Top Principal Software Engineer Jobs in San Francisco, CA

Principal Software Developer responsible for designing, developing, and scaling distributed, high-throughput software systems. The role delivers features, improves reliability, identifies bottlenecks, leads system migrations from monoliths to microservices, and works across the technology stack. Responsibilities include architectural design, cloud engineering, technical leadership, mentoring developers, communicating technical decisions, and using AI and automation tools to improve engineering outcomes.

Leads architecture and hands-on development for AI frameworks, performance systems, benchmarking, and developer tools. Investigates issues across models, compilers, runtimes, services, and accelerator hardware; improves model onboarding, runtime performance, reliability, hardware utilization, and Azure efficiency. Establishes scalable measurement and observability capabilities, influences cross-team technical strategy, delivers production solutions, and mentors engineers while advancing engineering quality and maintainability.

Lead architecture, development, scaling, and reliability for SingleStore Helios, a multi-cloud SaaS platform. Design Kubernetes operators, controllers, networking, routing, and distributed control planes across AWS, Azure, and GCP. Build resilient Go and Python systems, support AI and vector workloads, resolve complex Tier-3 production incidents, and maintain compliance controls. Mentor engineers, author architecture documents, and influence cross-functional technical strategy.

Lead architecture and long-term technical direction for Docker Hardened Images (DHI). Define platform standards for image and Helm chart hardening, supply-chain posture (SBOM, SLSA, signing), and distribution. Drive cross-functional roadmaps, resolve ambiguous packaging/security problems, influence upstream OSS, mentor senior engineers, shape test and tooling strategy, and participate in on-call incident response.

Lead the technical direction and production development of defensive agents for an autonomous cybersecurity platform. Design durable agent execution, authorization and multi-tenant isolation, third-party security-control connectors, distributed workflows, and explainable observability. Translate product goals into roadmaps, partner with AI researchers and Product, review designs and code, mentor engineers, and maintain production services. The role requires deep experience with agentic or LLM-backed systems, cloud platforms, distributed systems, SQL, security controls, and operational ownership.

Own the technical vision and architecture for ServiceTitan’s iOS and Android mobile platform. Design scalable, reliable, secure, and high-performing systems; modernize monolithic codebases; improve observability, developer productivity, CI/CD, testing, and release processes. Mentor engineers, influence mobile strategy, define success metrics, support recruiting, and collaborate with cross-functional stakeholders. The role is approximately 60% development and requires expertise in native mobile development, performance engineering, modular architectures, and cloud-supported mobile backends.

Own the architecture and development of Databricks-based data platform frameworks and infrastructure. Build configuration-driven ingestion, reusable data protection libraries, infrastructure-as-code foundations, deployment standards, observability, and reliability capabilities at billion-row scale. Lead proofs of concept, architectural decisions, cross-functional delivery, technical reviews, mentoring, and engineering standards while partnering with data, governance, security, and source-system teams.

Build secure, compliant embedded-finance platform products, primarily in Java. Develop scalable, performant, maintainable software; write robust unit and integration tests; understand customer needs; document solutions; and collaborate across company domains. The role also requires applying AI-powered development tools throughout the software lifecycle and may involve cloud, containerization, data, payment-platform, and AI-agent technologies.

Refactor and migrate legacy U.S. Air Force web applications to a DoD software factory with minimal downtime. Build secure, tested software; identify technical debt; improve CI/CD and engineering practices; communicate technical tradeoffs to government stakeholders; and coach government engineers and military developers. The role works remotely with cross-functional teams and includes occasional travel to Air Force bases.

Leads hands-on development of production software while owning application and service architecture. Diagnoses systemic issues across components, coordinates integration efforts, and improves reliability, performance, and incident response. Builds scalable full-stack SaaS applications using Java, Spring Boot, TypeScript, Node.js, and React. Applies AI-assisted development tools, mentors engineers through influence, and makes technical decisions that balance maintainability, business needs, and client impact.

Principal Software Engineer leading architecture, development, and technical strategy for complex software platforms. The role requires designing scalable and secure systems, guiding engineering standards, mentoring engineers, resolving complex technical issues, and partnering with product, laboratory, and bioinformatics teams. Responsibilities include software architecture, React and .NET development, database optimization, REST APIs, distributed systems, DevOps, regulatory compliance, and long-term technology roadmaps supporting clinical and genomic workflows.

Build and operate production-quality AI framework, runtime, benchmarking, performance, automation, observability, and developer-tooling systems. Optimize large language model training and inference across GPUs and Microsoft hardware, diagnose cross-stack reliability and performance issues, and improve model onboarding, hardware utilization, Azure efficiency, and deployment speed. Senior engineers own major components and projects; Principal engineers define technical direction, architecture, and multi-release strategy while leading cross-team initiatives and mentoring technical leaders.

Lead architecture, implementation, and delivery of R&D platform infrastructure (cloud, Kubernetes, IaC). Provide technical leadership and mentorship, build AI-native developer tooling, partner with scientists to translate needs into production-grade platform capabilities.

Lead technical direction and engineering outcomes for large-scale advertising platforms. Design and operate highly reliable distributed backend systems, make architecture and technology trade-offs, align engineering and product leaders, improve delivery and reliability practices, guide major technical initiatives, and mentor senior engineers and emerging technical leaders across the organization.

Lead technical direction and engineering outcomes for large-scale advertising platforms. Design and operate reliable distributed backend systems, guide architecture and risk management, establish organization-wide engineering standards, and align technical priorities with business goals. Mentor senior engineers and emerging technical leaders while improving delivery, reliability, and engineering leverage across multiple teams. The role requires deep backend expertise, organizational influence, and experience operating high-reliability systems at scale.

Principal Software Engineer responsible for cross-cutting architecture, technical roadmap direction, and delivery quality. The role involves developing APIs, databases, UIs, and libraries with C# or JavaScript/TypeScript; guiding AI-assisted development; establishing testing and verification practices; mentoring engineers; improving tooling and workflows; collaborating cross-functionally; estimating work; and participating in on-call support. The position is fully remote with occasional travel.

Serves as a principal technical leader across Integrations, Workflows and Orchestration, and Data Management. Designs and modernizes distributed, event-driven backend systems; writes production code; resolves reliability issues; leads incident response; establishes engineering practices; shapes technical roadmaps; evaluates build-versus-buy decisions; documents architecture; mentors engineers; and influences teams and stakeholders without direct authority.

Leads technical direction for the Partner Services engineering area while remaining hands-on with mission-critical financial systems. Owns architecture roadmaps, ADRs, observability, reliability, security, technical investment, OKRs, and KPIs across multiple teams. Leads major incidents, drives AI-native engineering practices, partners with product and executive stakeholders, participates in architecture governance, and mentors engineers at every level. The role requires strong payments or banking familiarity, executive communication, and extensive technical leadership experience.

Leads technical strategy and architecture for a multi-team billing engineering workstream supporting payments, banking, treasury, and financial settlement. Remains hands-on while owning architecture roadmaps, ADRs, reliability, observability, security, AI-native engineering practices, technical investment, and business outcomes. The role partners with senior engineering and product leaders, manages high-stakes incidents, strengthens engineering maturity, and mentors engineers at every level.

Provides technical leadership for Azure SQL databases supporting a highly available Azure service. Responsibilities include database performance tuning, reliability and capacity planning, schema changes, data migrations, observability, incident response, root cause analysis, operational automation, and technical strategy. The role partners with software engineers, SREs, and architects to improve scalability, durability, cost efficiency, and long-term service reliability across teams.

Founding engineer responsible for architecting and building core product components, writing scalable Python code, designing and maintaining AI/ML infrastructure, implementing testing and CI/CD best practices, shipping backend production systems, collaborating on product roadmap, and mentoring future engineers.

Lead technical direction and major multi-team projects for Chainguard Containers. Design and operate secure container build pipelines, registries, distribution systems, and adoption tooling. Remain hands-on with Go development, architecture, code review, observability, and on-call operations. Form roadmaps with product and engineering leaders, make product-level trade-offs, mentor senior engineers, collaborate across teams, contribute to open-source and industry standards, and establish safe AI-assisted engineering practices.

Provides senior technical leadership across engineering teams by shaping architecture, guiding complex software development, mentoring engineers, and driving scalable, secure, and reliable solutions. Responsibilities include hands-on coding, design reviews, API and system architecture, CI/CD and tooling improvements, cross-team technical alignment, project leadership, and partnership with product and design stakeholders. The role is remote with quarterly travel to Tampa, Florida.

Provides principal-level technical leadership across engineering teams, shaping architecture, engineering standards, scalable software solutions, and delivery practices. The role combines hands-on software development with design reviews, technical decision-making, mentoring, CI/CD and platform improvements, system reliability, and cross-team collaboration. It also partners with product and design stakeholders and may lead high-impact initiatives. Remote work is available with required quarterly travel to Tampa, Florida.

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.