Senior Backend Engineer

Senior Backend Engineer (Infrastructure & AI Platform)FlexAI is looking for a Senior Backend Engineer (Infrastructure & AI Platform) with deep Golang expertise to architect and build the core backend systems powering our next-generation AI compute and PaaS platform. This role sits at the intersection of distributed systems, cloud infrastructure, and AI platform engineering — enabling large-scale model training, inference, and orchestration across heterogeneous compute. This is not a traditional backend role; you will be building platform-grade systems that support AI runtimes, scheduling, resource orchestration, and multi-tenant cloud infrastructure.As a Senior Backend Engineer, you'll drive backend architecture, scale platform services, and build high-performance infrastructure components that power AI workloads in production environments — influencing how the platform evolves from Beta to enterprise-grade deployment. Expect high ownership and technical autonomy in a research-driven, deep-tech environment — not SaaS CRUD apps.This position is In-Person and located at our San Jose, CA Office.Core Platform & Infrastructure BackendArchitect and develop high-performance Golang services for FlexAI's AI PaaS and infrastructure platformBuild internal APIs powering model deployment, job scheduling, and compute lifecycle managementDevelop components interfacing with GPU/compute infrastructure and AI runtimesDistributed Systems & ScalabilityDesign and scale microservices and event-driven systems for high-throughput AI workloadsOptimize for low latency, high concurrency, and fault toleranceImplement service-to-service communication (gRPC/REST, message queues, async pipelines)Drive reliability, observability, and resilience across servicesAI Platform IntegrationCollaborate with AI/ML and Runtime teams to integrate systems with training pipelines, inference infrastructure, experimentation workflows, and dataset/artifact managementEnable orchestration across cloud and on-prem environmentsBuild abstractions that simplify AI infrastructure consumptionCloud-Native & Platform EngineeringDesign cloud-native, Kubernetes-native servicesWork with DevOps/SRE on CI/CD, deployment automation, and scalabilityContribute to architecture decisions for multi-region, multi-cloud infrastructureImprove monitoring, logging, and diagnosticsTechnical LeadershipLead architecture reviews and set engineering standardsMentor engineers and guide complex problem-solvingDrive long-term roadmap for backend infrastructure and AI platform capabilitiesPartner with Product, Runtime, and Infra leadership to translate requirements into scalable systemsTech Stack (Indicative)Languages: Golang (Primary), Python (Secondary)Infrastructure: Kubernetes, Docker, Cloud (AWS/GCP/Azure)Architecture: Microservices, gRPC, Event-driven systemsData: SQL + NoSQL databases, caching, streaming systemsObservability: Prometheus, Grafana, OpenTelemetry (or similar)What You'll Need to Be SuccessfulCore Engineering:5+ years of Backend or Infrastructure Engineering experienceExpert-level proficiency in Golang (must-have, heavy hands-on)Strong experience building production-grade distributed systemsProven track record on infrastructure platforms, PaaS, or deep-tech systemsInfrastructure & Systems:Deep understanding of cloud-native architectures and containerized environmentsStrong experience with Kubernetes, Docker, and cluster orchestrationFamiliarity with compute scheduling, resource management, or platform runtimes is a strong plusDatabases & Data Systems:Experience with distributed databases (PostgreSQL, Cassandra, DynamoDB, etc.)Strong understanding of caching, queues, and streaming systems (Redis, Kafka, etc.)AI / Platform Exposure (Highly Preferred):Experience on AI/ML platforms, model infrastructure, or data platformsFamiliarity with ML pipelines, inference systems, or GPU-backed workloadsExposure to PyTorch, TensorFlow infrastructure, or model serving systems is a plusIdeal Candidate Profile (Who Will Thrive Here)Infra-first backend engineers (not just API developers)Background in AI infra, cloud platforms, developer platforms, or deep-tech systemsStrong systems thinkers who enjoy low-level performance, scalability, and architecture challengesStartup-minded builders comfortable in ambiguous, high-ownership environmentsWhat We OfferCompetitive salary and benefits packageWork on cutting-edge AI infrastructureBuild products used by developers and enterprisesHigh ownership, fast execution, real impactCollaborative, high-caliber team