Senior .Net Backend Engineer

🏢 Summary: Senior .NET Backend Engineer role focused on building modern API and event-driven integrations for research systems in the pharmaceutical industry. The position involves replacing legacy APIs, implementing cloud-based integration solutions, and supporting event-driven architecture initiatives in a remote or hybrid B2B setup. Long-term contract with English-speaking environment and collaboration with technical and business stakeholders. 🗂️ Requirements: Strong experience with .NET, Experience with ASP.NET Core, Experience building enterprise integration APIs, Knowledge of Azure or AWS, Experience with Infrastructure as Code, Hands-on experience with Entity Framework, Experience with unit testing, Knowledge of software quality practices, Strong analytical and problem-solving skills, Ability to work independently, Excellent communication skills, Confidence working with stakeholders 📃 Skills: .NET, ASP.NET, Azure, AWS, Bicep, EntityFramework, Kafka, Redis, Docker, CI/CD, GitHub, APIs 🏢 Description: Work mode - fully remote or hybrid - 2 days from the office in Warsaw. Assignment type: B2B Contract length: 10-12 months with possible extensions. Start: ASAP or within 1 month. Language: English. Industry: pharmaceutical. Recruitment process: 2 interviews with the client. Workload: Full time. Summary: The Senior .Net Backend Engineer role is focused on building innovative integrations for research systems. The primary objective is to modernize data exchange mechanisms to enhance scientific work and accelerate innovation in research. Main Responsibilities: - Build API and event-based integrations between existing and new research systems. - Replace current legacy APIs with a new modern greenfield API surface. - Assist feature teams with identifying and implementing event-driven architecture. Key Requirements: - Strong experience developing backend applications using .NET / ASP.NET Core. - Experience building enterprise integration APIs. - Knowledge of cloud platforms such as Azure and/or AWS. - Experience with Infrastructure as Code (e.g., Bicep). - Hands-on experience with Entity Framework. - Experience with unit testing and modern software quality practices. - Strong analytical and problem-solving skills. - Ability to work independently with a high degree of ownership and accountability. - Excellent communication skills and confidence working directly with stakeholders. Nice to Have: - Experience with Kafka. - Knowledge of Electronic Laboratory Notebooks (ELN). - Familiarity with Redis. - Experience with Docker / Container Apps. - Knowledge of CI/CD practices, GitHub Actions. Other Details: Team Context: Works closely with technical and business stakeholders in a collaborative environment.

🏢 Summary: Senior Software Developer role focused on designing and implementing complex API and microservice integrations in a banking environment using Azure and .NET. The position combines solution design with hands-on development, owning the full lifecycle of secure, low-latency integration solutions. The developer will lead Azure-based integrations, optimize Python transformations, and ensure high-quality, well-monitored applications. 🗂️ Requirements: 7+ years of hands-on experience with Azure development, Strong experience with .NET development, Experience building integration solutions using .NET and Azure, Experience with Azure Functions, APIM, Service Bus, App Insights, Working knowledge of Python for integration and transformation tasks, Experience writing and maintaining unit tests, Expertise in Application Insights monitoring and optimization, Experience designing integration patterns in CRM context 📃 Skills: Azure, AzureFunctions, ServiceBus, APIM, AppInsights, .NET, Python, Microservices, APIs, CRM, UnitTesting 🏢 Description: 🌍 Work mode: hybrid (preferably from Krakow or Warsaw): • People from Krakow and Warsaw - 6x per month in the office • People outside of Krakow and Warsaw - 1-2x per month in the office ⏰ Start : June/July 2026. 📝 Contract : B2B. ⏳ Duration : >12 months contracts. 📕 Project language : English. 💼 Industry : Banking. 📑 Workload: Full time. ⚙️ Recruitment process : 1h technical screening on zoom. 💻 Equipment : Work on emagine or your own equipment. We are looking for a Senior Software Developer who thrives at the intersection of technical design and hands-on execution . In this role, you will be the technical engine driving key initiatives for integration projects. Unlike a traditional architect role, your focus will be on Solution Design: creating the technical 'how-to' for complex integrations and then leading the end-to-end development . Main Responsibilities: Draft end-to-end technical designs for API solutions and microservice integration patterns. Own the full development cycle, ensuring secure, low-latency communication paths between backend systems and UI/UX layers. Manage the technical integration of platforms using Azure Functions and Service Bus. Fine-tune Python-based code mainly for specific transformations (e.g. Pendo-related) while having the agility to refactor logic as needed. Participate in design reviews and incorporate stakeholder feedback. Support discussions surrounding potential migrations to managed environments. Key Requirements: 7+ years of hands-on experience in Azure development (Functions, App Insights, APIM, and Service Bus ). Strong experience in .NET development (primary technology.) Experience in building integration solutions using . NET and Azure. Expertise in Python (basic/working knowledge required, mainly for integration/transformation tasks), with strong proficiency in .NET. A 'quality-first' mindset with extensive experience writing and maintaining unit tests. Deep expertise in using Application Insights for monitoring and optimizing live applications. Proven experience in designing and building integration patterns within a CRM context. Nice to Have: Exposure to Power Platform (optional) . Experience with Google Cloud Platform (GCP). Prior experience with Highspot, Pendo, or MS Dynamics integrations.

🏢 Summary: Senior Full-Stack Developer role focused on designing and delivering complex API and microservice integration solutions in a banking environment. The position combines end-to-end solution design with hands-on development, particularly within Azure-based ecosystems. The developer will lead secure, low-latency integrations and support future platform migrations. 🗂️ Requirements: 7+ years of hands-on Azure development experience, Experience with Azure Functions, APIM, Service Bus and Application Insights, Strong proficiency in Python, Strong proficiency in Java or .NET, Experience designing API solutions and microservice integration patterns, Experience building integrations within CRM environments, Experience writing and maintaining unit tests, Experience monitoring and optimizing applications using Application Insights, Ability to design secure, low-latency system integrations 📃 Skills: Azure, Functions, APIM, ServiceBus, AppInsights, Python, Java, .NET, APIs, Microservices, CRM, UnitTesting 🏢 Description: 🌍 Work mode: hybrid (preferably from Krakow or Warsaw): • People from Krakow and Warsaw - 6x per month in the office • People outside of Krakow and Warsaw - 1-2x per month in the office ⏰ Start : June/July 2026. 📝 Contract : B2B. ⏳ Duration : >12 months contracts. 📕 Project language : English. 💼 Industry : Banking. 📑 Workload: Full time. ⚙️ Recruitment process : 1h technical screening on zoom. 💻 Equipment : Work on emagine or your own equipment. We are looking for a Senior Full-Stack Developer who thrives at the intersection of technical design and hands-on execution . In this role, you will be the technical engine driving key initiatives for integration projects. Unlike a traditional architect role, your focus will be on Solution Design: creating the technical 'how-to' for complex integrations and then leading the end-to-end development . Main Responsibilities: Draft end-to-end technical designs for API solutions and microservice integration patterns. Own the full development cycle, ensuring secure, low-latency communication paths between backend systems and UI/UX layers. Manage the technical integration of platforms using Azure Functions and Service Bus. Fine-tune Python-based code while having the agility to refactor logic as needed. Participate in design reviews and incorporate stakeholder feedback. Support discussions surrounding potential migrations to managed environments. Key Requirements: 7+ years of hands-on experience in Azure development (Functions, App Insights, APIM, and Service Bus ). Expertise in Python, with strong proficiency in Java or .NET. A 'quality-first' mindset with extensive experience writing and maintaining unit tests. Deep expertise in using Application Insights for monitoring and optimizing live applications. Proven experience in designing and building integration patterns within a CRM context. Nice to Have: Experience with Google Cloud Platform (GCP). Prior experience with Highspot, Pendo, or MS Dynamics integrations. Other Details: This position will involve working on integration projects, with potential opportunities for remote collaboration. The role emphasizes hands-on development and strategic planning for future migrations.

🏢 Summary: Senior Full-Stack Developer role focused on designing and delivering end-to-end integration solutions within a banking environment, with strong emphasis on Azure-based architectures and hands-on development. The position combines solution design responsibilities with full development lifecycle ownership, particularly around APIs and microservices. Long-term B2B contract with hybrid work model and English-speaking project context. 🗂️ Requirements: 7+ years of experience in Azure development, Hands-on experience with Azure Functions, App Insights, APIM and Service Bus, Strong expertise in Python, Strong proficiency in Java or .NET, Experience in writing and maintaining unit tests, Expertise in Application Insights for monitoring live applications, Experience in designing and building integration patterns in CRM context, Ability to design end-to-end API and microservice integrations 📃 Skills: Azure, Functions, AppInsights, APIM, ServiceBus, Python, Java, .NET, APIs, Microservices, CRM, UnitTesting, GCP 🏢 Description: 🌍 Work mode: hybrid (preferably from Krakow or Warsaw): • People from Krakow and Warsaw - 6x per month in the office • People outside of Krakow and Warsaw - 1-2x per month in the office ⏰ Start : June/July 2026. 📝 Contract : B2B. ⏳ Duration : >12 months contracts. 📕 Project language : English. 💼 Industry : Banking. 📑 Workload: Full time. ⚙️ Recruitment process : 1h technical screening on zoom. 💻 Equipment : Work on emagine or your own equipment. We are looking for a Senior Full-Stack Developer who thrives at the intersection of technical design and hands-on execution . In this role, you will be the technical engine driving key initiatives for integration projects. Unlike a traditional architect role, your focus will be on Solution Design: creating the technical 'how-to' for complex integrations and then leading the end-to-end development . Main Responsibilities: Draft end-to-end technical designs for API solutions and microservice integration patterns. Own the full development cycle, ensuring secure, low-latency communication paths between backend systems and UI/UX layers. Manage the technical integration of platforms using Azure Functions and Service Bus. Fine-tune Python-based code while having the agility to refactor logic as needed. Participate in design reviews and incorporate stakeholder feedback. Support discussions surrounding potential migrations to managed environments. Key Requirements: 7+ years of hands-on experience in Azure development (Functions, App Insights, APIM, and Service Bus ). Expertise in Python, with strong proficiency in Java or .NET. A 'quality-first' mindset with extensive experience writing and maintaining unit tests. Deep expertise in using Application Insights for monitoring and optimizing live applications. Proven experience in designing and building integration patterns within a CRM context. Nice to Have: Experience with Google Cloud Platform (GCP). Prior experience with Highspot, Pendo, or MS Dynamics integrations. Other Details: This position will involve working on integration projects, with potential opportunities for remote collaboration. The role emphasizes hands-on development and strategic planning for future migrations.

🏢 Summary: Senior .NET Developer role focused on building backend microservices and cloud integrations for scalable digital platforms using .NET Core and Azure-related technologies. The position involves developing backend functionalities, partner integrations, search engines, and database optimization in a hybrid or remote work model. 🗂️ Requirements: 5+ years of experience as a Backend .NET Developer, Strong knowledge of .NET Core, Strong knowledge of C#, Experience with SQL Server, Experience creating and optimizing SQL queries, Experience with messaging systems, Business-level Polish communication, Communicative English proficiency, Legal right to work in the European Union 📃 Skills: .NET, C#, SQL, SQLServer, CosmosDB, Azure, AzureServiceBus, EventHub, Kafka, MQ, Elasticsearch, MongoDB, Swagger, OpenAPI, Microservices 🏢 Description: Empower the future of backend development by architecting innovative microservices and seamless cloud integrations. Warszawa-based opportunity with a hybrid work model (1 day in-office per week, typically on Mondays). Fully remote work is also possible but prioritized second. As a Senior .NET Developer – Microservices and Cloud Integration, you will be working on the development of complex backend systems, focusing on microservices architecture and cloud-based integrations, supporting scalable and robust digital platforms. This role offers a path to impactful projects and career growth in a dynamic environment. Your main responsibilities: - Design and implement new backend functionalities on the Goodie platform using .NET Core. - Develop and maintain microservices and external partner integrations. - Implement and enhance content search engines. - Work with SQL Server and Cosmos DB for data querying and optimization. - Participate in requirement analysis, backlog refinement, and sprint planning. - Ensure code quality through unit tests, code reviews, and adherence to best practices. You're ideal for this role if you have: - Minimum 5 years of experience as a Backend .NET Developer. - Strong knowledge of .NET Core / C#. - Experience with SQL Server, including query creation and optimization. - Familiarity with messaging systems, preferably Azure Service Bus or Event Hub, or alternatives like Kafka or MQ. - Proficient communication skills in Polish and English at a business level. It is a strong plus if you have: - Experience with Azure AI Search or Elasticsearch. - Knowledge of Azure Cosmos DB, MongoDB, or other NoSQL databases. - Experience with Azure cloud services (App Services, Functions, Storage, Application Insights, Log Analytics). - API documentation skills using Swagger / OpenAPI. - Backend development experience for mobile applications. Language Required for the role: - Polish (business communication level) - English (communicative proficiency) Eligibility for the role: - Only candidates with an existing legal right to work in the European Union will be considered for this role.

🏢 Summary: B2B contract for an experienced Backend Software Engineer to design, build, and operate cloud-native backend services on Microsoft Azure in a 100% remote model. The role focuses on end-to-end ownership of scalable, event-driven services, including development, deployment, and DevOps activities using modern Azure and container technologies. 🗂️ Requirements: Strong experience with C# and .NET in backend development, Practical experience with Microsoft Azure services, Experience with AKS and containerized workloads, Experience with messaging systems such as Service Bus or Kafka, Knowledge of SQL databases and data modeling, Experience with CI/CD pipelines, Experience with Infrastructure as Code using Terraform, Understanding of event-driven architecture 📃 Skills: C#, .NET, Azure, AKS, ServiceBus, Kafka, APIManager, SQL, Terraform, CI/CD, Kubernetes, DevOps 🏢 Description: Start Date: ASAP / Within 1 Month / Flexible Work Model: 100% remote Contract Type: B2B (140-150 PLN/h + VAT) We are looking for an experienced Backend Software Engineer to join a cloud‑native development team delivering scalable services on Microsoft Azure. The role focuses on designing, building, and operating backend services end‑to‑end in a modern, event‑driven architecture. You will take full ownership of your services, from development through deployment and ongoing support, working closely with architects and platform stakeholders. Responsibilities: Design, build, test, and deploy backend services and APIs using C# and .NET. Take ownership of build, release, and DevOps activities for assigned services. Develop and support event‑driven and messaging‑based architectures on Microsoft Azure. Deploy and manage containerised workloads using Azure Kubernetes Service (AKS). Provision and maintain infrastructure using Terraform in line with platform and client standards. Expectations: Strong hands‑on experience with C# / .NET i n backend service development. Practical experience with Microsoft Azure, including AKS, Service Bus or Kafka, and API Manager. Solid knowledge of SQL databases and data modelling concepts. Familiarity with CI/CD pipelines, DevOps best practices, and infrastructure as code. Ability to work effectively in agile teams, with strong problem‑solving and communication skills. What We Offer: Medicover healthcare package Multisport card Access to an e-learning platform Group life insurance

🏢 Summary: B2B contract for a Mid/Senior FullStack Engineer to modernize and migrate legacy .NET applications to a modular, cloud-native Azure architecture in the banking sector. The role combines backend development in .NET with frontend work in React, focusing on refactoring legacy systems, building scalable APIs, and implementing CI/CD and observability practices. Hybrid work model with strong influence on architectural decisions and cloud migration. 🗂️ Requirements: 5+ years of commercial experience with C# and .NET (Framework and .NET Core/6+), Strong proficiency in EF Core and MSSQL (query tuning, transactions, indexing), Commercial experience with React and TypeScript, Experience building and securing REST APIs (authentication, versioning, validation), Familiarity with Azure services (App Service, Functions, SQL, Service Bus, Storage), Experience with automated testing (unit, integration, contract, E2E), Experience with CI/CD pipelines (Azure DevOps or GitHub Actions), Ability to work with legacy .NET codebases (ASP.NET MVC, Razor, WPF, WinForms), English at B2+ level 📃 Skills: C#, .NET, .NETCore, .NET6, .NET8, EFCore, MSSQL, T-SQL, React, TypeScript, REST, Azure, AppService, AzureFunctions, AzureSQL, ServiceBus, AzureStorage, xUnit, Jest, Playwright, Cypress, Git, AzureDevOps, GitHubActions, ASP.NET, MVC, Razor, WPF, WinForms, DDD, CleanArchitecture 🏢 Description: We are looking for FullStack Engineer (.NET & React) Location: Kraków / Hybrid (7 days in the office per month) Contract Type: B2B Contract Seniority: Mid / Senior About the Project Join a high-impact modernization initiative for a leading player in the banking sector . We are transforming a portfolio of approximately a dozen .NET applications and MSSQL databases into a modular, cloud-native Azure architecture. As a FullStack Engineer, you will play a dual role: evolving existing production services (including legacy UI and desktop components) while systematically extracting business logic to re-implement it into a modern, scalable ecosystem. This is a unique opportunity to influence the transition from monolithic architectures to high-performance, distributed cloud services. Your Responsibilities Design & Development: Build backend services and APIs using .NET 6/8 following Clean Architecture and DDD patterns. Frontend Evolution: Develop and maintain React + TypeScript frontends, managing the incremental migration from legacy UI modules. Modernization: Read, refactor, and extract complex business logic from legacy .NET codebases and T-SQL stored procedures. Quality Assurance: Write and maintain comprehensive automated tests (Unit, Integration, Contract, and E2E). DevOps & Observability: Create CI/CD pipelines (Azure DevOps/GitHub Actions) and instrument services for deep observability (metrics, logs, distributed traces). Collaboration: Participate in domain modeling, architecture discussions, and Agile ceremonies with Architects and Product Owners. Skills & Experience We Require Experience: 5+ years of commercial experience with C# and the .NET ecosystem (both Framework and .NET Core/6+). Database Expertise: Strong proficiency in EF Core and MSSQL (including query tuning, transactions, and indexing). Frontend: Solid production experience with React and TypeScript. Web Services: Practical experience in building and securing REST APIs (Auth, Versioning, Validation). Cloud: Familiarity with Azure services (App Service, Functions, SQL, Service Bus, Storage). Testing & Tooling: Experience with xUnit, Jest, and Playwright/Cypress, as well as disciplined Git practices. Legacy Handling: The ability to read and reason about legacy codebases (ASP.NET MVC, Razor, WPF, or WinForms). Communication: English at a B2+ level for technical documentation and team collaboration. Nice to Have Experience with Infrastructure as Code (Terraform or Bicep). Knowledge of Docker and Kubernetes (AKS). Background in migrating monoliths to microservices. Azure Developer Associate certification. What We Offer Impact: Real influence on the architecture and the cloud migration roadmap. Autonomy: Direct collaboration with Tech Leads and Architects in a flat structure. Modern Stack: Opportunity to work with the latest .NET versions (6/8) and React. Efficiency: Fast technical onboarding with immediate access to repos, CI/CD pipelines, and monitoring tools. Flexible Hybrid Model: Remote-first approach with only 7 planned days in the Kraków office per month. Benefits : Luxmed and Multisport Card

🏢 Summary: Senior .Net API Developer responsible for designing and leading the development of secure, scalable REST APIs within a Nordic commercial integration layer in the Auto and Consumer Finance domain. The role focuses on backend API development, architectural collaboration, and improving performance and reliability in a large international project. Offered as a remote B2B contract. 🗂️ Requirements: Senior-level backend development experience, .NET / .NET Core experience, Experience designing and developing REST APIs, Knowledge of OAuth, Experience with Azure, Experience with Azure DevOps, Strong architectural and design skills, Ability to lead API/application development initiatives, Experience translating business requirements into technical solutions 📃 Skills: .NET, .NET Core, REST, OAuth, Azure, Azure DevOps, C#, SQL, NoSQL, PowerShell, AKS, SOLID, Application Insights, Azure API Management 🏢 Description: Summary: The Senior .Net API Developer role focuses on developing and maintaining the Nordic commercial integration layer, enhancing secure and scalable integrations within the Auto and Consumer Finance space. The primary goal is to lead initiatives in backend API development while maintaining high standards of quality and technical stability. What we offer: Remote Role B2B Contract Big International project Rate: 160-180 zł/day +VAT Responsibilities: Design and implement new external partner REST APIs Lead backend development initiatives from idea to production Translate complex business requirements into scalable technical solutions Contribute to architectural decisions in collaboration with the Architect Maintain and enhance existing integration services Improve performance, scalability, and reliability Produce and maintain technical documentation Ensure adherence to architectural guidelines and security standards Participate in agile ceremonies and technical discussions Key Requirements: Senior-level backend development experience Proven ability to lead development of new applications and APIs Strong architectural understanding and design capabilities Experience with .NET / .NET Core Hands-on knowledge of RESTful services and OAuth Technical expertise in Azure and Azure DevOps Nice to Have: Experience with Application Insights Knowledge of PowerShell Familiarity with Azure API Management Understanding of SQL/NoSQL databases Experience with AKS and SOLID principles

🏢 Summary: Senior .NET Developer role focused on designing, extending, and modernising critical banking and securities systems in a fully remote B2B model. The position involves full-stack development, system integration, and cloud scaling within distributed, business-critical environments. The role requires close collaboration with business stakeholders and ownership of end-to-end application delivery. 🗂️ Requirements: 5+ years experience as .NET / C# Developer, Experience in banking or investment banking sector, Full-stack development experience, Knowledge of SOLID design principles, Experience with document-based databases, Experience with event-driven messaging frameworks, Experience with unit and integration testing, End-to-end application development experience, Ability to work during UK business hours, Based in Poland 📃 Skills: .NET, C#, MongoDB, SOLID, Messaging, UnitTesting, IntegrationTesting, Docker, Kubernetes, Cloud 🏢 Description: Work model: 100% remote (candidates must be based in Poland) Contract type: B2B Industry: Banking / Investment Banking We are looking for an experienced Senior .NET Developer to join a distributed engineering team working on critical banking systems. The role focuses on extending and modernising applications used across securities and banking operations, with a strong emphasis on system design, scalability, and cloud transformation. You will work end-to-end on business-critical systems, closely collaborating with Business Analysts, without a separate QA team. A solid background in banking or financial services is essential. Main Responsibilities: Design, develop, and extend .NET-based systems supporting multiple banking entities Contribute to the integration of securities and core banking platforms Support and enhance a portfolio of ~17 applications across product control and risk management Work with an in-house development framework in a full-stack capacity Participate in scaling applications for cloud-based, containerized environments Collaborate closely with business stakeholders to deliver robust solutions Ensure high code quality through unit and integration testing Key Requirements: 5+ years of professional experience as a .NET / C# Developer Hands-on experience in the banking or investment banking sector (mandatory) Full-stack development experience (backend-focused, frontend included) Strong understanding and practical application of SOLID design principles Experience with document-based databases (e.g. MongoDB) Experience with event-driven / event-based messaging frameworks Solid knowledge of unit and integration testing Experience working end-to-end on applications (development, testing, support) Ability to work independently in a fast-paced, regulated environment Availability during UK business hours Nice to Have: Experience with cloud platforms and application migration to cloud Experience with container technologies (e.g. Docker, Kubernetes) Exposure to systems such as Murex or large in-house banking platforms Background in securities, risk, or product control systems Other Details: This role is 100% remote with candidates required to be located in Poland. The contract is on a B2B basis within the banking and investment banking industry.

🏢 Summary: Senior .NET Developer role focused on designing, extending, and modernizing critical banking systems within securities and core banking domains. The position involves full-stack development, system integration, and cloud scaling in a distributed team without a separate QA function. Work includes end-to-end ownership of business-critical applications in a regulated investment banking environment. 🗂️ Requirements: 5+ years experience with .NET and C#, Hands-on experience in banking or investment banking, Full-stack development experience, Strong knowledge of SOLID principles, Experience with document-based databases, Experience with event-driven messaging frameworks, Knowledge of unit and integration testing, End-to-end application development experience, Ability to work independently in regulated environments, Availability during UK business hours, Poland-based residency 📃 Skills: .NET, C#, MongoDB, SQL, REST, Microservices, Docker, Kubernetes, Azure, UnitTesting, IntegrationTesting, EventDriven, Git 🏢 Description: Work model: 100% remote (candidates must be based in Poland) Contract type: B2B Industry: Banking / Investment Banking We are looking for an experienced Senior .NET Developer to join a distributed engineering team working on critical banking systems. The role focuses on extending and modernising applications used across securities and banking operations, with a strong emphasis on system design, scalability, and cloud transformation. You will work end-to-end on business-critical systems, closely collaborating with Business Analysts, without a separate QA team. A solid background in banking or financial services is essential. Main Responsibilities: Design, develop, and extend .NET-based systems supporting multiple banking entities Contribute to the integration of securities and core banking platforms Support and enhance a portfolio of ~17 applications across product control and risk management Work with an in-house development framework in a full-stack capacity Participate in scaling applications for cloud-based, containerized environments Collaborate closely with business stakeholders to deliver robust solutions Ensure high code quality through unit and integration testing Key Requirements: 5+ years of professional experience as a .NET / C# Developer Hands-on experience in the banking or investment banking sector (mandatory) Full-stack development experience (backend-focused, frontend included) Strong understanding and practical application of SOLID design principles Experience with document-based databases (e.g. MongoDB) Experience with event-driven / event-based messaging frameworks Solid knowledge of unit and integration testing Experience working end-to-end on applications (development, testing, support) Ability to work independently in a fast-paced, regulated environment Availability during UK business hours Nice to Have: Experience with cloud platforms and application migration to cloud Experience with container technologies (e.g. Docker, Kubernetes) Exposure to systems such as Murex or large in-house banking platforms Background in securities, risk, or product control systems Other Details: This role is 100% remote with candidates required to be located in Poland. The contract is on a B2B basis within the banking and investment banking industry.