Senior Backend Engineer

About the RoleWe are looking for a Senior Backend Engineer with deep expertise in building, scaling, and securing production-grade backend systems. You will own the backend of a complex, multi-module SaaS platform covering CRM, payroll, ERP, financial management, and AI-powered automation workflows.We are not looking for a traditional developer. We want someone who works smart — uses modern AI development tools as a core part of their workflow, ships with confidence, and takes real ownership over what they build.ResponsibilitiesDesign, build, and maintain scalable backend services and APIs across multiple product domainsOwn database architecture, schema design, query optimisation, and migration managementDesign and manage background job processing, queue architecture, and worker systemsIdentify and resolve performance bottlenecks, security vulnerabilities, and reliability issuesSet up and maintain observability — structured logging, error monitoring, and alertingDefine and enforce backend engineering standards, patterns, and best practicesCollaborate with frontend and infrastructure on system integration and deploymentRequired Skills4+ years of production backend engineering with Node.js and TypeScriptDeep PostgreSQL knowledge — schema design, indexing strategies, query analysis, migrationsStrong understanding of distributed systems — queues, async patterns, concurrency, consistencyProduction experience with NestJS and/or ExpressBackground job processing — BullMQ, Bull, or equivalent queue systemsRedis — caching, pub/sub, session managementAPI design — REST, WebSockets, real-time communication patternsSecurity — authentication, authorisation, input validation, secrets managementPerformance optimisation — profiling, connection pooling, query tuning, caching strategiesObservability — structured logging (Pino or equivalent), error tracking (Sentry or equivalent)Testing — unit and integration testing for backend servicesAI development tools — Claude, Cursor, Codex, or equivalent (must use these daily, not occasionally)Nice to HaveCloud platform experience — GCP, AWS, or Azure (comfortable operating cloud-native applications)Docker and containerised deploymentsAI / LLM API integration experienceFrontend familiarity — the platform is built on React and Next.jsWhat We're Looking ForDeep backend instincts — you think about failure modes, race conditions, and data integrity by defaultYou have operated systems under real load and know what breaks and whySecurity-conscious — you don't need to be reminded to sanitise inputs or rotate secretsAI-native — you use Claude, Cursor, Codex, or similar tools as a natural part of how you work, not as a noveltyOwnership mentality — you see things through from design to deployment to monitoringClear communicator — you can explain technical tradeoffs to both engineers and non-technical stakeholdersSelf-directed — you can take a problem statement and drive it to a solution independentlyComfortable in large, complex codebases without needing everything to be perfectly clean firstNot a traditional 9-to-5 developer — you're curious, keep up with what's changing, and apply itHow to ApplyWe evaluate on real work, not CVs. Please share:GitHub profile, live products, Upwork profile or open source contributions — show us what you have builtA brief note on the most complex backend system you have worked on — what it was, your role, and the outcomeExamples of how you use AI development tools in your day-to-day engineering workAnything in this description outside your current experience and how you would close the gap