Now in SingaporeOpen to interesting work

Jeffrey Marvin Forones

Senior Software Engineer · Singapore

I build scalable backends, thoughtful frontends, and the developer tools I wish I had.

View my workContact me
Jeffrey Marvin Forones
Years building software
10+
Of users served at imToken
Millions
Published OSS packages
5+
Products I run today
2

About

A bit about me

I'm a software engineer based in Singapore who has spent the last ten years building things people rely on. My work spans the whole stack: scalable REST APIs and microservices on Node.js, frontends in React and Angular, mobile apps, and cloud-native infrastructure on AWS.

Along the way I've protected blockchain and token-based assets for millions of users at imToken, driven digital-transformation projects and mentored junior engineers at Viseo, championed engineering best practices and DevOps automation at Fullspeed Technologies, and cut my teeth building APIs and data layers at CodeRepubliq.

Outside of client work I build and maintain my own products and open-source libraries — AssertKit for testing email flows, ColorSnaps for extracting color palettes from images, and a handful of Python and JavaScript packages that other developers depend on. I also write on Medium about systems design, React, and the lessons I pick up along the way.

What I bring

  • Full-stack delivery across backend, frontend, and mobile.
  • Scalable, secure systems at the scale of millions of users.
  • Cloud-native architecture on AWS with solid CI/CD and DevOps.
  • Mentorship and a habit of raising the team's engineering bar.

Experience

Where I've worked

Roughly a decade of building, shipping, and supporting production software — listed most recent first.

  1. Senior Software Engineer

    Recent

    imToken

    Managed and safeguarded a wide range of blockchain and token-based assets on a wallet trusted by millions of users worldwide.

    • Built and maintained features handling sensitive crypto and token assets at global scale.
    • Focused on security, reliability, and correctness for high-stakes financial flows.
    • Collaborated across a distributed team to ship and support production wallet software.
    Node.jsTypeScriptReactBlockchainSecurity

  2. Senior Software Engineer

    Several years

    Viseo

    Delivered backend, frontend, and mobile work on digital-transformation initiatives within a microservices architecture, and mentored junior engineers.

    • Designed and built REST APIs with Node.js and ReactJS in a microservices architecture.
    • Worked with serverless and managed cloud services including AWS Lambda and AWS Aurora.
    • Contributed across web and mobile applications for enterprise clients.
    • Mentored junior developers and helped raise the team's engineering standards.
    Node.jsReactJSAWS LambdaAWS AuroraMicroservicesMobile

  3. Senior Software Engineer

    Earlier

    Fullspeed Technologies

    Drove engineering best practices, machine-learning applications, and DevOps automation while helping the team move quickly without breaking things.

    • Championed engineering best practices and helped resolve technical impediments for the team.
    • Worked on machine-learning applications alongside core product engineering.
    • Automated delivery with CircleCI, including blue-green deployments for safe releases.
    DevOpsCircleCIMachine LearningCI/CDNode.js

  4. Backend & MongoDB Software Engineer

    Early career

    CodeRepubliq

    Built APIs and data layers with Node.js and MongoDB, with frontend work in AngularJS and hands-on DevOps and AWS integration.

    • Developed robust REST APIs on Node.js backed by MongoDB.
    • Built frontend features with AngularJS.
    • Handled DevOps tasks and AWS integration for deployments.
    Node.jsMongoDBAngularJSAWSDevOps

Skills

Tools I reach for

The languages, frameworks, and practices I use to ship reliable software.

Languages

JavaScriptTypeScriptPythonJava

Frontend

ReactNext.jsAngularJSTailwind CSSMobile

Backend

Node.jsREST APIsMicroservicesFlaskDjango REST

Data

MongoDBAWS AuroraMongoEngineSQL

Cloud & DevOps

AWSAWS LambdaCircleCICI/CDBlue-green deploys

Ways of working

Test-Driven DevelopmentMentoringSystem DesignCode Review

Projects

Things I've built

Products and open-source work I design, build, and maintain myself.

AssertKit

End-to-end email testing for your test suite.

A developer platform for testing email-driven flows without the flake. Wait for emails, extract OTPs, follow magic links and verification URLs, and manage inboxes and custom domains — straight from your tests. Ships official SDKs for Node, Playwright, and Cypress, plus a CLI.

ProductDeveloper ToolsTestingNode.jsPlaywrightCypress
assertkit.com

ColorSnaps

Extract beautiful color palettes from images.

A web app that pulls clean, usable color palettes out of any image — built for designers and developers who want a fast way to capture the colors they love and put them to work.

ProductTypeScriptDesign ToolsWeb
colorsnaps.art

Open-source packages

Libraries I've published to npm and PyPI that other developers build on.

npm@assertkit/nodeOfficial Node SDK for AssertKit — wait for emails, extract OTPs, run flows, manage inboxes and custom domains.npm@assertkit/playwrightPlaywright fixture for AssertKit — test signup, OTP, magic-link, and verification-URL email flows without flake.npm@assertkit/cypressCypress commands for AssertKit — wait for OTP / magic-link / verification-URL email flows.npm@assertkit/cliCommand-line interface for AssertKit — watch inboxes, run flows, and manage custom domains from the terminal.PyPIflask-starter-kitFlask application boilerplate for building microservices.PyPIflask-blueprintBlueprint generator for Flask applications.PyPImongoengine-utilsHuman-readable JSON serialization, de-serialization, and pagination for MongoEngine.PyPIdatastore-mapperObject mapper for Google Datastore without requiring App Engine.

Writing

I write things down

Notes on systems design, React, and the lessons I pick up — published on Medium.

Understanding Systems Design Requirements

Breaking down how to read and reason about the requirements behind a system design problem.

Read on Medium

Function Bindings in Your React Component

A practical look at the ways you can bind functions in React components and when to use each.

Read on Medium

What I've Learned from "Surrounded by Idiots"

Notes and takeaways from Thomas Erikson's book on communication styles and working with people.

Read on Medium

Contact

Let's build something

I'm always happy to talk about interesting engineering problems, product ideas, or collaboration. Drop me a message below and it'll land straight in my inbox.

or email me directly
LinkedInGitHubMediumnpmPyPI