Toptal
Talent Network: Senior Backend Engineer (Node.js)
TLDR
Build and scale the backend for a borderless neobank, integrating traditional banking and blockchain technologies while ensuring reliability and correctness in financial operations.
Job Summary:
In this position, you will build and scale the backend for a borderless neobank on stablecoin rails. You’ll work across traditional banking integrations, blockchain infrastructure, and card issuance - ensuring every transaction is correct, every webhook is idempotent, and every workflow survives a crash. We are an agentic-first engineering team: you’ll ship with AI-assisted tooling daily, not as an experiment.
This is a remote position. We do not offer visa sponsorship or assistance. Resumes and communication must be submitted in English.
Responsibilities:
The following information is intended to describe the general nature and level of work being performed. It is not intended to be an exhaustive list of all duties, responsibilities, or required skills.
What You’ll Own
End-to-end feature delivery across banking, cards, crypto, and compliance modules
Temporal workflow design for critical financial operations
Webhook integration reliability (inbox pattern, signature verification, IP whitelisting)
Event-driven architecture evolution
Observability and incident response for payment flows
Our Way of Work
Agentic-first: AI tools are infrastructure, not novelty. You’ll use Claude Code with custom skills, automated reviews, and MCP integrations daily
Correctness over speed: This is a financial system — idempotency, transactional integrity, and crash-resilience are table stakes
Codified standards: Architecture decisions live in .claude/rules/, ADRs, and per-module CLAUDE.md files — not tribal knowledge
TDD encouraged: Red-Green-Refactor with dedicated tooling support
Pre-commit quality gates: Lint + typecheck on commit, full test suite on push
Qualifications and Job Requirements:
Core Backend
Strong TypeScript/Node.js (NestJS preferred)
PostgreSQL — schema design, transactions, advisory locks, performance tuning
GraphQL API design (Apollo Server, resolvers, custom scalars, pagination)
Event-driven architecture — outbox/inbox patterns, idempotency, at-least-once delivery
Distributed Systems & Reliability
Temporal.io or equivalent durable workflow engine (Cadence, Step Functions)
Designing idempotent activities and deterministic workflows
Retry policies, non-retryable error classification, and failure handling
Transaction boundaries in distributed systems
Fintech Domain
Payment rails familiarity (ACH, SWIFT, Fedwire) or willingness to learn quickly
Double-entry accounting concepts
Webhook signature verification (HMAC, ECDSA, Svix)
KYC/KYB compliance flows
Web3 / Blockchain
Solana ecosystem (SPL tokens, transaction construction, RPC interaction)
Stablecoin mechanics (USDC, EURC, mint/transfer/burn)
Wallet custody models (MPC wallets via Privy or similar)
Cryptographic signing (KMS-backed ECDSA)
Agentic Engineering
Proficiency using AI coding assistants (Claude Code, Cursor, Copilot) as a daily multiplier
Ability to write effective prompts, review AI-generated code critically, and maintain code quality
Comfort with AI-assisted workflows: automated PR reviews, test generation, codebase exploration
Understanding when to trust AI output and when to verify manually
Observability & Operations
APM and tracing (Datadog or equivalent)
Error tracking (Sentry)
Structured logging (Pino/Winston)
Blue-green deployments, health checks, graceful shutdown
Nice to Have
Experience with Privy, Sumsub, Noah, or Rain APIs specifically
AWS KMS / HSM-backed signing
PostgreSQL logical replication
NestJS module architecture at scale (20+ modules)
Contributing to internal developer tooling (custom slash commands, MCP servers, Claude Code hooks)
Toptal is a global network connecting companies with top freelancers in business, design, and technology, allowing for scalable, on-demand team augmentation. With an extensive pool of talent and a fully remote model, Toptal stands out by blending top-tier professional expertise with a supportive virtual environment that prioritizes innovation and collaboration.
- Founded
- Founded 2010
- Employees
- 500+ employees
- Industry
- Internet Software & Services
Senior Back-end Software Engineer