Element • London, United Kingdom

Senior Android Developer- Cryptography - Element (UK/EU remote)

Employment type:  Full time


Fully flexible hours

Dog friendly

Job Description

Who We Are

Element is the startup which employs the core team behind matrix.org— the leading project for secure, open decentralised communication.

Matrix’s mission is to make messaging as open as email— allowing everyone to choose where their data is hosted, enjoy private conversations thanks to advanced encryption, and ultimately be in control of their own communication.

The Matrix protocol is used by millions of people globally, from the French and German governments through to community groups and open source projects like Mozilla, KDE, GNOME and Wikimedia.

Matrix powers Element, our flagship messaging apps for the web, iOS & Android, along with EMS, our SaaS platform for personal & professional use.

We build things for everyone, and we know we can’t succeed without a diverse team. Our hiring process is designed to be humane and give candidates the best chance to show us what you can do. If we ever fall down on this, please let us know.

The Role

You'll spend most of your time working on Element Android our flagship Android client, you can take a look at the code on github. Element Android is written in Kotlin and is backed by Realm. This team will mainly focus on improving the global reliability of cryptography in Matrix as well as improving the overall user experience.

Example recent projects:-

  • Implement support for Element Spaces.
  • Improving message timeline responsiveness.

We are open to remote applications, though the core of the Android team is based in Rennes, France and so would prefer a European (or nearby) timezone.

Since (almost) everything we do is open source you can get a great feel for exactly what it would be like to work on Element, why not join our developer channel at #element-android:matrix.org to provide a window into the core team and the community. Come and say hi!


About you

The most important thing is that you believe passionately in the mission of decentralisation of the internet. More specifically that you believe that communications should not be centralised in the hands of a small number of very large organisations and instead individuals should control their own data and choose who they share it with.

Additionally we are looking for someone who is:

  • smart, curious and enthusiastic
  • passionate about building software people love
  • a tireless advocate of code quality (understanding the need for trade-offs in the short term whilst keeping us honest in the long term)
  • empathetic, with both their colleagues and the end user

Your experience

We don’t have hard requirements for the role, we just want to build the best possible team, but we'd be particularly excited to speak to you if you have experience with some of the following:

  • Designing and building performant, maintainable Android applications
  • Familiarity with iOS and web development - First will start everything on Android, but will need to understand codes from other platforms to be able to carry over and fix on all platforms
  • We share a lot of code using Rust, so knowledge of this language is a big bonus.
  • Must be willing to learn Rust with the team if you don’t already know it.
  • Know the basics of cryptography preferably with a background in end to end encryption
  • using Kotlin in professional capacity
  • designing UI using Android ConstraintLayout
  • using libraries like MvRx, Epoxy, ViewModel
  • employing established UX conventions with an eye for aesthetic design
  • working with or as part of an open source community
  • providing and receiving peer code review
  • working in an Agile/Lean development environment


Our general approach is to treat people like adults and acknowledge that by being flexible we create an environment for people to do their best work. For more details here is our manifesto. That said specific points that differentiate us.

  • Work (almost) full time on FOSS projects with high visibility and a large enthusiastic community
  • Since our technology is relevant to anything that requires real-time comms, the role provides exposure to a wide range of domains from web and app dev through to VR, VoIP and IoT.
  • Family friendly environment, many of the team have small children and we look to accommodate that as best we can.
  • People tend to stay with the company for a long time, we take this a sign that we have a cohesive supportive culture, that we have engaging challenging work and that people can develop their skills and careers here for the long term.

Element does not discriminate on the basis of race, sex, colour, religion, age, national origin, marital status, disability, veteran status, genetic information, sexual orientation, gender identity or any other reason prohibited by law in provision of employment opportunities and benefits.

Company benefits

Open to part-time employees
Open to job sharing
Work from anywhere scheme
Enhanced sick pay
Pregnancy loss leave

The FlexScore® is the result of a rigorous 2-step verification of a company’s flexibility

First we assess the flexibility options Element provides and then we anonymously survey a statistically significant proportion of their employees to make sure Element is as flexible as they say they are. Our assessment is based on the six key elements of flexibility: location, hours, autonomy, benefits, role modelling and work-life balance.

We ask the hard questions so you don’t have to.

Working at Element

Company employees


Gender diversity (male:female:non-binary)


Office locations

London, UK and Rennes, France

Funding levels


Hiring Countries

United Kingdom
Awards & Achievements
Most flexible Saas & Dev Software companies

Most flexible Saas & Dev Software companies

Industry awards 2022