Top C# Jobs in Chicago, IL

Develop and test high-performance C++ applications for trading platforms. Collaborate with traders and experienced engineers to translate requirements into efficient solutions, while monitoring, profiling, and troubleshooting systems for reliability and stability. The role provides mentorship and exposure to the complete trading-system development lifecycle, including production support, performance tuning, multithreaded programming, and real-time systems.

Leads complex software optimization initiatives from design through implementation and validation. Builds cloud-native services, data pipelines, dashboards, automation, and AI-enabled forecasting solutions. Analyzes cloud costs, resource utilization, reliability, capacity, and engineering productivity while partnering with Engineering, Finance, Product, Data, Platform, and SRE teams. Ensures scalable and secure integrations, testing, observability, financial data quality, and measurable savings. Provides technical leadership and mentorship to junior engineers without direct people-management responsibilities.

Design, develop, optimize, deploy, and maintain high-performance market data and automated trading systems. Process raw market data feeds, implement CME and Cboe exchange protocols, and optimize concurrency, throughput, scalability, and ultra-low-latency performance. Collaborate with traders, quantitative researchers, analysts, and engineers while supporting critical applications, automated testing, peer reviews, and best practices. Coach junior engineers and take ownership of projects from design through maintenance.

Develop cross-platform C++ and Qt software for network device discovery, monitoring, and data collection across Windows and Linux. Build high-performance, concurrent, asynchronous systems that communicate with thousands of devices using SNMP, SSH, ICMP, WMI, and related protocols. Own testing, troubleshoot issues across application, operating-system, and network layers, optimize reliability and performance, and collaborate with backend, UI, QA, and product teams.

Ten-week paid software engineering internship developing, testing, and deploying C++ solutions for a proprietary trading platform. Interns work with large datasets, network programming, multithreaded applications, AI coding tools, and cross-functional technologists and researchers. The role includes mentorship, complex problem-solving, collaboration, and opportunities for full-time employment after graduation.

Develop and test high-performance C++ applications for trading platforms. Collaborate with traders and senior engineers to translate requirements into efficient solutions, while monitoring, profiling, troubleshooting, and improving system reliability. Gain hands-on experience across the full trading-system development lifecycle in an on-site, highly collaborative environment.

Build and optimize low-latency C++ systems for market data processing, exchange connectivity, and order execution. Analyze performance across application, memory, CPU, networking, and operating-system layers. Collaborate with traders, FPGA engineers, and infrastructure teams, while owning production systems through design, testing, deployment, and real-time support.

Design, develop, and maintain high-performance C++ trading platform applications. Partner with traders and quantitative researchers to translate business needs into efficient technical solutions. Lead profiling, performance optimization, testing, code review, and release improvements while owning features from design through production support.

Develop scalable C++ software that defines and enforces endpoint behavior across millions of managed Windows endpoints. Responsibilities include implementing features, improving platform performance, shipping production code, designing new systems, writing architecture documents, defining subsystem contracts, and collaborating with server, UI, product, and design teams. The role requires deep Windows systems and kernel-driver expertise, with preferred experience in WHQL, minifilter or WFP drivers, macOS Endpoint Security, and Linux kernel development.

Develop and maintain core components of a modern digital auction platform using C# and .NET Core. Responsibilities include designing data models, building RESTful APIs, integrating legacy and third-party systems, developing Azure DevOps CI/CD pipelines, troubleshooting performance issues, conducting code reviews, documenting best practices, and collaborating with product managers and multiple engineering teams.

Develop and maintain desktop, web, database, and middleware components using C#, HTML5, JavaScript, SQL Server, and RESTful APIs. Work includes real-time processing, concurrency, asynchronous and multithreaded programming, WinForms, web services, security, database scripting, and migration from Flex to AngularJS. Collaborate within an agile team, support build and testing infrastructure, maintain legacy code, and contribute to architectural improvements.

Build and lead high-performance browser features in modern C++ and Chromium, including tracker blocking, subscription integrations, and responsiveness monitoring. Own complex projects from proposal through post-mortem, solve ambiguous technical problems, make architecture decisions, collaborate asynchronously with product and design, and use metrics to evaluate outcomes in a large-scale consumer codebase.

As a Sr. Software Engineer at Bloomerang, you will lead technical direction, mentor engineers, and enhance SaaS solutions while utilizing .NET and AI tools. You will ensure scalable, maintainable applications, advocate for Agile workflows, and focus on quality outcomes in software development.

Design, implement, test, and modernize backend services and integrations (TypeScript/Node.js and C++). Lead large projects, write technical specifications and API contracts, enforce coding standards, coach engineers, and drive legacy-to-modern migrations within online banking and core systems.

Build software, data pipelines, dashboards, and automation for cloud cost visibility, infrastructure efficiency, reliability, engineering productivity, and financial accountability. Analyze workloads and billing data, implement AI- and analytics-enabled forecasting and anomaly detection, develop cloud-native services, and support capacity planning, cost allocation, and optimization. Collaborate with Engineering, Finance, Data, Platform, SRE, Architecture, and Product teams while testing, troubleshooting, documenting, and communicating recommendations and business value.

Build and maintain scalable, cloud-native APIs and high-value core system components using .NET and related technologies. Lead software architecture and testing discussions, enhance core offerings, collaborate cross-functionally, and ensure quality through code reviews, unit testing, functional testing, telemetry, and performance tuning. Mentor teammates and contribute to continuous technical and process improvement.

Develop and support Veeam Backup for Microsoft 365, collaborate across product development, and help plan and implement product features. The role requires strong C# expertise, knowledge of algorithms and data structures, relational database development, and public cloud experience. Familiarity with Windows, Linux, Exchange, SharePoint, Office 365, event-driven systems, and commercial software products is advantageous.

Design and develop scalable C++ software for endpoint state and control across Windows, macOS, and potentially Linux. Build reliable, multi-process systems that enforce endpoint behavior, manage local state, support IPC, and operate across millions of devices. Responsibilities include implementing features, improving platform performance, writing design documents, defining architecture and IPC contracts, and making technical decisions in an evolving, sparsely documented environment.

Develop and test systems-level C++ software that defines and enforces endpoint behavior. Initially, the engineer will own testing infrastructure and coverage for two active projects, then contribute to feature development. The role requires strong C++ fundamentals, automated testing experience, and interest in operating-system concepts such as processes, file systems, services, and APIs. Work includes learning unfamiliar systems, collaborating effectively, and supporting reliable endpoint security and management capabilities.

Design, build, and maintain data pipelines, datasets, APIs, storage systems, and research infrastructure supporting quantitative trading. Develop big data tooling for cluster and high-throughput computing, improve scalability and performance, manage data transmission between C++ and Python, and support releases, debugging, maintenance, and storage expansion. The role also involves leading technical projects and mentoring junior engineers.

Develop and enhance performance-critical C++ applications for ultra-low latency trading systems, collaborating across teams to analyze and optimize performance.

Leads and develops a software engineering team while contributing hands-on to enterprise application design, coding, testing, code reviews, production support, and technical decisions. Builds scalable solutions using C#, ASP.NET, SQL Server, and modern web technologies; partners with product and business stakeholders; supports Agile delivery, CI/CD, troubleshooting, root cause analysis, and engineering best practices. The role also includes mentoring engineers, monitoring delivery and operational metrics, and driving continuous improvement.

Join an on-site Chicago team building high-performance C++ trading systems. Design, develop, test, profile, and troubleshoot low-latency applications while collaborating with traders and senior engineers. Receive mentorship, training on markets, and exposure to production lifecycle and performance tuning.

Join an on-site Chicago team building high-performance C++ trading systems. Contribute to design, development, testing, profiling, and troubleshooting. Collaborate with traders and senior engineers, receive mentorship, and gain exposure to the full lifecycle of low-latency trading platform development.

Design, implement, and maintain C++ components for a global electronic trading platform. Collaborate on system design, perform code reviews, troubleshoot production issues, and improve system stability while participating across the software development lifecycle.