Senior Full Stack Developer - Portfolio Management System

Luxoft; Polska; Hybrid; PLN 260,000 - 420,000; Full time

Job summary

Luxoft seeks an experienced Software Developer to modernize a mission-critical Portfolio Management System used by investment professionals. The role focuses on transforming a mature WPF-based desktop platform into a scalable, high-performance ecosystem with API development and AI-enabled user experiences.

You will work across frontend, backend, service, integration, and data layers, addressing performance, architecture simplification, and technical debt while preserving essential front-office

Qualifications

• 10+ years of professional software engineering delivering enterprise applications.
• Strong C# and .NET experience across .NET Framework and .NET Core/5+.
• Deep WPF, XAML, MVVM, desktop architecture, and multithreading knowledge.
• Experience in buy-side investment tech (PMS/OMS/EMS/workflows).
• Hands-on DevExpress experience with complex grids and performance UI.
• Experience designing RESTful APIs with ASP.NET Core.
• Python development for services, automation, analytics, or AI components.
• Strong SQL Server development and performance tuning.
• Experience building web-based and rich desktop/fat-client applications.
• Proficiency in profiling, diagnostics, memory management, performance tuning, production troubleshooting.

Responsibilities

• Modernize the PMS using .NET, WPF, and DevExpress.
• Refactor legacy components, reduce technical debt, and improve maintainability.
• Enhance UX while preserving front-office workflows.
• Design and implement RESTful APIs for PMS data access.
• Develop integrations with trading, risk, reporting, analytics, and downstream systems.
• Implement authentication, authorization, validation, auditing, observability, and error handling.
• Optimize performance across desktop, server, DB, and integration layers.
• Introduce AI-enabled features and enterprise AI gateways.
• Collaborate with investment users to deliver high-value AI use cases.

Skills

10+ years of professional software eng

C# and .NET expertise

WPF/XAML/MVVM

Desktop architecture & multithreading

Buy-side investment tech experience

RESTful API design

Python for services/AI

SQL Server performance tuning

Git, CI/CD, Azure DevOps

Web and desktop/fat-client development

Tools

DevExpress UI components

ASP.NET Core

Azure DevOps

MongoDB

React/Angular (web frameworks)

Job description

Project description

We are seeking an experienced Software Developer to help modernize a mission-critical Portfolio Management System (PMS) used by investment professionals across front-office investment functions.The successful candidate will play a key role in transforming a mature WPF-based desktop platform into a modern, scalable, high-performance application ecosystem. The work includes UI modernization, platform upgrades, API development, performance optimization, architecture simplification, technical debt reduction, and AI-enabled user experiences.This role is well suited to an engineer with experience in buy-side portfolio, order, execution, risk, or investment analytics platforms who is comfortable working across desktop, web, service, integration, and data layers.

Responsibilities

• Key Responsibilities:Application Modernization
• Upgrade and modernize existing .NET, WPF, and DevExpress applications.
• Refactor legacy components, reduce technical debt, and improve maintainability.
• Improve the application user experience while preserving critical front-office workflows.
• Contribute to target architecture decisions and phased modernization plans.Performance Engineering
• Investigate and resolve application freezing, slow response times, memory leaks, and crashes.
• Profile and optimize desktop, server-side, database, and integration components.
• Improve data loading, caching, processing, and resource-management patterns.
• Implement appropriate diagnostics, logging, health monitoring, and performance measures.
• Reduce reliance on legacy SOA, middleware, and tightly coupled dependencies.
• Design simpler service-oriented and API-first components.
• Support migration toward modular, scalable, and supportable architecture patterns.
• Assess MongoDB dependencies and recommend pragmatic simplification or replacement approaches.
• Design and build secure RESTful APIs for PMS data access.
• Develop integrations with trading, risk, reporting, analytics, and downstream systems.
• Implement authentication, authorization, validation, auditing, observability, and error handling.
• Produce clear API specifications and technical documentation.
• Build an AI-powered prompt/chat experience within the PMS.
• Integrate enterprise Large Language Models and approved AI services.
• Develop prompt orchestration, tool-calling, retrieval, guardrails, and workflow automation capabilities.
• Partner with investment users to identify and deliver high-value, controlled AI use cases.
• Maintain and enhance rich desktop capabilities while introducing web-based applications where appropriate.
• Deliver across frontend, backend, service, integration, and data layers.
• Apply automated testing, code review, secure development, and CI/CD practices.

SKILLS

Must have

• 10+ years of professional software engineering experience delivering enterprise applications.
• Strong C# and .NET experience, including legacy .NET Framework and modern .NET versions.
• Deep experience with WPF, XAML, MVVM, desktop application architecture, and multithreading.
• Buy-side investment technology experience, particularly in one or more of the following areas: Portfolio Management Systems (PMS) , Order Management Systems (OMS), Execution Management Systems (EMS), Front-office trading applications, Fixed income, equities, FX, derivatives, swaps, options, TRS, or CDS workflows
• Hands-on DevExpress experience, including complex grids and performance-sensitive user interfaces.
• Experience designing and implementing RESTful APIs using ASP.NET Core or equivalent technologies.
• Python development experience for services, automation, analytics, or AI-related components.
• Strong SQL Server development and performance-tuning skills.
• Experience creating both web-based applications and rich desktop/fat-client applications.
• Practical expertise in profiling, diagnostics, memory management, performance tuning, and production troubleshooting.
• Experience with Git, automated testing, CI/CD, and Azure DevOps or similar engineering platforms.

Nice to have

• React, Angular, or comparable modern web framework experience.
• MongoDB and data-access modernization experience.
• Microservices, modular monolith, event-driven, or message-based architecture experience.
• Microsoft Azure, containerization, Kubernetes, and enterprise API management experience.
• Experience integrating LLMs, AI assistants, retrieval-augmented generation, tool-calling, or enterprise AI gateways.
• Familiarity with application security, data entitlements, auditability, and regulated environments.