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$
USD
I will build your web3 wallet or crypto payment backend in typescript
nestjs, jsredis, postgres, rabbitmq, microservices, python, golang
Highly versatile software engineer with over 20 years of experience, transitioning from early career expertise in online game development (PC, browser, mobile) focusing on server-side engineering (net...
About this Gig
Crypto money flows punish sloppy backend work. I have built these systems in production.
Relevant work:
- A custodial wallet backend covering registration, deposits, withdrawals and internal transfers (NestJS, Prisma, PostgreSQL, RabbitMQ).
- A Web3 payment system integrating banks and virtual credit cards - I owned deposits, withdrawals and fund consolidation.
- An x402 HTTP payment gateway: on-chain payments bound to HTTP requests, with multi-wallet support and a CDP Facilitator.
- On-chain data infrastructure in Go - an EVM DEX price processor on Kafka to ClickHouse, a Substreams real-time pipeline, and a BSC indexer.
What you get:
- Correct accounting: idempotent writes, unique references, no double-credits on retries
- Chain confirmation handling, reorg awareness and a reconciliation job
- Clean separation between ledger and chain adapter, so adding a chain stays cheap
- Tests, including the failure paths everyone skips
I will be straight with you: I am a backend engineer, not a smart-contract auditor. If your problem is contract security, hire an auditor. If your problem is that money moves and the books do not reconcile, that is exactly what I do.
Purpose:
DeFi
Programming language:
TypeScript
Keep your assets and information safe
Cryptocurrency services focus solely on developing and programming. Never share sensitive information or private keys with others.
FAQ
Do you write smart contracts too?
I integrate with them and can write straightforward ones, but I am not an auditor. For contract security, hire a dedicated auditor.
Can you add a new chain later?
Yes - that is why the chain adapter is separated from the ledger. Adding one is usually days, not a rewrite.
Who holds the private keys?
Whatever you choose. I support self-managed, KMS or a third-party signer, and I will tell you the trade-offs.
