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Brian.

Full-stack Software Engineer

Brian Joseph Keyrupan

Web apps across Web3, DeFi, NFT, and marketplaces — React/Next.js, NestJS, Python, PostgreSQL, Solidity, and AWS.

Professional experienceGitHubLinkedIn

About

I'm a full-stack engineer with 3+ years shipping production dashboards, smart contracts, data pipelines, risk monitoring agents, and multi-chain integrations. I care about clear product surfaces, reliable ops, and code that teams can extend.

Focus
Web Developments, Dapps, Smart Contracts, Web3, DeFi, NFTs, marketplaces
Currently Based in
Jakarta, Indonesia
Open to relocate or remote roles globally
Contact
bkeyrupan@gmail.com·+6281586688888·WhatsApp

Skills

Tools and stacks I use regularly across the stack.

Languages

  • TypeScript
  • JavaScript
  • Python
  • Solidity
  • SQL

Frontend

  • React
  • Next.js
  • TanStack Router
  • TanStack Query
  • Tailwind CSS
  • React Native
  • Vue.js

Backend & data

  • NestJS
  • PostgreSQL
  • Drizzle ORM
  • Alembic
  • Dagster
  • REST
  • GraphQL
  • Supabase
  • OAuth

Web3

  • Solidity
  • Foundry
  • Viem
  • Wagmi
  • JSON-RPC
  • ERC-721
  • ERC-1155
  • ERC-165

Infra

  • AWS SQS
  • AWS KMS
  • Redis
  • Lambda
  • Docker
  • Slack bots
  • Swagger

Experience

Roles and initiatives where I owned features end to end.

  1. Software Engineer

    Mon Co. (formerly LiquidX) — Mon Protocol Team

    LinkedInWebsite

    Mar 2024 – Present

    Yield Monitoring Service

    • Designed and implemented a Dagster pipeline (assets, jobs, schedules, asset checks, sensors) for market snapshots and risk/metrics computation, stored in PostgreSQL with Alembic migrations for schema evolution.
    • Integrated multiple DeFi protocols (Morpho, Aave, Athena, Hyperliquid) via JSON-RPC / Web3, GraphQL, and typed protocol clients; modeled shared abstractions for ingestion and configuration.
    • Built downstream analytics with pandas, numpy, and quantstats (e.g. rolling returns, volatility, Sharpe ratio, Sortino ratio, liquidity, and utilization metrics). Added operational reliability: configurable Slack run-failure sensors on critical jobs.

    Havenfi

    app.havenfi.co/dashboard

    • Shipped a React dashboard with TanStack Router (file-based routes) and TanStack Query for cached server state, charts (Recharts), and Tailwind 4 + shadcn/Radix UI aligned to a design system.
    • Implemented wallet connectivity and chain-aware reads with wagmi, viem, and Reown AppKit.
    • Developed and maintained REST endpoints in NestJS for domains including vaults, markets, token prices, users, auth, admin, audit, and reallocation-related flows; used Swagger for API documentation.
    • Python repo deploying Hypernative risk agents for HavenFi: APY monitoring, oracle vs reference price checks, and Morpho-related on-chain reads.

    Collect Fun

    Live appInstagram

    • Shipped a gacha-style mystery pack experience where pulls are backed by real PSA-graded Pokémon inventory; BrainCloud powers the game backend, with Next.js for the web app and NestJS for payments and integrations.
    • Built in-app claim and intake flows so collectors who win physical slabs can submit shipping details and the team can verify outcomes before fulfilling graded cards.
    • Impact: connected on-chain collectibles and marketplace flows to accountable physical stock—end to end from pack opening through digital inventory to shipped PSA slabs with less manual back-and-forth.

    Holodeck

    • Internal dashboard app that connects Binance, Bybit, Gate, MEXC (API keys) and Ethereum-family addresses (read-only), then shows unified totals, 24h volume, daily change, holdings, allocation charts (Recharts), and recent transactions.
    • Infrastructure: AI Agent Slack bot for automated pull request generation, streamlining content workflows.

    Shiny RWA Platform

    sequence.xyz/blog/sequence-powers-collectshiny-pokemon-marketplace

    • Designed the NFT redemption and marketplace infrastructure for PSA-graded Pokémon cards.
    • Built robust backend systems using NestJS and TypeScript for admin panel functionality.
    • Developed smart contracts (ERC721AC, ERC1155, ERC165) for NFT management and access control.

    Mon Protocol Launchpool

    app.pixelmon.ai/launchpool

    • Developed the frontend in Next.js and TypeScript for the token distribution platform.
    • Developed and deployed smart contracts across 10+ mainnets (Ethereum, Base, Blast, Arbitrum, BNB, Optimism).
    • Impact: facilitated partnerships with 30+ projects, distributing $6M+ worth of tokens to users.
    • Built a comprehensive admin panel for business operations and reward management.

    Pixelmon E3 Evolution

    www.pixelmon.ai/wiki/zoology

    • Developed audited Solidity for Evolution 3: collectors burn Serum 3 (ERC-1155) to evolve Evolution 2 Pixelmon into Evolution 3 on-chain, with rules and flows aligned to the product spec.
    • Built the Evolution 3 frontend so owners can complete the on-chain evolution with clear wallet flows, ERC-1155 Serum 3 and Evolution 2 requirements, and transaction feedback.
    • Impact: 438 Evolution 2 Pixelmon NFTs evolved through the launch.

    MON ID

    • Built the production Next.js MON ID storefront so players can buy in-game currency for Wardens Ascent and Pixelmon TCG — game discovery, shop inventory, and on-chain checkout — with Thirdweb (ecosystem wallet, SIWE-backed auth, account abstraction with gas sponsorship), typed clients to MON ID, Auth Sphere, and payments APIs, TanStack Query and Jotai, Zod-validated environment config and Mon UI.
    • Shipped multi-chain configuration (e.g. Avalanche and Base for token and sale contracts), top-up flows, transaction history with filtering, and responsive layouts for store and checkout.
    • Implemented the TypeScript/NestJS payments API for EIP-712–signed purchase intents across multiple EVM chains — Drizzle/PostgreSQL for intents, webhooks, price pegs, and append-only state transitions; Redis; AWS SQS and KMS-backed signing with viem for receipt and log validation against sale contracts.
    • Exposed versioned REST with Swagger, JWT and API key auth, HMAC-verified indexer webhooks (Alchemy and custom indexers).

    Mon Protocol Questing

    • Revamped Questing UI and shipped smart contract integration for 15M $MON token distribution.

    GVRN

    LinkedInWebsite

    • Built a responsive frontend dashboard in Next.js focused on layout, navigation, and access patterns for the broader GVRN product.

  2. Software Engineer Intern

    F-Secure Malaysia

    WebsiteLinkedIn

    Aug 2022 – Nov 2022

    • Migrated R&D backends to Docker and built automated testing with Python and Robot Framework.

Professional experience

Products and platforms I've helped ship.

Hackathons

ETHGlobal builds and bounties

  • PredPump

    ETHGlobal Thailand — Nov 2024

    Open prediction market — 4th Scroll, Push bounty, Blockscout prize.

    Showcase

  • ReversiFi

    ETHGlobal Singapore — Aug 2024

    Non-custodial crypto payment SDK.

    Showcase

  • FiatX

    ETHGlobal Sydney — May 2024

    P2P fiat ramp with World ID and Chainlink VRF.

    Showcase

  • Footy Stars

    ETHGlobal Istanbul — Nov 2023

    Provable football sim with ZKPs and EZKL — finalist, 2nd SportFi, Best on Scroll.

    Showcase

Personal projects

Solo experiments on Solana and the browser — shipping small tools and trading-adjacent UX outside of hackathon weekends.

  • Solana meme coin blind box

    Web app

    Users buy random coins from configurable boxes (e.g. graduated tokens above a market cap). Jito bundler batches swap transactions from the Jupiter API; NestJS backend.

    • Solana
    • Jupiter
    • Jito
    • NestJS

  • Solana token swap extension

    Chrome extension

    Detects token addresses in tweets, surfaces price data, and enables swaps via Jupiter APIs.

    • Chrome extension
    • Jupiter API
    • TypeScript

Education

Bachelor of Software Engineering

Asia Pacific University of Technology and Innovation (APU), Malaysia

Nov 2020 – Nov 2023

CGPA 3.5