Mustkeem K
๐Ÿ†

Top 1% Engineer Worldwide

Verified by Upstack ยท out of 50,000+ applicants

Mustkeem K

Senior Full-Stack Engineer ยท 8+ Years

Building production-grade systems at scale โ€” from VeVe's real-time drops serving 500K+ concurrent users to Paytm's payment platform at 350M+ users. Full-stack across React, Next.js, Node.js, NestJS, and AWS. Domain expertise in Web3, Crypto Payments, Finance, and Marketplaces.

500K+
Concurrent Users
VeVe real-time drops
8+
Years Experience
Full-stack, production systems
350M+
Platform Users
Paytm payment flows
8,000+
Stack Overflow Rep
Top community contributor

Experience

VeVe / ECOMI

Aug 2021 โ€“ Present

Remote ยท New Zealand

Full Stack Engineer

Global digital collectibles marketplace โ€” Marvel, Disney, DC, Star Wars โ€” millions of users worldwide.

  • Architected real-time drop system handling 500K+ concurrent users โ€” WebSocket, Kafka event streaming, queue management, zero-downtime releases.
  • Owned full-stack delivery end-to-end: MySQL schema โ†’ NestJS/GraphQL APIs โ†’ React/Next.js frontend. SSR pipeline improved organic traffic 40%, initial load <2s.
  • Scaled engineering quality: code coverage 35% โ†’ 85%, 1000+ code reviews conducted, MTTD reduced 60% via DataDog monitoring across microservices.
  • Led RFC reviews and architecture discussions with senior leadership; defined microservices boundaries, API contracts, and event-driven messaging patterns. Mentored 3 junior engineers.

Cognizant ยท Verizon

Jul 2020 โ€“ Jul 2021

Remote ยท Hyderabad

Full Stack Developer

Enterprise digital transformation for Verizon (Fortune 500) โ€” pricing automation and quote management at scale.

  • Built React/TypeScript/Redux frontend for CPP-MS โ†’ CPP-VP migration: quote generation, automated approval workflows, and business logic failure handling.
  • Developed Custom Pricing Portal reducing manual pricing cycles and improving enterprise quote turnaround. Led frontend deliveries and code reviews.

Paytm

Jun 2019 โ€“ Jun 2020

Noida, India

Full Stack Developer

India's largest digital payment ecosystem โ€” 350M+ registered users, high-throughput checkout flows.

  • Checkout conversion +15% via streamlined UX and reduced API latency. Frontend bundle size -25%, page load time -1.2s through code splitting and lazy loading.
  • A/B testing framework shipped with feature flags โ€” drove 12% retention improvement on checkout pages. Daily active transactions +10% from product feature delivery.

Sparx IT Solutions

Dec 2016 โ€“ May 2019

Noida, India

Frontend โ†’ Full Stack

Agency delivering product builds for CarDekho, Storybook.ai, and multiple enterprise clients.

  • CarDekho auto marketplace: vehicle listing pages, search/filter, dealer dashboards โ€” React, Node.js, MySQL. Promoted to Full Stack within first year.
  • Legacy jQuery โ†’ React migration across client projects improved page load performance 50% and developer velocity.

Shipcent

Jan 2019 โ€“ Jan 2020

India ยท Part-time

Founder & Engineer

Founded a B2B freight marketplace connecting businesses with truck vendors on AWS โ€” React, Node.js, Express, MySQL.

  • Built vendor onboarding, rating, and comparison system; engineered payment and reconciliation engine handling invoicing, COD tracking, and remittance matching.
  • Led product strategy, technical architecture, and customer relationships while managing a team of 2 developers.

Technical Skills

Frontend
React.jsNext.jsReact NativeTypeScriptJavaScript ES6+ReduxReact QueryApollo ClientTailwind CSSWebpackVite
Backend
Node.jsNestJSExpress.jsGraphQLREST APIsWebSocketMicroservicesEvent-Driven DesignTypeORMMongoose
Databases
MySQLMongoDBPostgreSQLRedisElasticSearchDynamoDB
Cloud & DevOps
AWS (EC2, ECS, S3, CloudFront, RDS, SQS, Lambda)DockerTerraformNGINXGitHub ActionsCI/CD
Messaging
Apache KafkaRabbitMQAWS SQS
Auth & Security
JWTOAuth 2.0FusionAuthSSORBACKYC/AML Integration
Testing
JestPlaywrightCypressReact Testing LibraryEnzyme

Writing & Tutorials

In-depth technical series on the stack I use every day.

NestJS

Nest.js Tutorial

A comprehensive series of 187 in-depth articles covering controllers, routing, TypeORM, Prisma, GraphQL, microservices, AWS deployments, and beyond.

187Articles
FreeTo read
Start Reading
Git

Git Tutorial

A hands-on series of 11 in-depth articles covering remotes, branching, rebasing, cherry-pick, reflog, Git hooks, and keeping a clean history.

11Articles
FreeTo read
Start Reading
JS

JS Design Patterns

A focused series of 5 in-depth articles covering Singleton, Module, Factory, Facade, Decorator, and Observer patterns in TypeScript.

5Articles
FreeTo read
Start Reading
โœ“

JS Testing

A thorough series of 18 in-depth articles covering unit testing with Jest, Enzyme, React Testing Library, Cypress, Playwright, and mocking strategies.

18Articles
FreeTo read
Start Reading
TS

Node.js TypeScript

A deep-dive series of 15 in-depth articles covering streams, buffers, the event loop, HTTP/2, child processes, worker threads, and more.

15Articles
FreeTo read
Start Reading
.*

Regex Course

A concise series of 4 in-depth articles covering basic concepts, elegant patterns, ES6 grouping features, and avoiding catastrophic backtracking with lookahead.

4Articles
FreeTo read
Start Reading
Ex

TypeScript Express

A practical series of 15 in-depth articles covering routing, MongoDB, TypeORM, Postgres, JWT auth, testing, CI/CD, and Mongoose patterns.

15Articles
FreeTo read
Start Reading
W4

Webpack 4 Course

A concise series of 8 in-depth articles covering entry/output, loaders, plugins, code splitting, tree shaking, and dynamic imports.

8Articles
FreeTo read
Start Reading

Content sourced from wanago.io