Rust Developer - Senior Backend Engineer / Founding Engineer

Senior Backend Engineer / Founding Engineer - Rust / Fintech / Web3

We are looking for a Senior Backend Engineer to own and build the core Rust service that handles all money movement for a fast-growing onchain finance company. This is, by design, the only system in the company that can lose money - which is why it's written in Rust, reviewed the most strictly, and shipped the most carefully.

The service is the engine behind every flow that touches a ledger, a payment rail, a hold, a mint or burn, an on-chain action, or the reserve. It integrates a core banking platform on one side and the blockchain on the other, and has to keep both perfectly reconciled to a standard that a banking regulator could trace line by line.

This is a hard build: native mint and redeem at the deposit layer, 24/7/365 settlement across banking rails (ACH, wire, SWIFT, and similar) and on-chain rails, an audit-grade double-entry reserve ledger, and dual-control compliance workflows. If you want to work on systems where correctness is non-negotiable and the domain is genuinely interesting, this is that role.

What You Will Build

The service is a single Rust application organized into clean domain modules, following a hexagonal (ports and adapters) architecture. Areas you will work across:

• Banking domain. Account lifecycle, internal book transfers, beneficiaries, deposit and withdrawal orchestration across rails, velocity and exposure limits.
• Stablecoin domain. Mint, redeem, and withdraw state machines wired into reserve accounting and on-chain settlement.
• Reserve ledger. The audit-grade double-entry journal. Every mint, burn, withdraw, and fee posts here in the same database transaction as the order state change - the load-bearing aggregate a regulator would trace.
• Relayer. The subsystem that signs and submits transactions to chains, manages gas and nonces, handles retries and reorgs, and tracks confirmations, with leader election and an executor pool.
• Sanctions and compliance gates. Synchronous sanctions screening, Travel Rule handling, and address freeze flows bound to the stablecoin contract through a signing registry.
• Provider adapters. Clean trait boundaries to a core banking platform, payment-rail connectors, custody and signing providers, and compliance vendors.
• Three-way reconciliation. Continuous reconciliation between the reserve ledger, on-chain supply, and customer balances, with drift detection and attestation support.

Tech Stack

• Language: Rust (Tokio async runtime, axum web framework)
• Persistence: PostgreSQL via sqlx; Redis for idempotency, rate limiting, and distributed locks
• Blockchain: alloy for type-safe EVM interaction, contract calls, and signers
• Patterns: Hexagonal architecture, outbox pattern for reliable event publication, idempotency keys on every state-mutating endpoint, RFC 7807 problem details for errors
• APIs: REST with OpenAPI generated from routes via utoipa
• Observability: OpenTelemetry tracing, Prometheus metrics, structured JSON logs, immutable audit log
• Quality gates: cargo fmt, cargo clippy (deny warnings), cargo deny, unit and integration tests against ephemeral Postgres and fake provider doubles, signed container images

How We Build: AI-First, Automation-First

This is an AI-native engineering team building a bank-like system that runs 24/7/365 with a deliberately small headcount. Leverage is the whole strategy.

• AI-first development. Engineers drive coding agents (Claude Code and similar) as a core part of daily work: generating and reviewing Rust, writing tests and migrations, and navigating the codebase. Real fluency is expected. AI output is held to the same bar as any pull request, and on the money path, human judgment owns the final call.
• Automation-first operations. Reconciliation, drift detection, alerting, runbooks, and incident response are code, not human checklists. The reserve ledger and three-way reconciliation are built to self-check and page a person only on a genuine exception.
• Built for agents and humans alike. Clean OpenAPI, structured logs, and machine-readable audit trails are first-class, so both people and automated systems can drive and audit the core safely.
• Eliminate toil on sight. If a task is manual and repeatable, it's treated as a bug.

Required Skills

• 5+ years building production backend systems (Rust preferred; other static languages considered)
• A track record with correctness-critical systems: payments, ledgers, trading infrastructure, exchanges, settlement, or anything where a bug costs money or data integrity
• Comfort with distributed-systems failure modes: retries, at-least-once delivery, reconciliation, idempotency, leader election, and the difference between a read you can retry and a write you cannot
• The judgment to write boring, auditable, well-tested code where it's needed, and to know which parts of the system demand it
• AI-native by default - daily use of coding agents, with a sharp, earned sense of when to trust them and when not to, especially around code that moves money
• An automation reflex: instinctively turning manual operational work into code, monitoring, and self-healing systems
• Strong written communication

Nice to Have

• Experience with on-chain transaction submission at scale: relayers, gas management, nonce handling, reorg recovery, or MEV-aware broadcasting
• Exposure to banking or payments rails: ACH, wire, SWIFT, FedNow, RTP, or core banking platform integration
• Familiarity with stablecoin mechanics: mint and burn flows, reserve management, attestations, or token contract administration
• Experience operating under a compliance or audit regime (SOC 2, bank examination, sanctions screening, KYC/KYB)
• Smart-contract literacy (Solidity / EVM) sufficient to reason about the contract surface the service drives

Perks:

20 days of vacation to enjoy from the moment you generate them + 3 days off per year where we don't work and take the opportunity to recharge

Udemy courses and other platforms, where you have access to all courses and content assigned to you as a talent development plan. You can also propose new courses to add to the course catalog

DEC Institute certification “ CHARTERED BLOCKCHAIN ANALYST” with a 50% discount

English classes at different levels

Flexibility: we know that people have a personal life to attend to. As long as you organize yourself and fulfill your working hours, everything is okay

A day off and a gift (sweet or savory) for birthdays and other special dates

Team trips to promote team-building, discover new places, and participate in tech events

Remote work: we are a remote-first company, although we have a nice office space in Montevideo, we prioritize remote work. We also offer the option of coworking when teams want to gather in other countries

Long retention plan, career opportunities, and there may be other bonuses.