Lead Backend Engineer — User Services (Go)

ABFinance is a US-based firm building digital finance for the future. Our vision is to create a full financial ecosystem where digital assets, traditional finance, and everyday money management live in one seamless experience that is made available to everyone. Founded by a team of innovators, traders, and compliance professionals, our mission is to bring digital assets to the mainstream through secure, regulated products. Our flagship ecosystem combines a compliant, security-first crypto exchange serving both retail and institutional clients, alongside a Debit Card that enables everyday spending and smooth bridging between fiat and digital assets, supported by core capabilities such as spot trading and yield generation products. Role Overview Responsible for architecture design and development of user service systems including core user services, security center, notification platform, CS/CRM, and workflow. Responsibilities • Design, develop, and optimize core user services (registration / login / token management / sub-accounts) and security center; • Build and maintain a multi-channel notification platform (Email / SMS / Push / Telegram / WhatsApp) covering system and operational dual pipelines; • Develop core modules of CS/CRM systems (agent platform, ticketing, help center, AI customer service bots); • Analyze system bottlenecks, resolve complex issues, and perform performance tuning. Requirements • Bachelor's degree or above in Computer Science or a related field; • 5+ years of backend development experience, with 2+ years of Golang architecture experience; • Proficient in Golang frameworks, language features, and data structures, with deep understanding of internals; • Proficient in gRPC / HTTP / WebSocket API development with solid understanding of concurrency and experience with high-concurrency systems; • Familiar with distributed systems; proficient in Kafka, gRPC and other mainstream middleware, with understanding of underlying principles; • Hands-on experience with Claude Code for AI-driven development; • Strong logical thinking and business comprehension skills; good coding habits with clear structure and naming conventions; • Docker and Kubernetes experience preferred. Nice-to-Haves • Experience with multi-channel push platforms (SendGrid / Twilio / Firebase / Telegram Bot); • Salesforce or similar CRM system integration experience; • AI chatbot or LLM application development experience.