Senior Full Stack Engineer

The role

You will design, build, and maintain end-to-end features across the backend and frontend. You will work on a high-throughput financial system from core ledger to user interface.

What you will do

• Design, build, and maintain end-to-end features across backend and frontend.
• Implement and evolve production-grade APIs, data models, and integrations.
• Own the full lifecycle of features including design, implementation, testing, and deployment.
• Collaborate with the VP of Engineering, founders, and other engineers.
• Improve performance, scalability, and observability of the platform.
• Contribute to engineering standards, code reviews, and technical decision-making.

Required qualifications

• 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).
• Strong experience with relational databases and caches.
• 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.

Nice to have

• Web3 & privacy: experience with Ethereum/L2s, smart contracts, and especially zero-knowledge proofs (zkSNARKs).
• 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.
• Depth in Postgres and Redis is a strong plus.
• GCP preferred

About the company

Tolken is a deeply technical team looking for a builder who craves complexity and ownership.