Resume

≪Business Domains≫: Financial, Decentralize and centralize exchange, NFT marketplace, ERP ecosystem

≪Technical Domains≫: Backend, (Frontend when needed)

≪Self PR≫: Senior Backend Engineer with more than 7 years of experience building scalable financial and blockchain-related systems using Node.js and TypeScript. Specialized in performance optimization, microservice architecture, and high‑throughput backend services. Proven track record improving system performance (5–10x), reducing infrastructure costs (15 pods to 2 pods), and delivering complex features in production environments. Experienced working directly with product teams to translate business requirements into scalable technical solutions.

・Platform: NodeJs

・Programming language: Typescript, Javascript

・Framework : NestJs, ExpressJs, Moleculer, Vite, VueJs

・Database : PostgreSQL, MySQL, MongoDB, Redis

・Database Lib : TypeORM, Sequelize, Knex, Prisma

・Queue : SQS, BullMQ, Kafka, Gearman, RabbitMQ

・DevOps: Docker, Github & CICD, AWS(EC2, S3, SQS, SES,...), Lens, K8S, PM2

・Blockchain network: BSC, Polygon, Xinfin, Cardano, Aura, and Hedera

・Salary Hero - Senior software engineer - May 2024 - NOW

・FIS - Senior backend blockchain engineer - Sep 2023 -> May 2024.

・VMO - Senior backend blockchain engineer - Sep 2022 -> Sep 2023.

・Sotatek - Senior/Lead backend engineer - Apr 2021 -> Sep 2022.

・GHTK - Fullstack Developer - Sep 2019 -> Apr 2021.

≪Project≫: Salary Hero (Salary Hero company)

≪Business≫: Financial platform providing payroll management, earned wage access, and employee financial services for enterprise clients.

・Worked across 20+ microservices including account-api, auth-api, company-service, ewa-api, ewa-summary-service, education-api, notification-api, notification-service, and voucher-service.

・Collaborated directly with product teams to gather requirements, break down features, estimate timelines, and deliver scalable solutions.

・Designed and implemented backend services supporting multi-tenant financial workflows.

・Designed and implemented PDPA compliance system supporting customizable policies per company, including consent tracking, audit storage, and reporting.

・Built flexible benefit management system allowing companies to configure spending categories, budgets, and employee rules.

・Identified and optimized slow SQL queries, improving performance by 5–10x across critical workflows.

・Resolved long-standing performance issues in voucher service; reduced infrastructure usage from 15 pods to 2 through deep analysis and optimization.

・Improved system reliability and scalability through refactoring and performance tuning initiatives.

Product: https://www.salary-hero.com/

≪Project≫: Horoscope-v2 (FIS Company)

≪Business≫: A crawler that crawl all transactions from multiple network blockchain base cosmos. It's used for check transaction history for quickly response instead of query to blockchain network.

・Refactor slow logic of job for better performance in insert and get data.

・Migrate table transactions, events, blocks,... with over 700M of records for each to use partitioned table, indexing for better performance.

・Jobs for automation create new partition and create check constraint for tables partitioned.

・Refactor project for support run on multiple chains instead of each branch has different logic related on specific chain run on.

・Write unit test for logic working on.

・Migrate and improve performance for more than 10 tables with total over 10B of records from that improve speed of query.

・Make the project support multiple chains base on cosmos.

Product: https://aurascan.io/

≪Project≫: FCX (Sotatek Company)

≪Business≫: A web application related to blockchain with a main feature that supports people can trade and staking their coin tokens.

・Work closely with customer,PM, business analysis and tester to get and clear requirements.

・Research about decentralize exchange concepts, define flow and solution.

・Build base source code, set up development environment.

・Seperate tasks, estimate time line, create plan for each sprint, follow and support to make sure task done on time.

・Build smart contract base on 0x protocol and openzepplin.

・Module authenticate and authorization.

・Module order, transacion and trading.

・Module matching engine to match orders.

・Module PNL that report profit and loss for user.

・Module socket with redis.

・Module process transactions and interact with smart contract.

・Units testing for all logic of system / performance test scripts with K6 for system.

・Deploy, debug, monitor and improve system performance and security.

・Project of the year.

・The first decentralize exchange project of company.

Product: https://www.velo.org

≪Project≫: Dex Screener (Sotatek Company)

≪Business≫: A crawler project that crawl all transactions from ethereum, binance smart chain, polygon, xinfin,.... From transactions crawled will be used to calculate, build history of tokens price, from that show up to user to see.

・Work closely with BA, PM and customer's team lead, together with teamember solve business logics.

・Seperate tasks, estimate time line, create plan for each sprint, follow and support to make sure task done on time.

・Design system for multiple chains, build code base, setup develop environment for team.

・Module crawl transaction events and handle events crawled from multiple chains.

・Module socket with redis.

・Module queue with Redis and BullMq.

・Write unit test for related logics worked on.

・Write test performance scripts to test workload and performance of system.

・Monitor system about error and slow process from that fix and improve performance of system through indexing and partition for table, check query conditions, refactor logic.

・Review pull request and support members complete their tasks.

・Project complete before deadline.

・Good performance of system reach customer required.

・10.000 cc/s with K6 running good on single node 16cpus with success rate 99.99% and server workload < 40%

Product: Customer then cancel for release product cause the down trend of blockchain. But the product run as good as https://dexscreener.com/

≪Project≫: ERP Ecosystem (GHTK Company)

≪Business≫: Internal system used to manage hole process of GHTK company, include checkin, manage customer orders, shop, shiper, salary,....

・Write automation job to calculate salary of more than 20 thousand employees such as cod part time, cod start, sale, b2c, c2c, customer services, cod province,....

・Build tools for reporting, checking and managing employ salary for director, manager, and so on.

・Design and implement checkin service.

・Work closely with teams of mobile, big data, accountants and BA analysis, providing solution for business problem.

・Maintenance system for new fomular change every month.

・Improve performance by monitoring and detect slow query, then decide for caching, refactor, indexing or partition,... if needed.

・Handling over 70% salary of employee need to calculate of company. Update employee salary done on time, never be late.

・Refactor and improve system so that reduce time of calculate salary from 2 days to 15 minutes.

・Good performance for business on tables more than 1 billion of records and 120 million of records inserted per month.

・The first person creating automatic payroll management software instead of manual manipulation from the developer to help reduce workload and speed up progress.

・Certificate of Master Dev, employee of year from company.

Product: Internal using only. https://id.giaohangtietkiem.vn/

≪Project≫: BSC-DEX (Self Product)

≪Business≫: A decentralize exchange ERC20 token on biance smart chain, support create limit order market order, trade your token to another token,...

・Research about new 0x protocol to build Dex smart contract.

・Research about concepts of Dex such as ticker 24h, orderbook, OHLCV....

・Took full responsibility for build back-end, front-end and smart contract from scratch.

・Self product.

・Develop within 30 days. More than 500 clones and 1000 views on github.

・Good performance, less step, lower cost fee, exactly and easy for setup than FCX.

・Can be use for developing more for production or for studying.

Product: https://github.com/matthew-nguyen-20032023/BSC-DEX

≪Project≫: RLF (VMO Company)

≪Business≫: Manage sale house and marketplace for NFT and Token on Hedera chain.

・Exploring, working with team to decide the technical solution.

・Gathering, analysing client requirements.

・Took full responsibility for back-end.

・Build code base for project that updates the latest version of all techstacks.

・Implement module authenticate and authorization.

・Implement module Listing House for managing, buying and selling house.

・Implement module of market place to trade assets.

・Implement module of Blockchain integration: buy, sell, auction NFTs,..

・Develop and deploy smart contract.

・Initialize project, code and review code.

・Good feedback from customer, PM and technical leader of project.

・Solve problem blockchain team can not and join as main coder of blockchain.

・Project done before deadline with less people.

≪Project≫: NOC (VMO Company)

≪Business≫: Markeplace NFT and Token on Cardano chain.

・Discuss with temleader for improve coding style, refactor code base and define workflow interact with blockchain.

・Module authenticate with google and apple.

・Module interact with blockchain for create wallet, get balance, transfer token,...

・Module market place, main logic business.

・BE jobs for market place process with blockchain.

・Make the whole process working between backend team and blockchain team smothly that previous project is not.

・Transfer working experiance with blockchain for team.

・Good feedback from customer, PM, and backend team leader of project.

Product: Dvold application already on IOS and Android store, by searching for "Dvold" keyword

≪Project≫: VIN NFT (Sotatek Company)

≪Business≫: NFT management on Polygon chain

・Work closely with VIN's solution architecture to clear requirements and decide flow, techstacks,....

・Design, build code base, setup develop environment and implement flow crawl and handle Vin's NFT data on Polygon chain.

・Module authentication.

・Module manage transfer NFT history.

・Module mint NFT.

・Automation job for update NFT, job for save NFT from unexpected ipfs expiration.

・APIs for related NFT logic such as, detail NFT, list NFT, claim NFT,....

・Build UI for user.

・Handle all backend logic from scratch.

・Troubleshooting unexpected ipfs expiration for VIN.

・Project complete before deadline.

・Good feedback and satisfied from VIN's customer.

Product: https://vinfirst.vinfastauto.eu/en

≪Project≫: KPI (GHTK Company)

≪Business≫: The project separate manage employee salary services from ERP system below, so that using new technology for good performance and also for not depend on ERP system when deploy or change.

・Migrate KPI logic of Ecom system from PHP to Nodejs and data from Mysql to MongoDB.

・Build base code, setup development environment.

・Intergate authentication services and build authorization module.

・Migrate queue jobs from Gearman to Kafka.

・Migrate data from Ecom system to KPI system.

・Intergate unit test for all logic of calculate salary.

・Deploy system, support tester and BA for check.

・Seperate KPI system from ERP, so that not depend on server, deployment,... of ERP any more.

・Use new technology like kafka, nodejs, mongoDB so that bring good performance, good support.

・Unit test to ensure correct logic.

Product: Internal using only. https://id.giaohangtietkiem.vn/

≪Project≫: Thanh Dat Computer (Private company)

≪Business≫: Shoping website of computer, camera and printer.

・Design UI, clear requirements.

・Took full responsible to build the website using nodejs and wordpress.

・Deploy and maintance product using hostinger.

・Migrate product to wordpress for good SEO.

・The first project running on production.

・Experience about domain, setup, deploy and maintance website through hostinger.

Product: http://thanhdatcomputer.vn/