Backend engineer at a cross-border payments company. Spent the last year building login systems, compliance flows, and the AWS services behind them, improving security and automation across the product. Previously shipped Solidity smart contracts and an NFT marketplace. Builds secure authentication and notification systems on AWS, designs compliance workflows, and develops blockchain infrastructure with multi-chain support.

Koushik Kumar Bug

Backend engineer at a cross-border payments company. Spent the last year building login systems, compliance flows, and the AWS services behind them, improving security and automation across the product. Previously shipped Solidity smart contracts and an NFT marketplace. Builds secure authentication and notification systems on AWS, designs compliance workflows, and develops blockchain infrastructure with multi-chain support.

Available to hire

Backend engineer at a cross-border payments company. Spent the last year building login systems, compliance flows, and the AWS services behind them, improving security and automation across the product.

Previously shipped Solidity smart contracts and an NFT marketplace. Builds secure authentication and notification systems on AWS, designs compliance workflows, and develops blockchain infrastructure with multi-chain support.

See more

Language

Work Experience

Software Engineer at TransF i
August 1, 2025 - Present
Built a shared login and signup service used across multiple TransFi products (BizPay, Checkout, Ramp, Displ-AI), with signed/encrypted requests and least-privilege access per product. Implemented a pre-commit 50-test security suite to prevent cross-product injection. Built BizPay authentication on AWS Cognito (email/password, Google sign-in, TOTP MFA, passkeys) and packaged it as an internal npm library for reuse by other payment backends. Set up magic-link email verification and built notifications using AWS Lambda and SQS. Automated BSA legal agreement workflow by generating form files from customer data, stamping signatures, and notifying the review team on Slack immediately when signed documents land, eliminating manual checks. Built UK compliance (DOFP) and KYB checks gating merchant creation/invites until customer clearance. Developed much of the backend: transaction limits, send money, contacts, multi-approver payments, new currencies, i18n, MongoDB migration, and wired GA4 for
Open-Source Contributor (GSoC '25 application phase) at Google Chrome
February 1, 2025 - April 1, 2025
Moved Web Audio tests from an older audit.js harness to W3C test harnesses (testharness.js), including review of features and bug fixes by the Chromium team.
Full-Stack Blockchain Engineer at Vox Un? (listed as: Voshu/Voy)
September 1, 2024 - July 1, 2025
Built core smart contract infrastructure for a decentralized NFT marketplace on Ethereum. Developed a custom ERC-721 collection, implemented an EIP-712 typed structured data signing scheme to support off-chain signature generation, and gasless lazy minting for single and bulk NFT items. Implemented secure purchasing, transfer, and redemption mechanisms. Expanded to multi-chain support by deploying contracts on Polygon to reduce gas costs and increase throughput. Led cross-functional engineering to integrate, test, and wire smart contract APIs across frontend interface and backend services.
Intern at Prep Inst(a)echnology
January 1, 2024 - March 1, 2024
Built PrepChat, a real-time chat feature over WebSockets with token-based authentication for connections.

Education

B.E. in Computer Science & Engineering at Birla Institute of Technology, Mesra
June 1, 2022 - November 1, 2024

Qualifications

Add your qualifications or awards here.

Industry Experience

Financial Services, Software & Internet, Computers & Electronics, Professional Services, Gaming