סניור מפתח Backend

At Similarweb, we are revolutionizing the way businesses interact with the digital world by revealing to them everything that happens online. Our unique data and solutions empower over 4,300 customers globally, including industry giants like Google, eBay, and Adidas, to make game-changing decisions that drive their digital strategies. 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.   We are looking for a Senior Backend Engineer to build the distributed services, data access layers, and agent orchestration behind our AI-powered products - systems that serve analytics over billions of rows and run long-lived, LLM-driven workflows in production.   What You'll Do: This role combines deep backend and distributed systems expertise with product thinking and the ability to leverage AI tools effectively across the development lifecycle. You will work closely with product, design, frontend, and dataAI teams to build reliable, performant services, while driving engineering excellence and modern development practices. Your contributions will shape the technical foundation of an AI-first product and directly influence what end users can ask of it.   What does the day to day of a Senior Backend Engineer at Similarweb look like: Your daily work will span service architecture, data access at scale, workflow orchestration, and AI-augmented development, engaging directly with the systems that power our product. Your role will include: • Design and build scalable, maintainable backend services in Python (FastAPI, Pydantic, asyncio) and TypeScript (NestJS Node.js) • Own API design, contracts, and versioning across services - including the tool surfaces (MCP) our AI agents call directly • Design and optimize data models, schemas, migrations, and query performance across transactional (PostgreSQL) and large-scale analytical stores (Firebolt, Athena, DuckDB) • Build and operate asynchronous, long-running execution: durable workflow orchestration (Temporal), queues, scheduled jobs, and event-driven processing • Integrate LLM and agent runtimes (LangGraph, MCP, model APIs) into production services behind deterministic, testable boundaries • Implement authentication, authorization, and secure service-to-service integration patterns across an internal service mesh • Build resilient upstream data-fetching layers: timeouts, retries with backoff, caching strategies, and graceful degradation when a source is slow or down • Lead backend technical decisions, code quality standards, and system architecture • Ensure system scalability, fault tolerance, and observability - structured logging, metrics, distributed tracing, and alerting th...