Senior Back-End Developer (Foundations & Reporting)

As a Senior Back-End Developer at Hercle, you join the Foundations & Reporting squad, which owns the core ledger, balances, reconciliation, reporting, and the adapters connecting Hercle to banks, custodians, venues and other providers. You solve complex problems at the intersection of global finance and digital assets for institutional clients worldwide, in a lean, flat team where ideas matter more than titles.

What you'll do

• Design, build and maintain the double-entry ledger and balance services that are Hercle's source of truth
• Scale the reconciliation engine that automatically matches Hercle's books against banks, custodians and venues
• Build resilient adapters to banking, custody, exchange and stablecoin providers, including webhooks and deposit processing
• Own the Reporting API and data feeds used by Finance, Data, auditors and regulators
• Drive platform reliability: uptime, monitoring, logging, tracing and alerting across services
• Write clean, documented code, review peers' work, fix bottlenecks and bugs, and improve CI/CD

What you bring

• A Bachelor's degree in Computer Science, Engineering or a related technical field
• 5+ years building back-end systems in a strongly typed language such as C#/.NET, Java, Kotlin or 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
• Knowledge of ledgers, accounting, reconciliation or financial reporting systems, and financial controls and audit requirements in a regulated environment
• Experience integrating custody, exchange or banking APIs and their webhooks
• Familiarity with observability and SRE practice (OpenTelemetry, Prometheus, Grafana, ELK or similar) on Kubernetes
• Experience with NoSQL data modelling (keys, secondary indexes, consistency) at production scale, ideally DynamoDB
• 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 Hercle builds. Italian is a plus

What we offer

• Competitive base salary of EUR 70,000-90,000, depending on experience
• Real ownership: in a squad with a clear problem space, you own what you ship from first idea to production
• Career growth and flexible remote/hybrid working in a collaborative, forward-thinking team

About Hercle

Hercle is a fintech building institutional-grade infrastructure that bridges fiat, stablecoins and digital assets, enabling cross-border payments and banking infrastructure for global trade. Serving 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.