Skip to content
Workshop
← All work
Personal safety, map appMarch 2024–2026Lead Fullstack React Native Engineer

A night-walking app that suggests the safest route, not the fastest

SafestWay shows the safest route, not the fastest one. To do that it works through millions of records on crime, street lighting and cameras. I designed the whole system.

SafestWay · official job title: Lead Fullstack React Native Engineer

The situation

SafestWay is a personal safety app for walking at night. It does not pick the shortest route. It picks the safest one.

What made it hard?

Millions of records on crime, street lighting and CCTV had to be processed so the app could choose a route from them. I also had to design how the whole system fits together.

What was I responsible for?

  • As Lead Fullstack React Native Engineer I designed the whole infrastructure: the shared codebase (Turborepo), the mobile app (React Native, with a native Kotlin part), the back end (NestJS) and the database (PostgreSQL with PostGIS).
  • The map interface is built on Mapbox GL, and the route finding runs on Graphhopper.
  • The system runs on AWS (ECR, ECS, Fargate).

When this matters to you

  • If you have a lot of map data to process and want one developer who designs everything from the mobile app to the database, this is the work to look at.
  • If you are building a new product, I can help you decide what it should do first, as well as build it.

Links