Niels Andriesse, Developer in London, United Kingdom
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Niels Andriesse

Verified Expert  in Engineering

Software Developer

London, United Kingdom
Toptal Member Since
April 5, 2016

Niels has a strong focus on entrepreneurial ventures and a natural aptitude for software engineering. He taught himself programming during his aerospace engineering studies, where he used his skills to develop powerful structural analysis and orbit design tools. Niels has since been a major part of multiple world-class startups, building and shipping high-end consumer-facing iOS and Android applications using languages such as Swift, Kotlin, JavaScript, Rust, and Python.


Android, Kotlin, Java, iOS, Objective-C, Swift, Rust
Kotlin, Java, Android, iOS, Objective-C, Swift




Preferred Environment

MacOS, Python, Android, iOS, Git, PyCharm, Android Studio, Xcode, Visual Studio Code (VS Code)

The most amazing...

...project I've worked on is an orbit design tool capable of finding the optimal trajectory between two arbitrary celestial bodies.

Work Experience

Lead iOS Engineer | Lead Android Engineer | Project Lead

2019 - 2021
  • Developed a fully decentralized, onion-routed, and end-to-end encrypted private messenger for iOS and Android, contributing heavily to both platforms.
  • Scaled the application from zero to over 150,000 active users, achieving outstanding user reviews on both iOS and Android in the process.
  • Ensured the security and privacy of the application, as later verified by an independent audit performed by QuarksLab.
  • Led a team of engineers to ensure the rapid and efficient development of a high-quality product.
  • Built part of the application's back end using Rust.
  • Set development priorities, ensured a consistent product vision across platforms, and recruited new developers.
Technologies: Android, Kotlin, Java, iOS, Objective-C, Swift, Rust

Lead Android Engineer | Senior iOS Engineer

2017 - 2019
  • Built large parts of both the iOS and the Android applications from the ground up, including frameworks for database management, client-server communication, and the UI infrastructure.
  • Ensured a consistent and high-quality product experience across platforms and managed development priorities.
  • Led and collaborated with an international team of engineers to rapidly develop and deploy a complex fintech application.
Technologies: Kotlin, Java, Android, iOS, Objective-C, Swift

Senior iOS Engineer

2016 - 2017
DynamiCare Health
  • Used sophisticated geofencing methods to ensure appointment attendance.
  • Ensured HIPAA-compliant handling of sensitive patient data throughout the application.
  • Created frameworks for the integration of third-party Bluetooth devices.
  • Rapidly developed a high-quality iOS front end following design guidelines.
Technologies: iOS, Swift

Senior Full-stack Engineer

2016 - 2016
  • Rapidly developed a high-quality iOS front end featuring many custom UI elements.
  • Built a scalable, secure back end that conformed to RESTful design practices.
  • Ensured secure handling of user data throughout the entire stack.
  • Managed the deployment of the application to AWS servers.
Technologies: Amazon Web Services (AWS), MongoDB, iOS, Node.js, Swift

Senior Full-stack Engineer

2016 - 2016
  • Built a scalable, performant, and secure back end capable of handling large amounts of video.
  • Ensured conformance of the API to RESTful design practices.
  • Designed and developed an iOS front end featuring highly custom UI, efficient video handling, location tracking, and secure transmission of user data.
  • Managed an AWS server for the processing of large amounts of data.
Technologies: Amazon Web Services (AWS), MongoDB, iOS, Node.js, Swift


2013 - 2016
  • Designed and developed Archimedes, a graphing calculator for iOS and Android.
  • Developed a custom mathematics engine with fully automatic unit handling and support for symbolic mathematics.
  • Implemented an advanced formula library featuring large amounts of data, with the ability to search formulas by name, mathematical symbols, topics, and more.
  • Scaled the application from zero to 250,000+ active users.
Technologies: Android, Java, iOS, Objective-C, Swift

Senior Android Engineer

2014 - 2015
  • Built online identity assurance software for the GOV.UK Verify program.
  • Ensured the secure transmission of highly sensitive personal data.
  • Transformed a large, poorly structured, partially insecure codebase into a structured, secure one.
Technologies: Android, Java

Archimedes is a graphing calculator for iOS and Android that features a powerful symbolic mathematics engine, fully automatic unit handling, a unique in-built formula library, and advanced animations.

GOV.UK Verify

Digidentity is one of the certified companies in the GOV.UK Verify program. Their software makes online identity assurance straightforward.

Structural Analysis Tool

I developed a structural analysis tool for the preliminary sizing of an arbitrary wing. The work involved combining complex aerospace engineering with software development.

Orbit Design Tool

I developed an orbit design tool that automates the complex process of finding the optimal trajectory between two arbitrary celestial bodies.

An experiment involving the use of an evolutionary algorithm for the optimization of a neural network’s hyperparameters, as well as the idea of having a group of neural networks work together to achieve better results than the group’s members could achieve individually.

Session Core
I developed a Swift framework for Loki Service Node network-based messaging. Loki Service Nodes are servers in the Loki Project's decentralized network. The framework has full support for onion routing, as well as advanced handling of unreliable Service Nodes.

A framework for representing and performing numerical operations on mathematical functions in Swift. The framework allows the user to numerically approximate derivatives, integrals, roots and extremums of arbitrary functions.

Speaker at Coder Factory Career Day

I gave a talk about best practices and what it's like to be a programmer.
2013 - 2014

Erasmus Minor in Entrepreneurship

KTH Royal Institute of Technology - Stockholm, Sweden

2011 - 2014

Bachelor's Degree in Aerospace Engineering

Delft University of Technology - Delft, The Netherlands


Protobuf, Socket.IO, GridFS, Retrofit 2, CocoaPods, GNU Multiple Precision (GMP), Node.js


Adobe Photoshop, Adobe Illustrator, MATLAB, LaTeX, Mongoose, Git, PyCharm, Atom, Android Studio, Xcode


Express.js, Cocoa, Cocoa Touch


SQL, C++, Objective-C, JavaScript, Python, Java, Swift, Rust, Kotlin


Scrum, Mobile Development


iOS, MacOS, Android, Amazon Web Services (AWS), Amazon EC2, Azure, Visual Studio Code (VS Code)


Realm, MongoDB, ObjectBox DB


Cryptography, Decentralization, Software Development, Machine Learning, Crypto

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