Senior iOS Developer – London at What3Words
London, GB

What3words helps everyone talk about everywhere by giving every location on Earth a simple 3 word address. We are looking for an experienced and talented senior developer, who specialises in iOS development and is comfortable working in a fast paced, innovative environment.

You’ll be joining our fast growing app development team, working on our global customer facing technology and researching new ways for users to interact with and understand our addressing system.


Essential Skills:

– Obj-C and Swift

– Good knowledge of Apple Human Interface Guidelines

– Extensive end-to-end experience developing mobile apps, from interpreting UX designs to working with product teams on recursive feedback and testing


– Familiar with AGILE development cycles and JIRA


Desirable Skills:

– Experience with OCR and voice recognition

– Python

– Cloud deployments (AWS)

– C++

– Using RESTful web APIs

– Android / Java Development

– An interest in compression algorithms and/or information theory

– JavaScript


You will have:

– Excellent communication skills in both spoken and written English

– The ability to talk to techies and non-techies in suitable language

– A passion for development and staying current with technology trends

– The ability to work both independently and with others

– A focus on high quality software engineering work and attention to detail

– The ability to work in a fast-paced, deadline-driven environment


Extra credit if you:

– Like maps and location based services and know what a GIS is (we love maps)

– Are able to understand the business context of what you’re doing – understand the value your work creates.

– Enjoy learning new skills in scripting languages and how to use those to showcase our products


About our Tech

For web development, we have chosen ReactJS as our main framework for interactive components, to allow reusability. As well as our main map site and corporate site, we have a wealth of challenging plugins and side-projects (for high-profile customers), using a playground of different technologies.

To be as fast and portable as possible, our core algorithm is written in C++, and works entirely offline. Our algorithm compresses our global database to just 30MB (for all 26 languages) so that it’s fast & portable enough to run on any device, anywhere – this is important for our vision of what3words becoming a ubiquitous worldwide standard. This native code is incorporated into our offline Android & iOS SDKs, and also powers our online HTTP API. For building software, we use CI (Jenkins / Travis) and Docker. Our backends systems (such as our web API and Accounts API) make use of Java and Python to create a robust, low latency API for our users.

We take infrastructure seriously, with a modern cloud-based scripted DevOps approach in AWS, using Python, CloudFormation, Ansible, Packer and S3 for artifacts. We have a fully horizontally-scalable architecture, with automated failover and monitoring. However, we also like to keep things simple where possible.

We have a custom analytics platform built on S3/Athena, and Google Big Query, which our Growth team uses to analyse patterns of user behaviour, and to optimise our content delivery (with A/B testing).

About us

The what3words team is a mix of experienced entrepreneurs, people who have worked at the highest levels in large global organisations, academics, and bright graduates – it’s a good balance, and it’s important for us that we get the right person who is happy working alongside people from these backgrounds.

We have a relaxed and focused office in West London, with regular team socials. We have a culture that encourages curiosity and imagination in how we achieve our goals, and an absolute focus on building a global business.