<p><em>At Similarweb, we are revolutionizing the way businesses interact with the digital world by revealing to them everything that happens online. </em></p> <p><em>Our unique data and solutions empower thousands of customers globally, including industry giants like Google, eBay, and Adidas, to make game-changing decisions that drive their digital strategies.</em></p> <p><em>In 2021, we went public on the New York Stock Exchange, and we continue to reach new heights! Come work alongside Similarwebbers across the globe who are bright, curious, practical, and good people.</em></p> <p><strong><br>Why is this role so important at Similarweb?</strong></p> <p>AI is transforming how Similarweb operates, but scaling it requires a robust, production-grade foundation. Instead of every product and internal engineering team reinventing infrastructure, we are building a centralized, high-throughput AI Platform.</p> <p>As a <strong>Senior Backend Engineer (AI Platform),</strong> you will design and implement the resilient core services powering our AI ecosystem: high-concurrency agent runtimes, distributed tool and data pipelines, low-latency model gateways, and real-time evaluation and observability systems. Your internal customers are teams across the whole company, including engineers, data scientists, back office and product teams - your systems will turn AI prototypes into scalable, fault-tolerant production services deployed across Similarweb. You will not build isolated AI features; you will build the scalable platform layer that handles state management, routing, and system reliability for dozens of high-throughput AI workflows.<br><br></p> <p><strong>What will you be doing?</strong></p> <ul> <li><strong>Core Systems Design:</strong> Architect and build the high-availability agent platform - focusing on distributed orchestration, state/memory persistence layer performance, event-driven execution, and a high-performance Python SDK.</li> <li><strong>API & Integration Architecture:</strong> Design and operate scalable tool and connector services, including standardized Model Context Protocol (MCP) servers, gRPC/REST endpoints, and secure wrappers for Similarweb data stores, internal microservices, and external APIs.</li> <li><strong>Low-Latency Model Infrastructure:</strong> Build low-latency model gateways, connection pooling, automated failover routing, semantic caching layers, and rate-limiting infrastructure.</li> <li><strong>Security & Governance:</strong> Implement zero-trust security patterns at the platform layer: fine-grained access control (RBAC/ABAC), isolated data boundaries, PII detection pipelines, and high-throughput audit logging.</li> <li><strong>Reliability & Performance Engineering:</strong> Optimize distributed execution to ensure strict SLA compliance, minimizing end-to-end latency and compute costs while ensuring system observability through distributed tracing and custom metrics.</li> </ul> <p><strong>This is the perfect job for someone who brings:</strong></p> <ul> <li><strong>5+ years of software engineering experience</strong> in backend development, with advanced proficiency in Python and backend system architecture.</li> <li><strong>Strong system design background:</strong> Experience building asynchronous microservices, REST/gRPC APIs, distributed state management, containers, and CI/CD pipelines.</li> <li><strong>AI Framework Engineering:</strong> Hands-on experience building or extending agentic runtime frameworks (LangGraph, LangChain).</li> <li><strong>Production Operations:</strong> Solid grounding in database architecture (SQL, NoSQL, Vector Databases), caching strategies (Redis), and event-driven messaging (Kafka/RabbitMQ).</li> <li><strong>Cross-functional Collaboration:</strong> Proven ability to design clear API contracts and developer-facing platform tooling for other engineering teams.</li> </ul> <p><strong>Preferred Skills:</strong></p> <ul> <li><strong>Infrastructure & Cloud:</strong> Hands-on experience with AWS, Kubernetes, Terraform/CloudFormation, and modern cloud-native deployment patterns.</li> <li><strong>LLMOps & System Optimization:</strong> Expertise in cost and latency optimization, dynamic model routing, load balancing, and capacity planning for high-volume LLM workloads.</li> <li><strong>Data Engineering & RAG:</strong> Experience designing scalable retrieval-augmented generation (RAG) pipelines over large-scale, heterogeneous data lakes.</li> <li><strong>Observability & Monitoring:</strong> Experience setting up distributed tracing and custom APM dashboards for backend services.</li> </ul> <p><strong>Why you’ll love being a Similarwebber:</strong></p> <ul> <li data-stringify-indent="0" data-stringify-border="0"><strong data-stringify-type="bold">Impact </strong><strong data-stringify-type="bold"><span class="c-emoji c-emoji__medium c-emoji--inline" data-qa="emoji" data-sk="tooltip_parent"><img style="max-width: 100%;" src="https://a.slack-edge.com/production-standard-emoji-assets/14.0/apple-medium/1f60e.png" alt=":sunglasses:" data-stringify-type="emoji" data-stringify-emoji=":sunglasses:"></span></strong><strong data-stringify-type="bold">:</strong> Work with the world’s leading digital intelligence platform and make a real differ