Top Staff Software Engineer Jobs in San Francisco, CA

The Principal Engineer will lead technical direction across multiple teams, design architecture for financial systems, mentor engineers, and drive multi-year transformations in the Money Group.

Lead the technical design and architecture of Gusto's Commerce Platform, mentoring engineers and ensuring service reliability while collaborating across teams.

As a Staff Software Engineer, you'll design, build, and test Gusto's core platform services, mentor engineers, and collaborate with various teams to solve complex engineering problems.

As a Senior or Staff Deployed Software Engineer, you will design and build software solutions, collaborate with teams, and drive technical strategy while engaging with customers to solve complex problems.

Lead full-stack development of the signup-to-activation experience, inventing and shipping 0-to-1 AI-driven onboarding features across web, messaging channels, and third-party AI assistants. Collaborate with product, design, and data, mentor engineers, scope rapidly, and measure/iterate to improve activation metrics.

The Senior Staff Software Engineer will lead the architecture and implementation of AI-powered developer tools and workflows in a cloud environment. Responsibilities include mentoring, driving innovation, managing project delivery, and fostering a culture of continuous improvement.

Lead technical direction, design, build, and operate Snap's large-scale service and compute infrastructure. Drive platform roadmaps, reliability, observability, CI/CD, and developer experience. Act as hands-on staff tech lead across cross-functional initiatives, mentor engineers, and shape infrastructure for an AI-first future.

Lead the design and evolution of predictive maintenance platform, build and scale ML-powered features, and mentor other engineers.

Lead full‑stack engineering work on tax experiences: design, build, test, and operate scalable systems for tax collection, payment, and filing. Drive technical strategy, mentor engineers, collaborate cross-functionally, prioritize long-term architecture, and apply AI tools to improve developer productivity and customer workflows.

Design, build, and harden asynchronous infrastructure and developer tooling to improve engineer productivity. Work on background jobs and async communication using Sidekiq, Kafka, and Karafka, collaborate with product engineers, and apply AI/LLMs for large-scale code migrations and faster incident resolution.

Design, build, and ship production LLM-powered features for Gusto Retirement. Implement and integrate LLMs (RAG, agents, prompting, tool loops), make pragmatic architecture decisions, collaborate with product, design, and engineering, write reliable well-tested code, and drive end-to-end execution and iteration.

Design and build scalable RL environments, create automated QA systems, and collaborate with AI researchers to improve training data efficacy. Lead and mentor junior engineers.

Lead design, build, and operation of AI-powered Growth experiences (conversational onboarding and AI-driven email). Own technical strategy for an AI Voice Agent and ACE-powered email systems, design APIs and frontend/backends, partner cross-functionally, establish applied-AI engineering patterns, measure impact, and mentor engineers to improve product quality and responsible AI use.

Lead full-stack development for employer and employee tax account systems: design reliable backend APIs and data models, build automation and agency-integration pipelines, model jurisdiction-specific compliance rules, mentor engineers, partner with product and operations, and deliver scalable, test-driven solutions that ensure tax accuracy and reliability at scale.

Lead org-wide developer experience and AI-enabled developer workflows. Identify and solve high-leverage bottlenecks across build systems, monorepo tooling, CI/CD, and test reliability. Drive standards, enable monolith-to-modular migration, embed with product teams, mentor engineers, and deliver AI-native developer tooling and adoption at scale.

As a Staff Software Engineer at Samsara, you will lead and develop a high performing team, champion company culture, and contribute to the development of IoT platform solutions.

Lead full‑stack development for Gusto's PEO Benefits product: design and build benefits shopping, plan recommendation flows, carrier integrations, automation agents, and MCP tools; scale Ruby/Rails and JavaScript/React systems; mentor engineers; drive multi‑quarter, cross‑functional projects from spec through launch and iteration; collaborate with Product, Data, Design, and Platform teams to deliver customer‑facing features.

Build and architect LLM/ML-powered systems to evaluate clinical quality, detect risk in claims, match patients to providers, and ensure trustworthy AI. Lead technical foundations, mentor engineers, ship end-to-end product features across frontend and backend, and create evaluation and observability for safe, scalable healthcare ML.

Lead technical due diligence and product/architecture evaluations for M&A in AI, cloud, and security. Scope and run POCs and sandbox tests, assess risks and integration paths, advise C-level leadership, and partner with Product, Engineering, and Security to drive transactions to close.

Lead performance architecture and optimization strategies for AI inference services, focusing on maximizing throughput and minimizing latency for advanced models. Mentor the team, collaborate on product features, and maintain expertise in GPU architectures and open-source projects.

Technical leader responsible for architecting and evolving Drata's billing and monetization platform: usage ingestion, billable metrics, pricing, entitlements, invoicing, and integrations with Finance/CRM/ERP. Design event-driven, auditable, and scalable systems, ensure operational correctness and reconciliation, lead cross-team initiatives, review architecture, troubleshoot discrepancies, and mentor engineers on financial correctness and distributed systems.

Lead architecture, build, test, and scale Gusto's iOS app and mobile infrastructure. Improve build pipelines, automated testing, release processes, and foundational services (push, accessibility, localization). Collaborate across product, design, security, and infrastructure teams; prototype, iterate, and launch customer-focused features while mentoring engineers.

Lead technical strategy and architecture for Affirm Bank's cloud, data, vendor integrations, and operational tooling. Design, build, and operate high-stakes systems end-to-end, own incident response, vendor selection, and the Bank↔Affirm Inc integration boundary. Ensure examiner-ready documentation, compliance, reliability, and observability while mentoring engineers and pushing AI-assisted engineering practices to increase velocity and product safety.

Architect, build, and optimize a full-stack platform (React frontend, Node.js backends). Lead technical decisions, design scalable APIs, improve DB performance, implement observability, enforce testing, mentor engineers, and drive cross-team technical initiatives.

Lead design and build of scalable AWS cloud-based backend services and APIs powering web and mobile customer experiences. Own end-to-end feature delivery, improve grading and authentication workflows for scale and reliability, leverage AI tools to accelerate development, and provide technical leadership and mentorship across teams.