Top Principal Software Engineer Jobs in Los Angeles, CA

Design and scale critical, highly-available services; set technical direction across teams; apply best practices for availability, scalability, cost, and operational excellence; leverage AI tools and high-velocity workflows; mentor engineers and solve ambiguous, company-wide technical problems.

The Principal Software Engineer will design and implement systems for the advertiser experiences at Snap, lead technical vision, mentor engineers, and innovate on creator marketplace products.

Design and build next-generation ads formats, backend infrastructure, and scalable distributed systems. Lead technical direction, collaborate across teams to define product requirements, experiment, analyze and optimize ad performance, and ensure availability, scalability, operational excellence, and cost management. Mentor engineers and apply AI tools and high-velocity workflows to deliver production-ready systems.

The Principal Software Engineer will design automated ad serving systems, lead technical direction, collaborate with teams, and mentor engineers.

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.

Lead long-term technical strategy and execution across multiple teams, architecting and evolving foundational frontend/backend systems and platforms at massive scale. Drive AI/ML adoption, solve ambiguous, high-impact problems, remain hands-on in critical system design and implementation, and align senior leaders on roadmaps and engineering standards.

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.

Lead design and build of scalable backend systems and data platforms; own architecture and production deployments; improve reliability, performance, and observability; mentor engineers and collaborate with Product, Data Science, SRE, and Security.

Lead and execute cross-team initiatives to improve developer experience: build production AI integrations and developer tools, define build/release standards, eliminate CI/source-control bottlenecks, and drive technical strategy and operational excellence across Riot.

Design, develop, test, document and debug software and systems; collaborate with multidisciplinary teams and hardware engineers; develop compilers/utility programs, ensure software standards, and provide solutions to technical problems. Work is on-site and may require travel up to 25%.

Lead technical strategy and architecture for data-centric solutions across programs. Oversee data acquisition, harmonization, processing, storage, analysis, dissemination, and product lifecycle. Serve as technical lead/Product Owner, define enterprise data standards, decompose backlogs, prioritize features, advise leadership on analytics opportunities, and ensure mission-focused delivery within high-clearance environments.

Lead product vision and roadmap for mission planning software; own and prioritize backlog; liaise with customers, program managers, and engineering; run demos, sprint reviews, and release planning; design and implement software systems, collaborate with hardware teams, analyze user needs, ensure software standards, and apply Agile/CI/CD and DevOps practices.

Lead and mentor software engineers to modernize research codebases using modern C++ (17+), develop CI/CD and MLOps infrastructure, design modular/high-performance software systems, ensure engineering best practices, and collaborate with architects to meet system requirements and performance goals.

Lead the DevOps team, architect infrastructure, implement CI/CD pipelines, optimize Kubernetes and Docker, and mentor engineers for high-impact projects.

Provide technical leadership and hands-on full-stack development for mission-focused, event-driven, cloud-native systems. Design architectures, integration patterns, scalable services/APIs, mentor teams, collaborate with stakeholders, and improve DevSecOps, CI/CD, observability, and software quality across multiple projects.

As a Principal Software Engineer, you will lead the architecture of AI platforms at SpaceX, focusing on scalable solutions and risk-mitigation tools, while mentoring engineers and driving cultural change.

The Principal Software Engineer will analyze, design, and implement software solutions, debugging and enhancing products for various applications while ensuring documentation and user requirements are met.

As a Principal Software Engineer, you'll develop tools for continuous integration in Starship software, enhancing collaboration and efficiency for engineers.

Design, develop, and model mission‑critical ground software for space systems. Integrate mission‑planning workflows and operational constraints, debug and integrate large distributed systems, lead task management and mentor team members, and create modular, reusable software architectures while performing software design and modeling analysis.

Develop, test, and deploy mission-planning software on Windows. Maintain CI/CD pipelines, build/test environments, installers, and automated test suites. Support formal test events, troubleshoot systems, integrate third-party hardware/software, and collaborate in Agile scrums; may act as Scrum Master and produce contract deliverables.

As a Principal Software Engineer, you will lead architectural development and implementation of complex software systems while collaborating with engineering teams across disciplines.

As a Principal Software Engineer, you'll drive the technical vision for automation frameworks, collaborate across teams, mentor others, and enhance quality standards.

Lead architecture and implementation of large-scale, elastic Pub/Sub and messaging services. Define scalable, reliable designs, mentor engineers, drive CI/CD and testing strategies, manage incidents, partner with PMs/EMs, and advance AI tooling across the SDLC to enable real-time analytics and integrations.

Lead design and implementation of full-stack, large-scale cloud platform capabilities for Microsoft Fabric. Shape architecture, build GraphQL APIs, developer tools, AI-driven experiences, participate in livesite operations, mentor engineers, and drive cross-team initiatives to deliver scalable, reliable developer-facing services.

Define next-generation graphics and compute capabilities for Direct3D and HLSL. Collaborate with GPU vendors and industry groups, influence standards, design and ship new features, and analyze and optimize workloads across modern GPU architectures.