows (pre-trade/booking).

🏢 Summary: B2B opportunity for an experienced .NET Back-End Developer to build modern, scalable cloud-based solutions using C# and Azure. The role focuses on designing high-performance services, working with CosmosDB, and collaborating in an Agile team with exposure to AI-assisted development tools. This is a fully remote position with competitive hourly rates and long-term cooperation. 🗂️ Requirements: 5+ years of professional experience in .NET development, Strong experience with C#, Proven experience with Azure services, Experience with CosmosDB, Experience with TypeScript or JavaScript, Bachelor’s degree in Computer Science or related field, Ability to align with US-based team working hours, English language proficiency 📃 Skills: .NET, C#, Azure, CosmosDB, TypeScript, JavaScript, AI, Playwright, Selenium, Drupal 🏢 Description: For our client from the technology and industrial solutions sector, we are looking for a .NET Back-End Developer to join a talented development team working on modern, scalable software solutions. Responsibilities: Design, develop, and maintain high-performance back-end services using .NET and C#. Work extensively with Azure cloud services and CosmosDB to build scalable and resilient solutions. Collaborate with front-end developers, product owners, and other team members to integrate back-end services. Participate in code reviews, architectural discussions, sprint planning, and other Agile ceremonies. Use modern development tools and practices to improve productivity, code quality, and maintainability. Explore and apply AI-assisted tools where appropriate to support development, documentation, troubleshooting, and workflow efficiency. Contribute to improving development processes, engineering practices, and team knowledge sharing. Be a proactive problem-solver and continuous learner, staying current with relevant technologies and industry trends. Requirements: Application Development Experience: 5+ years of professional experience in .NET development. Cloud Development Expertise: Proven experience with C#, Azure services, and CosmosDB. Scripting / Front-End Knowledge: Experience with TypeScript preferred, or JavaScript. AI Tool Familiarity: Interest in or hands-on experience using AI tools to support software development, productivity, documentation, research, or troubleshooting. Educational Background: Bachelor’s degree in Computer Science or a related field. Flexibility: Ability to align somewhat with US-based team working hours. Communication: English language proficiency. Stack: Cloud: Azure, CosmosDB Back-End: .NET, C# Scripting / Tooling: TypeScript preferred, JavaScript acceptable Productivity / AI Tools: Familiarity with AI-assisted development or productivity tools is a plus Nice to have: Domain Knowledge: Background in Electrical Engineering or a related technical field. Background or interest in analog and mixed-signal hardware design. Knowledge of hardware or system simulation concepts. CMS Knowledge: Familiarity with Drupal. Test Automation Exposure: Familiarity with tools like Playwright or Selenium. Quality Mindset: Prior QA experience or understanding of QA methodologies is welcome. Offer: Cooperation based on a B2B contract and rate: 140-170 PLN/hour 100% remote work The support of a dedicated mentor. In the relationship, we focus on direct communication. When you join speedapp, you will be put in touch with a dedicated mentor who will make sure that you enjoy working with us and with the client. Events and integration meetings, as well as participation in various initiatives, e.g., sports. Access to the benefits offering (medical care, Multisport card). About Speedapp At speedapp, we believe that an organization is only as good as the people who make it up. We are a team of IT experts and other professionals working for our clients around the world (including Israel, Austria, USA). We go far beyond the HR category. We build IT teams and also help manage them. 👉 10 years of experience 👉 +100 clients worldwide +300 hires per year 💎 We have won the prestigious "Forbes Diamonds" award four times (2022, 2023, 2024, 2025). We are a member of the European Fast Growth Icons network and FinTech Poland. We are ranked 18th among the 100 fastest growing companies 2023 by Clutch.

🏢 Summary: Senior .NET Developer role focused on building and enhancing a cloud-native embedded finance platform in a regulated FinTech environment. The position involves designing, developing, and deploying scalable, secure features using a modern tech stack while ensuring high performance and reliability in production. You will work across backend and frontend technologies, contributing to CI/CD, cloud infrastructure, and event-driven systems. 🗂️ Requirements: 5+ years of software development experience, Strong OOP and system design skills, Hands-on experience with .NET and C#, Hands-on experience with Angular, Understanding of software testing concepts, Experience with cloud-native architectures, Experience with CI/CD and DevOps practices, Experience with relational databases, Experience with NoSQL databases, Knowledge of performance, security, and availability principles, Experience in FinTech, payments, banking, or regulated environments, Upper-Intermediate English or higher 📃 Skills: C#, .NET, Angular, AWS, CI/CD, Docker, Kubernetes, Kafka, RabbitMQ, Datadog, SQL, NoSQL, OOP, DDD 🏢 Description: Looking to take your .NET expertise to the next level while working on high-impact FinTech solutions? This role offers the chance to contribute to scalable, cloud-native systems that empower thousands of businesses worldwide. We’re seeking a Senior .NET Developer to join our team, collaborating with talented engineers, product managers, and designers to deliver innovative financial technology. At Sigma Software, we work with some of the most forward-thinking companies in the industry. This opportunity will let you grow professionally while making a tangible difference in a fast-paced, regulated environment. Customer Our customer is a leading FinTech company providing embedded financing solutions for platforms and marketplaces. Their mission is to enable businesses to offer flexible credit products to customers, helping SMEs access funding quickly and efficiently. The customer is recognized for innovation in embedded finance, serving thousands of businesses globally and partnering with major platforms. They operate in a regulated environment with a strong focus on scalability, performance, and security. Project The project involves enhancing and expanding customer’s embedded finance platform, which integrates directly into partner services to deliver fast, flexible funding to SMEs. You’ll work on a modern tech stack, building features that improve customer and partner experiences while ensuring reliability in production. Key Technologies: C#, .NET Core, Angular 18, AWS, CI/CD, Docker/Kubernetes, Kafka/RabbitMQ, Datadog, relational & NoSQL databases. Responsibilities Design, build, and deliver features and projects across C#, .NET Core, and Angular stack Write clean, maintainable, and well-tested code (unit/integration/e2e) Take ownership of features from requirements breakdown to deployment Deploy and monitor services in AWS cloud-native environments Handle production issues and incidents with accountability Collaborate with Product, Design, and Engineering teams in Agile practices Contribute to continuous improvement of systems and processes Requirements 5+ years of experience in software development with strong OOP and system design skills Solid hands-on experience with .NET (C#) and Angular Understanding of software testing concepts and practices Expertise in cloud-native and DevOps practices (CI/CD, automation, monitoring) Experience with relational and NoSQL databases Knowledge of non-functional requirements (performance, security, availability) Proven experience in FinTech, payments, banking, or regulated financial environments Upper-Intermediate English level or higher Will be a plus Experience with Docker/Kubernetes Familiarity with event-driven architectures (Kafka, RabbitMQ) Proficiency with observability tools (Datadog or similar) Knowledge of domain-driven design (DDD) and complex domain modeling Personal profile Growth mindset, curiosity, and proactivity Strong problem-solving skills balancing complexity and simplicity Feedback-oriented, open to giving and receiving constructive input Ownership & accountability in delivering commitments Team player with strong collaboration skills Adaptability to changing priorities Excellent communication skills across disciplines

🏢 Summary: Senior .NET Developer role focused on building and enhancing a scalable, cloud-native embedded finance platform in a regulated FinTech environment. The position involves designing and delivering full-stack features using .NET and Angular while ensuring high performance, security, and reliability in AWS. You will work on production-grade systems powering financial solutions for global businesses. 🗂️ Requirements: 5+ years of software development experience, Strong OOP and system design knowledge, Hands-on experience with C# and .NET, Hands-on experience with Angular, Understanding of software testing concepts and practices, Experience with cloud-native and DevOps practices, Experience with CI/CD, automation, and monitoring, Experience with relational databases, Experience with NoSQL databases, Knowledge of performance, security, and availability principles, Experience in FinTech, payments, banking, or regulated financial environments 📃 Skills: C#, .NET, Angular, AWS, CI/CD, SQL, NoSQL, OOP, DevOps, Testing 🏢 Description: Looking to take your .NET expertise to the next level while working on high-impact FinTech solutions? This role offers the chance to contribute to scalable, cloud-native systems that empower thousands of businesses worldwide. We’re seeking a Senior .NET Developer to join our team, collaborating with talented engineers, product managers, and designers to deliver innovative financial technology. At Sigma Software, we work with some of the most forward-thinking companies in the industry. This opportunity will let you grow professionally while making a tangible difference in a fast-paced, regulated environment. Customer Our customer is a leading FinTech company providing embedded financing solutions for platforms and marketplaces. Their mission is to enable businesses to offer flexible credit products to customers, helping SMEs access funding quickly and efficiently. The customer is recognized for innovation in embedded finance, serving thousands of businesses globally and partnering with major platforms. They operate in a regulated environment with a strong focus on scalability, performance, and security. Project The project involves enhancing and expanding customer’s embedded finance platform, which integrates directly into partner services to deliver fast, flexible funding to SMEs. You’ll work on a modern tech stack, building features that improve customer and partner experiences while ensuring reliability in production. Key Technologies: C#, .NET Core, Angular 18, AWS, CI/CD, Docker/Kubernetes, Kafka/RabbitMQ, Datadog, relational & NoSQL databases. Responsibilities Design, build, and deliver features and projects across C#, .NET Core, and Angular stack Write clean, maintainable, and well-tested code (unit/integration/e2e) Take ownership of features from requirements breakdown to deployment Deploy and monitor services in AWS cloud-native environments Handle production issues and incidents with accountability Collaborate with Product, Design, and Engineering teams in Agile practices Contribute to continuous improvement of systems and processes Requirements 5+ years of experience in software development with strong OOP and system design skills Solid hands-on experience with .NET (C#) and Angular Understanding of software testing concepts and practices Expertise in cloud-native and DevOps practices (CI/CD, automation, monitoring) Experience with relational and NoSQL databases Knowledge of non-functional requirements (performance, security, availability) Proven experience in FinTech, payments, banking, or regulated financial environments Upper-Intermediate English level or higher Will be a plus Experience with Docker/Kubernetes Familiarity with event-driven architectures (Kafka, RabbitMQ) Proficiency with observability tools (Datadog or similar) Knowledge of domain-driven design (DDD) and complex domain modeling Personal profile Growth mindset, curiosity, and proactivity Strong problem-solving skills balancing complexity and simplicity Feedback-oriented, open to giving and receiving constructive input Ownership & accountability in delivering commitments Team player with strong collaboration skills Adaptability to changing priorities Excellent communication skills across disciplines

🏢 Summary: Senior Backend/Fullstack Developer role focused on maintaining and improving a large-scale enterprise application for municipal waste collection and environmental services. The position involves solving complex backend issues, optimizing performance, developing REST APIs, and modernizing legacy systems using C# and .NET technologies. The developer will work independently within an Agile environment and contribute to architecture, testing, and continuous improvement initiatives. 🗂️ Requirements: 8+ years of professional software development experience, Strong experience with C# and .NET, Experience with enterprise backend development, Experience debugging complex production systems, Experience with legacy and monolithic applications, Strong SQL skills, Experience with PostgreSQL or relational databases, Experience with Entity Framework or similar ORM, Experience designing and consuming REST APIs, Experience with Git, GitHub and CI/CD pipelines, Experience writing Unit Tests and Integration Tests, Understanding of Agile Scrum methodologies, Ability to work independently, English communication skills 📃 Skills: C#, .NET, ASP.NET, PostgreSQL, SQL, EntityFramework, REST, Git, GitHub, CI/CD, Scrum, UnitTesting, IntegrationTesting 🏢 Description: Summary: The role of Senior Backend/Fullstack Developer is crucial for the evolution, an enterprise application that aids municipalities in managing waste collection and environmental services. This role focuses on solving complex technical problems and improving existing software rather than just creating new applications. Responsibilities: Develop and maintain a large-scale enterprise application built with C# and .NET. Troubleshoot and resolve complex production issues across the platform. Analyse existing solutions and improve maintainability through refactoring. Improve application performance and optimise database queries. Develop backend services and REST APIs. Work with PostgreSQL using both raw SQL and Entity Framework. Contribute to architecture discussions and technical decision-making. Write clean, maintainable and well-tested code. Implement Unit Tests and Integration Tests. Participate actively in Scrum ceremonies, refinement sessions and technical discussions. Contribute to continuous improvement initiatives across the development lifecycle. Help identify opportunities to leverage AI-assisted software development tools to improve engineering efficiency. Key Requirements: 8+ years of professional software development experience. Strong experience with C# and .NET (both .NET Framework and modern .NET). Solid understanding of enterprise backend development. Extensive experience debugging complex production systems. Experience working with legacy and monolithic applications. Strong SQL skills, including writing, analysing and optimising raw SQL queries. Experience with PostgreSQL or other relational databases. Experience using Entity Framework or similar ORM technologies. Experience designing and consuming REST APIs. Experience with Git, GitHub and CI/CD pipelines. Experience writing Unit Tests and Integration Tests. Good understanding of Agile methodologies (Scrum). Ability to work independently and proactively. Excellent English communication skills. Nice to Have: Experience with waste management systems. Experience in public sector software. Knowledge of utilities or environmental platforms. Understanding of SOLID principles. Experience in software architecture. Skills in performance optimisation. Familiarity with security best practices. Knowledge of domain-driven design. Experience with GitHub Copilot and AI-assisted software development. Understanding of process optimisation. Experience in technical mentoring. Other Details: Technical Environment: Includes C#, .NET, ASP.NET, PostgreSQL, REST APIs, Git/GitHub, CI/CD. Initial Onboarding: In the first three months, the developer will learn the RenoWeb platform, work independently on bug fixes, and deliver small tasks, with expectations of becoming largely autonomous by the end of the onboarding period.

🏢 Summary: Backend Developer (.NET) role focused on development, maintenance, and modernization of an existing logistics system. The position involves working with legacy code, fixing bugs, refactoring, and improving business logic within a live operational environment. The role requires close collaboration with development and analytics teams. 🗂️ Requirements: 3–5 years of experience with .NET, Proficiency in C#, Experience with ASP.NET MVC or ASP.NET Core, Strong knowledge of SQL Server, Experience working with legacy codebases, Ability to debug and analyze complex issues, Experience with REST API, English level B2 minimum 📃 Skills: .NET, C#, ASP.NET, MVC, Core, SQL, SQLServer, REST, EntityFramework, Docker, UnitTesting 🏢 Description: Organizacja z branży logistycznej, rozwijająca własne systemy operacyjne, poszukuje osoby na stanowisko Backend Developer (.NET). Rola skupiona jest na rozwoju i stabilizacji istniejącego systemu oraz stopniowym jego unowocześnianiu. Zakres obowiązków Rozwój i utrzymanie systemu w technologii .NET Analiza i rozwiązywanie błędów w systemie (bugfixy) Refaktoryzacja istniejącego kodu Analiza logiki biznesowej i jej usprawnianie Współpraca z zespołem developerskim i analitycznym Praca z kodem bez pełnej dokumentacji Wymagania Min. 3–5 lat doświadczenia w .NET Dobra znajomość: C# ASP.NET (MVC / Core) SQL Server Doświadczenie w pracy z istniejącym kodem (legacy) Umiejętność debugowania i analizy problemów Znajomość REST API Znajomość języka angielskiego na poziomie minimum B2 Mile widziane Entity Framework (klasyczny i Core) Podstawy testów jednostkowych Znajomość Docker Oferujemy Pracę przy systemach o realnym wpływie na operacje biznesowe Możliwość rozwoju technologicznego Stabilne zatrudnienie Wpływ na jakość i rozwój systemu

🏢 Summary: Backend Developer (.NET) role in a long-term enterprise project focused on development and maintenance of large-scale business systems. The position involves designing and implementing new features, optimizing existing solutions, and ensuring high performance and stability. Hybrid work model with strong emphasis on code quality and system reliability. 🗂️ Requirements: Experience with C#, Knowledge of .NET Core / .NET 6+, Experience with ASP.NET / ASP.NET Core (MVC, Web API), Experience with Entity Framework / EF Core (migrations, query optimization), Experience with MS SQL Server (T-SQL, stored procedures, indexes, optimization), Experience with migration scripts and Entity Framework, Experience with SQL Server Agent Jobs, Knowledge of HTML5 and CSS3, Experience with JavaScript and jQuery, Knowledge of Bootstrap, Experience with IIS configuration and manual deployments, Ability to monitor logs and diagnose errors, Knowledge of Windows Server, Experience with REST and SOAP, Knowledge of JSON and XML, Experience with GIT 📃 Skills: C#, .NET, ASP.NET, MVC, WebAPI, EF, SQL, TSQL, MSSQL, HTML5, CSS3, JavaScript, jQuery, Bootstrap, IIS, WindowsServer, REST, SOAP, JSON, XML, GIT 🏢 Description: Dla naszego klienta poszukujemy Backend Developera (.NET) do długoterminowego projektu związanego z rozwojem i utrzymaniem systemów biznesowych o dużej skali. Rola obejmuje projektowanie i rozwój nowych funkcjonalności, optymalizację istniejących rozwiązań oraz współpracę z zespołami frontendowymi i infrastrukturalnymi. Projekt realizowany jest w środowisku enterprise, z naciskiem na jakość kodu, wydajność oraz stabilność systemów. Tryb pracy Praca hybrydowa: 3 dni pracy zdalnej 2 dni pracy w biurze w Warszawie Start Od zaraz (możliwość dopasowania terminu rozpoczęcia dla odpowiedniego kandydata) Wymagane kompetencje Backend / .NET Wymagane: C#, .NET Core / .NET 6+ ASP.NET / ASP.NET Core (MVC, Web API) Entity Framework / EF Core (migracje, optymalizacja zapytań) Mile widziane: .NET Framework 4.8 REST / SOAP Programowanie asynchroniczne i wielowątkowe Znajomość zasad SOLID i wzorców projektowych WCF, WinForms, WPF Office Interop / COM Interop Bazy danych Wymagane: MS SQL Server (T-SQL, procedury składowane, indeksy, optymalizacja) Skrypty migracyjne, praca z Entity Framework SQL Server Agent Jobs (harmonogramowanie i automatyzacja zadań) Mile widziane: SSIS (ETL) SAS, PostgreSQL, Oracle, Teradata Frontend Wymagane: HTML5, CSS3 JavaScript, jQuery Bootstrap DevOps / Utrzymanie Wymagane: IIS (konfiguracja, wdrożenia manualne) Monitorowanie logów i diagnostyka błędów Windows Server Mile widziane: WPF / WinForms (aplikacje desktopowe) Podstawy UNIX Dodatkowe kompetencje Komunikacja międzyserwisowa (REST, SOAP, JSON, XML) GIT

🏢 Summary: Development role focused on designing and building complex desktop ERP applications in C#/.NET using a 3-tier architecture and MVVM pattern. The position involves full lifecycle development, architectural decision-making, code quality assurance, and collaboration in a Scrum team. The candidate will work on expanding and maintaining advanced business systems. 🗂️ Requirements: Commercial experience in C# and .NET, Experience with MVVM pattern and 3-tier architecture, Experience in desktop application development (WinForms or WPF), Knowledge of Oracle or PostgreSQL databases, Strong SQL skills, Experience with Git (branching, merge, Gitflow), Knowledge of APIs and web technologies, Understanding of OOP and design patterns, Experience with multithreading and asynchronous programming, Experience with CI/CD pipelines, Experience with unit testing 📃 Skills: C#, .NET, MVVM, WinForms, WPF, Oracle, PostgreSQL, SQL, Git, Gitflow, API, OOP, CI/CD, TDD, Scrum 🏢 Description: 💻 Mid / Senior C# / .NET Developer (Desktop / ERP) Szukamy doświadczonego developera C# / .NET, który ma realne doświadczenie w budowie aplikacji desktopowych w architekturze 3-warstwowej i wzorcu MVVM. Jeśli pracowałeś przy złożonych systemach (np. ERP) i lubisz mieć wpływ na architekturę — to rola dla Ciebie. 🚀 Twoja rola Projektowanie i rozwój aplikacji (od koncepcji po wdrożenie) Tworzenie nowych funkcjonalności i rozwój istniejących systemów Debugowanie i rozwiązywanie problemów Code review i dbanie o jakość kodu Tworzenie testów jednostkowych Współpraca w zespole Scrumowym Udział w decyzjach architektonicznych Dokumentacja techniczna i dzielenie się wiedzą 🧠 Kluczowe wymagania (must-have) C# / .NET – bardzo dobra znajomość + doświadczenie komercyjne Doświadczenie w MVVM + aplikacjach 3-warstwowych (WARUNEK KONIECZNY) Doświadczenie w aplikacjach desktopowych (WinForms / WPF) Znajomość baz danych (Oracle / PostgreSQL) + SQL Praca z GIT (branching, merge, Gitflow) Znajomość API i technologii webowych Zrozumienie: OOP, clean code, dobrych praktyk wielowątkowości, async, zarządzania pamięcią architektury aplikacji i wzorców projektowych Doświadczenie z CI/CD i testami (TDD mile widziane) ⭐ Mile widziane DevExpress (WinForms) Docker / konteneryzacja Doświadczenie w systemach ERP (kadry/płace/finanse) SCRUM + narzędzia (Jira, Confluence, Bitbucket) CQRS, DDD GitHub / portfolio 🎁 Co oferujemy Krótki, 14-dniowy termin płatności faktury Bogaty pakiet prywatnej opieki medycznej Dostęp do platformy kafeteryjnej MyBenefit ( m.in . Multisport, karty przedpłacone: Ikea, Zalando, Notino i inne)

🏢 Summary: Senior Backend Developer (remote, 12-month contract) focused on building scalable data processing systems and robust data pipelines. The role involves designing system architecture, coding for scale, and collaborating across teams while experimenting with new technologies and MVPs. 🗂️ Requirements: BSc in Software Engineering, Computer Science or related field, 5+ years of experience with Python, Hands-on experience with data pipelines, Experience designing scalable system architectures, Experience in backend software development 📃 Skills: Python, AWS, CI/CD, DevOps, SQL, ElasticSearch, OpenSearch, Neptune, Neo4j 🏢 Description: Start: ASAP Work model: Remote Length of contract: 12 months + extensions We’re looking for a Senior Backend Developer with a data pipeline emphasis with a strong understanding of and hands-on experience with broad software development, i.e., system architecture, coding for scale, and communicating possibilities for what can be built and maintained, as well as a love for experimenting and building MVPs. Core Responsibilities: Design and implement software architectures for scalable data processing systems. Develop and maintain data pipelines for efficient data ingestion and processing. Collaborate with cross-functional teams to define and streamline software development processes. Participate in code reviews and maintain high software quality standards. Experiment with new technologies and frameworks to enhance system performance. Key Requirements: BSc in Software Engineering, Computer Science, or other relevant field 5+ years of experience with Python Experience with data pipelines Nice to Have: Experience with one or more AWS services AWS DevOps CI/CD Pipelines Relational databases ElasticSearch/OpenSearch Graph databases (e.g., Neptune or Neo4j)