Senior Back-End Developer

h3About The Company /h3 pHercle is a fast-growing fintech building institutional-grade infrastructure that bridges fiat, stablecoins, and digital assets, enabling cross-border payments and banking infrastructure for global trade. /p h3About The Company /h3 pHercle is a fast-growing fintech building institutional-grade infrastructure that bridges fiat, stablecoins, and digital assets, enabling cross-border payments and banking infrastructure for global trade. /p pServing over 200 clients globally, Hercle provides banks, brokers, payment service providers, fintechs, commodity traders, corporate treasuries, and other NBFIs with seamless solutions for cross-border payments and treasury management. /p h3Working at Hercle /h3 pWe're a lean, flat team where ideas matter more than titles and everyone gets real responsibility from day one. You'll solve complex problems at the intersection of global finance and digital assets, for some of the world's largest institutions and corporates. If you're curious, driven and excited to shape how money moves globally, we'd love to meet you. /p h3About The Role /h3 pWe're looking for a Senior Back-End Developer to join our Foundations Reporting squad, which owns Hercle's technical foundations and information flow: the core ledger, balances, reconciliation and reporting, and the adapters that connect us to banks, custodians, venues and other providers. /p h3Key Responsibilities /h3 ul liDesign, build and maintain the double-entry ledger and balance services that are Hercle's source of truth /li liScale the reconciliation engine that automatically matches our books against banks, custodians and venues /li liBuild resilient adapters to banking, custody, exchange and stablecoin providers, including webhooks and deposit processing /li liOwn the Reporting API and data feeds used by Finance, Data, auditors and regulators /li liDrive platform reliability: uptime, monitoring, logging, tracing and alerting across services /li liWrite clean, documented code, review peers' work, fix bottlenecks and bugs, and improve CI/CD /li /ul h3How We Build /h3 pEvery 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. /p ul li.
NET 10 microservices over gRPC; event-driven internals with CQRS, domain events and background jobs /li liAWS throughout: EKS, DynamoDB (in-memory caches on the hot path), Cognito, OpenSearch, S3 /li liAzure DevOps CI/CD, with integration tests run against real deployed environments /li liAI-first engineering: agents write and refactor code, review every PR and help investigate incidents /li /ul h3What You Will Work On /h3 pYou own the source of truth: what Hercle holds, where it holds it, and the systems that keep the two in agreement. /p ul liCore ledger, balances and transactions services that every trade and payment writes to /li liAdapters to banks, custodians, exchanges, stablecoin issuers and payment platforms /li liIdempotent webhook ingestion and deposit processing, resilient to provider outages /li liThe reconciliation engine and position management system (PMS) /li liReporting API and data feeds, plus platform reliability on Kubernetes /li /ul h3Requirements /h3 ul liBachelor's degree in Computer Science, Engineering or a related technical field /li li5+ years building back-end systems in a strongly typed language (e.g. C#/.
NET, Java, Kotlin, Go) /li liStrong grasp of OOP, design patterns, distributed systems, concurrency, multithreading and performance optimisation /li liExperience with SQL and NoSQL databases, CI/CD, Git and testing frameworks /li liStrong problem-solving, attention to detail and ownership in a fast-paced environment /li liDaily, 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 /li liFluent written and spoken English /li /ul h3Nice to have /h3 ul liStrong C#/.
NET experience /li liKnowledge of Ledgers, accounting, reconciliation or financial reporting systems, and financial controls and audit requirements in a regulated environment /li liExperience with integrating custody, exchange or banking APIs and their webhooks /li liFamiliarity with observability and SRE practice (OpenTelemetry, Prometheus, Grafana, ELK or similar) on Kubernetes /li liExperience with NoSQL data modelling (keys, secondary indexes, consistency) at production scale, ideally DynamoDB /li liExperience with AWS (EKS, DynamoDB, Cognito, IAM) and Kubernetes in production /li liAutonomy 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 /li liCuriosity for finance, digital assets