Top Senior Backend Engineer Jobs in San Francisco, CA

Build reliable backend systems that process millions of contracts, orchestrate LLM and data-extraction pipelines, support clustering algorithms, and power highly accurate contract search and retrieval. Collaborate with lawyers and product teams to develop AI-driven legal technology in a fast-growing startup environment.

Build and launch complex backend projects, design scalable architectures, lead code reviews, resolve high-risk issues, and contribute to company-wide engineering initiatives. The role involves Java development, distributed systems, cloud platforms, databases, performance optimization, mentoring engineers, and influencing technical decisions across teams.

Build and operate Philo’s ML and LLM infrastructure, including AWS and Kubernetes platforms, GPU scheduling, model serving, inference optimization, monitoring, evaluation, experimentation, and CI/CD. The role establishes infrastructure best practices, reliability, security, scalability, and Infrastructure as Code while supporting recommendation, video classification, and agent workloads. It also involves collaborating with engineers and vendors to deploy, instrument, and manage production systems.

Architect and operate Affirm’s large-scale Amazon EKS compute platform, including cluster lifecycle, node management, autoscaling, shared components, infrastructure automation, workload safety policies, observability, cost and capacity optimization, and self-service workflows. The role drives technical strategy, mentors engineers, partners cross-functionally, and participates in on-call incident response.

Build and operate Affirm’s AI platform, including LLM and MCP gateways, agent runtimes, evaluation services, and governance controls. Design highly available backend systems, manage identity, quotas, routing, caching, reliability, observability, and security for AI workloads. Own projects from design through launch and on-call, establish engineering standards, collaborate across teams, mentor engineers, and help scale AI systems into production.

Design, build, deploy, and operate Philo’s scalable server-side ad insertion and programmatic advertising services. Develop resilient data pipelines, ad integrations, identity and measurement solutions, monitoring tools, and highly available microservices. Collaborate with ad ecosystem partners, video delivery, ad operations, data science, and business stakeholders to optimize ad delivery, reliability, performance, security, and compliance with industry standards.

Build and enforce workload safety standards across Affirm’s Amazon EKS fleet. Responsibilities include Kubernetes resource management, workload isolation, disruption handling, cluster capacity analysis, policy automation, production debugging, incident response, fleet-wide rollouts, technical leadership, mentoring, and measuring infrastructure impacts on availability, latency, risk, and cost.

Own and deliver highly available, low-latency backend identity systems supporting consumer onboarding, authentication, and verification. Lead quarterly team goals, guide engineers through ambiguous problems, collaborate with product and design partners, monitor system reliability, improve engineering standards, support on-call operations, and mentor team members. The role requires designing and launching distributed systems at scale using Python or Kotlin, AWS, MySQL, and Kubernetes.

Build and ship backend features end-to-end using Ruby on Rails and SQL. Lead complex technical projects, solve architecture challenges, establish standards, conduct meaningful code reviews, resolve high-risk bugs, document systems, collaborate across engineering teams, and mentor junior engineers.

Build and operate backend services for Slack’s enterprise productivity integrations with Google Workspace and Microsoft 365. Responsibilities include authentication and authorization flows, admin tooling, connector frameworks, analytics, experimentation, secure architecture, production support, code review, mentoring, and cross-functional collaboration.

Build and operate high-throughput backend and infrastructure services powering healthcare AI agents. Own core platform services end to end, design for concurrency and reliability, improve performance and observability, handle sensitive healthcare data, and influence architectural decisions. The role requires production experience with distributed systems, service design, debugging across services, queues, and databases, and on-site work in New York City or San Francisco.

Build and operate high-performance Python and FastAPI backend services that ingest, process, store, replay, and distribute real-time radar sensor data. Own streaming pipelines, telemetry, geospatial views, sensor coordination, and platform architecture while ensuring low latency, reliability, security, and scalability. The role also involves end-to-end production ownership and collaboration on edge computing, cloud, and defense technology systems.

Design, build, and operate reliable backend services, APIs, data models, and workflows for billing and financial systems. Improve correctness, traceability, observability, performance, and resilience across revenue-critical integrations. Collaborate with Product, Finance, Operations, Data, and engineering teams; support production systems through on-call participation; mentor junior engineers; and leverage AI technologies for engineering and operational automation.

Lead technical vision and strategy for Affirm’s Cards backend engineering organization. Architect scalable and reliable platforms, guide cross-team initiatives, champion AI adoption and engineering excellence, influence technical roadmaps, and mentor engineers through Staff level. The role requires strong architectural expertise, organizational leadership, project management, communication, and cross-functional collaboration.

Own and deliver backend lakehouse infrastructure goals, lead engineers through complex problems, and build highly available distributed data systems. Collaborate with product, design, analytics, and engineering stakeholders; define scalable technical solutions; improve code quality and engineering standards; monitor operational health; support on-call responsibilities; and mentor team members.

Own the architecture, roadmap, and production operation of GridCARE’s AWS-based data platform. Design ingestion, data models, storage, compute, APIs, distributed processing, governance, observability, and reliable serving layers for energy data. Build and operate AI coding agent teams, establish platform standards, mentor engineers, and partner with product and domain experts. The role requires hands-on backend, distributed systems, data infrastructure, ETL/ELT, AWS, and technical leadership experience.

Own backend systems for a consumer application, building customer-facing features and solving data-focused problems such as user pairing and fraud prevention. Improve engineering workflows, testing tools, deployment automation, and release velocity. Independently lead projects from concept to completion while increasing backend ownership within a fast-growing company.

Build and operate Python backend services for Oort, Loft Orbital’s mission lifecycle platform. Design APIs, integrations, and database interactions that connect infrastructure data and tools across teams. Collaborate with program management, satellite engineering, operations, and business stakeholders to translate complex processes into reliable software. Own features from design through production, apply a product mindset, incorporate user feedback, and reduce workflow complexity.

Design, deploy, and optimize Philo’s distributed video streaming infrastructure, including ingest, transcoding, packaging, delivery, RESTful services, analytics pipelines, DRM, and ad insertion. Improve platform reliability, performance, latency, security, video quality, and cost efficiency. Collaborate with content partners and internal video, advertising, client, and data teams while supporting streaming quality across new platforms. The role also involves architectural ownership, cloud operations, and mentoring.

Develop and improve core software services supporting customer intake, application screening, and information dissemination. Design distributed, microservice-based systems; identify bottlenecks; improve reliability, scalability, and business logic; and contribute to modernization and architectural decisions. Work independently across the stack, communicate technical trade-offs, mentor junior developers, and use AI and automation tools to improve engineering outcomes.

Build and evolve scalable backend systems and APIs for a large SaaS platform. Partner with Product, Design, and QA from ideation through deployment, contribute to microservices architecture, improve testing and observability, identify operational risks, and mentor teammates. The role emphasizes reliable, maintainable solutions, strong collaboration, architectural decision-making, and continuous improvement.

Build and operate reliable backend services and financial systems supporting billing, payments, payer integrations, and revenue workflows. Design APIs, data models, durable workflows, and observability practices while ensuring correctness, security, and scalability. Collaborate cross-functionally, support production systems through on-call rotations, mentor engineers, improve developer tooling, and integrate AI technologies into engineering and operational processes.

Design and scale asynchronous Python backend systems, including REST/WebSocket APIs, multi-agent LLM workflows, provider-agnostic integrations, and RAG pipelines. Own relational data models, observability, performance, CI/CD, and production deployment. Establish AI governance covering code review, provenance, licensing, security, compliance, and customer data handling. Drive ideas from concept through production while owning architecture and outcomes.

Build and improve backend product capabilities for data cataloging, agent benchmarking, and workflow automation. Own features from user problem definition through design, implementation, launch, and production support. Develop APIs, services, data models, and workflow systems; investigate performance and production issues; contribute to architecture and code quality; and collaborate with Product, Design, and Engineering. The role is hybrid, requiring at least three days weekly in San Francisco or New York City.

Design, build, and improve scalable backend systems, REST APIs, microservices, data-processing systems, and distributed job platforms. Write secure, maintainable, high-performance code; practice test-driven development; debug production issues; improve engineering standards and tooling; and participate in on-call rotations. The role requires designing highly available systems, building backend APIs, working with relational databases, and applying security best practices.