Top Principal Software Engineer Jobs in Chicago, IL

Develop and deploy Python data pipelines and business data objects for applications. Design software solutions, implement source-to-target mappings, build CI/CD pipelines, and perform unit and integration testing. Resolve complex technical issues, interpret engineering requirements, maintain software quality standards, and promote team improvement. The role requires expertise in software development, architecture, testing, AWS, Snowflake, Git, and AI-assisted development tools.

As a Senior Principal Engineer, you'll define and drive the technical strategy for customer experience platforms, lead architectural decisions, and mentor engineering teams to enhance customer and agent experiences.

Design, build, deploy, and maintain resilient, scalable production systems for Toast’s retail customers. The role sets long-term technical architecture and strategy, communicates technical direction, mentors senior engineers, improves engineering productivity, diagnoses performance issues, and drives initiatives amid ambiguity. Engineers collaborate directly with retail customers, visit stores, understand operational workflows, and use AI tools to improve development velocity and quality.

Design, evolve, and optimize Scala-based, low-latency trading services. Lead architecture for scalability and performance, tune JVM/Akka systems, enhance observability, ensure security and regulatory compliance, and mentor junior engineers while collaborating cross-functionally to support 24x7 high-volume trading.

Lead architecture and technical execution for Toast’s Payroll and Team Management products. Own authentication, authorization, and organizational hierarchy across a multi-tenant SaaS platform. Drive high-scale, full-stack initiatives, modern agentic development practices, integrations, technical strategy, quality standards, deployment practices, and cross-functional collaboration. Mentor engineers across teams and leverage AI tools and LLM integration to improve software development velocity and quality.

Lead design and build of production-ready cloud and AI systems, prioritize security and reliability, ship solutions quickly using modern engineering practices, collaborate with cross-functional teams, mentor engineers, drive customer adoption, and deliver reusable assets and end-to-end complex deliveries.

Lead architecture, design, and delivery of PET product features; write production full‑stack code; champion testing, observability, CI/CD and operational readiness; mentor engineers and collaborate with product to shape technical roadmap.

Lead design, build, deployment, and operation of highly resilient, high-throughput configuration and publishing systems. Define long-term architecture and strategy, mentor senior engineers, diagnose and fix performance bottlenecks, and leverage AI tools to improve engineering productivity and platform capabilities.

Lead development of core client systems and engine-level infrastructure in Unity/C#. Diagnose and fix cross-cutting performance issues, upgrade third-party SDKs, evolve build tooling, produce design docs, scope multi-week infrastructure initiatives, mentor engineers, and drive profiling, optimization, and architecture changes to enable future features.

Leads the strategic direction of backend and full-stack engineering, architects scalable distributed systems and microservices, and drives modernization, reliability, security, and performance initiatives. Designs APIs, data architectures, pipelines, infrastructure, and observability practices; delivers customer-facing service improvements; establishes engineering standards; and mentors engineers. Collaborates across product and technical teams to make architecture and business trade-offs and lead large-scale initiatives from vision through production.

Leads the design and implementation of enterprise observability, AIOps, distributed architectures, cloud platforms, and software engineering solutions. Evaluates emerging technologies, guides architecture roadmaps, manages vendor governance, leads modernization and migration initiatives, and develops automation to improve system reliability and reduce detection and resolution times. The role also manages and coaches geographically distributed engineering teams while partnering with executive, cloud, SRE, and platform stakeholders.

Provides hands-on technical leadership for Pantheon’s P1 zero-to-one product and company-wide engineering strategy. Owns architecture across real-time collaboration, APIs, data, publishing, integrations, and developer experience; establishes reliability, security, observability, and delivery standards; guides build-versus-buy decisions; mentors senior engineers; partners with product, design, security, infrastructure, and customers; and contributes code to validate architecture and unblock critical initiatives.

Lead architecture and roadmap for Azure PostgreSQL systems; design and review scalable, maintainable database engine features (query processing, storage, transaction logging, recovery, versioning, IO, scale-out). Influence coding standards and run code reviews, write proof-of-concept or production code, contribute to open-source PostgreSQL/Linux, and participate in rotational on-call operations.

Design, develop, code, test, document, and coordinate software systems and applications. Responsibilities include modeling, requirements analysis, automated testing, software system testing, design reviews, effort estimation, and participation in formal implementation activities while meeting quality, time, and cost constraints.

Lead the architecture, technical strategy, and roadmap for Microsoft's Windows ML compiler stack. Design high-performance compiler infrastructure, execution engines, optimization frameworks, and developer tools supporting CPU, GPU, and NPU workloads. Drive NPU enablement, graph optimization, scheduling, memory management, code generation, and hardware abstraction. Partner with silicon vendors and internal teams, influence AI hardware and platform strategy, lead cross-team initiatives, and mentor engineers developing on-device and generative AI capabilities.

Leads full-stack architecture and development across React, C#/.NET, WPF, APIs, and real-time systems. Owns integration, contract, and end-to-end testing across multiple financial products, embedding automated tests into CI/CD release gates. Implements secure communications, optimizes performance, guides architectural decisions, uses AI coding assistants throughout the SDLC, resolves cross-product issues, collaborates with product teams, and mentors engineers.

Lead legacy application assessments and modernization strategy for U.S. Air Force systems. Own architectural decisions, technical direction, and test strategy while collaborating with government engineers, vendors, product managers, researchers, and designers. Promote secure, compliant, agile engineering practices; coach government teams; evaluate technical environments; communicate recommendations; and demonstrate modern AI-assisted development practices. The role is fully remote, requires U.S. citizenship and CAC eligibility, and involves occasional quarterly travel to Air Force bases.

Lead end-to-end design and delivery of AI-infused, enterprise full-stack applications on Azure. Architect resilient solutions, build Copilot/agentic features, enforce engineering best practices, mentor engineers, collaborate with PM/UX teams, ensure quality/reliability, and support production services and integrations.

Design and implement PostgreSQL internals, indexing, query engine extensions, and storage-layer features to support large-scale document workloads on Azure. Profile distributed systems, tune performance, collaborate with open-source communities, conduct design/code reviews, and drive cross-team alignment for mission-critical database features.

Leads the technical vision, architecture, and execution of AI performance, framework, benchmarking, and developer-productivity initiatives. Drives cross-team architecture, resolves complex systems trade-offs, mentors technical leaders, and contributes hands-on through prototyping, implementation, reviews, debugging, observability, and automation. Delivers measurable improvements in model onboarding speed, runtime performance, reliability, hardware utilization, and Azure capacity efficiency across models, frameworks, compilers, runtimes, systems, services, and hardware.

Lead the architecture and technical direction of large-scale Azure cloud infrastructure and machine learning platforms. Design distributed systems for model training, inference, data processing, and platform services; improve compute efficiency, reliability, security, scalability, and observability; guide Kubernetes and AI workloads in production; support MLOps practices; establish engineering standards; and mentor engineers across teams.

Lead the architecture, design, and implementation of core MarkLogic database features using C++. Build scalable, fault-tolerant distributed systems; optimize performance; debug complex server-side issues; and mentor engineers. Collaborate with product, development, QA, and documentation teams to deliver secure, high-quality database capabilities involving search, security, language runtimes, JavaScript integration, scalability, and reliability.

Own cross-team, platform-level engineering initiatives end-to-end: architecture, migrations, observability, on-call, and customer outcomes. Drive AI-native tooling and agentic AI adoption, mentor senior engineers, and set technical standards across teams.

Lead the architecture and evolution of managed Kubernetes and cloud-native services. Provide cross-team technical oversight, standardize platform practices, integrate open-source technologies, improve scale, performance, security, and operational efficiency, and mentor engineering teams. The role requires expertise in Kubernetes-based platforms, container runtimes, cloud-native architectures, and Go, Python, or Bash.

Designs, implements, integrates, and architects Unreal Engine technology for high-fidelity scene simulation, virtual hardware, and embedded software test automation. Develops mission-critical software using C++ and scripting languages, with applications in computer graphics, scientific visualization, image processing, and video game engines. Collaborates in an Agile environment using automated testing, continuous integration, and version control. Requires U.S. citizenship and an interim Secret clearance before starting, with eligibility to obtain and maintain a DoD Secret clearance.