Jacob Heijligers

Principal Software Consultant

I architect, build, and scale backend, mobile, and web systems end-to-end.

Remote · Globally flexible · U.S. timezone friendly

backend

Rust

Go

Java

Python

SQL

frontend

TypeScript

React

Next.js

infra

Kubernetes

Terraform

AWS

GCP

specialties

Architecture

Networks

Reverse Engineering

jobs@heijligers.me

I'm a freelance software consultant with a master's in Computer Science & Engineering from TU Delft and over 10 years of experience bringing complex ideas to life, fast.

I thrive on full ownership and enjoy building products end to end, from architecture to launch. I'm passionate about creative problem solving and love finding elegant solutions to hard or unconventional challenges. Whether it's reverse engineering a closed protocol, scaling backend systems, or shipping experimental side projects, I like to push the boundaries of what's possible.

I'm highly self-directed but also comfortable collaborating within teams, especially when clarity, speed, and high standards matter. I communicate clearly, move quickly, and take pride in delivering high-quality, high-complexity systems with minimal overhead.

Outside of client work, I build tools and prototypes to explore new ideas or improve my own life. I'm currently available for high-impact work. Remote-first, but happy to meet in person when it makes sense.

Highlights

10+ years experience across backend, frontend, mobile, infra
Built and launched 10+ production-grade systems solo
Fast learner who tackles deep technical challenges with high-quality output
2nd place in TON blockchain smart contract competition (2024)

Experiences

Full Stack Engineer

Worked across the stack on backend services, features, and Kubernetes infrastructure. Hardened the platform by fixing widespread security issues, built an antispam system, broadcast bot, and rebuilt the public-facing website.

Miljoenhuizen.nl

Rebuilt a real estate platform from the ground up. Created a Rust-based ingestion pipeline, backend, and modern TypeScript frontend. Optimized PostgreSQL queries for fast page loads while maintaining a lean, maintainable codebase.

Custom chatbot for Kik, built with async Python on top of reverse-engineered APIs. Grew into a full-featured, AI-enhanced group admin bot used by millions. Designed a distributed, Kubernetes-backed system resilient to platform changes and adversarial behavior.

Backend Architect

Architected and implemented the backend for a smart sleep robot startup on AWS. Integrated IoT data ingestion, analytics, authentication, and OTA firmware updates as the sole backend engineer.

Full Stack Engineer

Built and maintain backend (Java), web frontend (TypeScript), and mobile apps (React Native) for a Dutch flight ticket aggregator. Fully responsible for feature development, scaling, and platform stability.

Projects

TON Trustless Bridge Challenge

Smart Contract Developer

Placed shared 2nd in a global competition hosted by Telegram. Built a trustless cross-chain bridge entirely within smart contracts using TL-B and Tact, with little to no prior blockchain experience.

Smart Contracts

Reverse engineered Google Maps' internal API to build a faster, cleaner frontend in Next.js, hosted on Cloudflare's edge. Demonstrated deep understanding of undocumented systems and UI performance.

Reverse Engineering

Developed a web-based tool that clones Android APKs so they can be used alongside each other.

Reverse Engineering

MiBand Heart Rate Monitor

Reverse engineered Bluetooth connectivity with the MiBand fitness tracker to create a real-time heart rate display website.

Reverse Engineering

Built a Dutch-language web app that helps users choose the right smartphone through a step-by-step questionnaire. Focused on guiding non-technical users toward informed purchase decisions.