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# Senior Back-End Developer (Payments)

- **Company:** Toyota-lift of Minnesota Inc.
- **Location:** United States (Remote available)
- **Experience:** Expert
- **Salary:** $70,000.0 - $90,000.0
- **Contract:** Permanent contract
- **Skills:** Java (Programming Language), .NET Framework, Application Programming Interfaces (APIs), Artificial Intelligence, Amazon Web Services, Amazon S3, C Sharp (Programming Language), Continuous Integration, Command-Query Responsibility Segregation (Software Development), Software Design Patterns, Digital Assets, Distributed Systems, Amazon DynamoDB, Payment Systems, Identity and Access Management, Message Broker, NoSQL, Object-Oriented Software Development, Performance Tuning, RabbitMQ, Blockchain, Azure DevOps Pipelines, SignalR, SQL Databases, WebSocket, Multithreading, Concurrency, State Machines, AI Coding Agents, Backend, Git, Kotlin, Build Management, Integration Tests, Kubernetes, Information Technology, Apache Kafka, Webhooks, OpenSearch, Golang, Microservices
- **Published:** November 5, 2026
- **Apply:** https://arc.dev/remote-jobs/j/redirect/pwttr559iy

## About the Role

* Bachelor's degree in Computer Science, Engineering or a related technical field
 * 5+ years building back-end systems in a strongly typed language (e.g. C#/.NET, Java, Kotlin, Go)
 * Strong grasp of OOP, design patterns, distributed systems, concurrency, multithreading and performance optimisation
 * Experience with SQL and NoSQL databases, CI/CD, Git and testing frameworks
 * Strong problem-solving, attention to detail and ownership in a fast-paced environment
 * Daily, hands-on use of AI coding agents on production work (not just autocomplete), with the judgement to give them the right context and to review and own what they produce
 * Fluent written and spoken English

Nice to have

 * Strong C#/.NET experience
 * Familiarity with payment rails (SEPA, SWIFT, Faster Payments, on-chain and Lightning) and blockchain transactions, wallets and stablecoin transfers
 * Experience with orchestration patterns: sagas, outbox, compensation across several external providers, message brokers (e.g. Kafka, RabbitMQ)
 * Knowledge of double-entry ledgers and payment reconciliation, and hands-on experience with custody APIs
 * Experience with AWS (EKS, DynamoDB, Cognito, IAM) and Kubernetes in production
 * Autonomy and ownership: you take loose problems to production in small, reviewable PRs, follow your code after release, write clearly, and work directly with Operations, Compliance and Finance
 * Curiosity for finance, digital assets and the regulatory side of what we build
 * Italian is a plus

## Description

We're looking for a Senior Back-End Developer to join our Payments squad, which owns Hercle's money journeys end to end. The goal: one unified way to move money from A to B (deposits, withdrawals, transfers, transfer-outs and rebalancing), whoever is sending and whoever holds the funds., * Design and build a scalable, event-driven payment orchestration engine for deposits, withdrawals, transfers and rebalancing

 * Implement state machines, idempotency, retries and compensation so every money movement is safe, traceable and recoverable
 * Integrate orchestration with account data, provider adapters (banks, custodians, exchanges) and the core ledger
 * Build and operate the job fleet that automates rebalancing and recurring flows, with strong monitoring and alerting
 * Work with product, Operations and banking infrastructure clients to remove manual steps and improve journey success rate and speed
 * Write clean, documented code, review peers' work, fix bottlenecks and bugs, and improve CI/CD

How We Build

Every squad works on our two C# code bases: the Execution API, the client-facing gateway exposing documented REST and real-time WebSocket (SignalR) APIs, and the Back Office API, used daily by Operations, Compliance and the trading desk. Behind them sits a fleet of domain microservices and provider integrations.

 * .NET 10 microservices over gRPC; event-driven internals with CQRS, domain events and background jobs
 * AWS throughout: EKS, DynamoDB (in-memory caches on the hot path), Cognito, OpenSearch, S3
 * Azure DevOps CI/CD, with integration tests run against real deployed environments
 * AI-first engineering: agents write and refactor code, review every PR and help investigate incidents

What You Will Work On

You own every money movement on the platform, from the client request to the provider confirmation and the ledger entry.

 * Deposit, withdrawal and transfer flows over WebSocket and REST, incl. payees and crypto addresses
 * Banking orchestration: one canonical model routing to banks, crypto custodians and Lightning
 * The balance pipeline: reservations, a ledger entry per change, compensation on provider failure
 * Async provider states (webhooks, retries, idempotency): no payment lost or executed twice
 * Operations flows: approvals, rebalancing across exchanges and accounts, scheduled jobs