Crypto Exchange KYC and Persistence

Financial backend systems with KYC/AML, exchange integrations, blockchain nodes, and polyglot persistence.

Why the work mattered

A financial platform needed onboarding, KYC/AML, exchange integration, and multiple data models for account and network workflows. The exchange needed secure onboarding, fast data models, identity verification, and integrations with liquidity and blockchain infrastructure.

What could not break

Financial compliance, sensitive user documents, correctness, performance, and multiple persistence models.

How the pieces fit

NestJS microservices with PostgreSQL, MongoDB, Neo4j, Redis, Elasticsearch, Binance integration, and blockchain nodes.

My part

Built KYC/AML verification, document validation, sanction screening, exchange integration, and network/accounting algorithms.

What I was responsible for

• NestJS microservice implementation
• KYC/AML and document validation workflows
• Exchange integration and persistence across PostgreSQL, MongoDB, Neo4j, Redis, and Elasticsearch

Calls I made

• Used different stores for relational, document, graph, cache, and search needs instead of forcing one database model.
• Kept compliance-sensitive flows explicit and auditable rather than hiding them in generic handlers.

What I watched in production

• Sensitive document handling
• Correctness of financial/accounting flows
• Integration reliability with exchange and blockchain infrastructure

What changed

Enabled compliant onboarding and scalable backend features for financial workflows.