Senior Full Stack Engineer

### The Role [Tolken](https://himalayas.app/companies/tolken) is a deeply technical team looking for a builder who craves complexity and ownership. You will work across the stack, from the core ledger to the user interface, ensuring systems are not just functional, but hyper-scalable, secure, and auditable. You will be hands-on in design, implementation, and deployment, collaborating closely with the founders to ship production-grade features in a high-velocity environment. ### Key Responsibilities * Design, build, and maintain end-to-end features across backend (ledger, routing services) and frontend (React-based UI). * Implement and evolve production-grade APIs, data models, and integrations for a high-throughput financial system. * Own the full lifecycle of features: design, implementation, testing, deployment, and ongoing reliability in production. * Collaborate closely with the VP of Engineering, founders, and other engineers to translate product requirements into technical designs and delivery plans. * Improve performance, scalability, and observability of the platform through profiling, tuning, and better monitoring. * Contribute to engineering standards, code reviews, and technical decision-making in a fast-paced startup environment ### Stack & Core Requirements * 5+ years building high-throughput, distributed backend systems; you understand the difference between “working” and “production-grade.” * Strong backend experience in Python (FastAPI preferred), Go, or Java. * Strong command of modern frontend stacks (e.g., React) and ability to build complex, data-dense interfaces. * Deep understanding of modern database design; depth in Postgres and Redis is a strong plus. * Hands-on experience with cloud-native environments (GCP preferred), containers, and Kubernetes. ### System Architecture & Practices * Mastery of distributed systems concepts: microservices, idempotency, retry/backoff strategies, and eventual consistency. * Experience with event-driven architectures and high-volume queues (e.g., Kafka, Redis Streams) and caching layers. * You build with observability in mind: metrics, tracing, and logging, and are comfortable working with modern monitoring stacks. ### Requirements ### **Essential:** * 5+ years of experience as a full stack or backend-heavy engineer working on production systems. * Strong proficiency in at least one of: Python (FastAPI preferred), Go, or Java, including building and operating APIs. * Solid experience with modern frontend frameworks (e.g., React), comfortable building complex, data-dense interfaces. * Strong experience with relational databases and caches; depth in Postgres and Redis is highly valued. * Hands-on experience with cloud-native infrastructure (GCP preferred), Docker, and Kubernetes. * Solid understanding of distributed systems, event-driven architectures, and designing for reliability and scalability. * Comfortable operating in a low-structure, high-ambiguity startup environment with a high degree of ownership. ### **Desirable:** * Web3 & privacy: experience with Ethereum/L2s, smart contracts, and especially zero-knowledge proofs (zkSNARKs) for privacy-preserving audit trails. * AI/ML: experience with graph-based models, fraud detection, or anomaly detection on live transaction streams. * Fintech DNA: background in payments, treasury, or other high-audit, regulated environments. * Prior early-stage startup experience and familiarity with rapid iteration and continuous delivery. ### **Who You Are** * **First-Principles Thinker:** You don't just use tools; you understand _why_ they work. You can reason from the ground up to solve novel problems in hybrid (Fiat/Crypto) finance. * **High Velocity:** You move extremely fast and thrive in high-ambiguity environments. You ship to learn. * **Low Ego, High Output:** You care about the product, not the pedigree. You are comfortable switching contexts rapidly—debugging a race condition one hour and designing a new API the next. * **Owner Mindset:** You don't wait for a ticket. You see a gap, you step in, and you fix it. ### Equal Opportunities Statement [Tolken](https://himalayas.app/companies/tolken) is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. Originally posted on [Himalayas](https://himalayas.app)