I've been approached by a business consultant for programming a website + web application for his client, which is a logistics company. The web application will have a tracking system for tracking their GPS enabled fleet (400 tricks).
Kindly advise me which scaleable stack can I use for the back-end. I'm planning to use React for the front-end.
And by back-end, I also include the database. I'm considering PostgreSQL as the database system.
Spring is a good decision for your needs, but you should build correct microservice architecture for good scaling. Work with database can be easy with ORM (e.g. Hibernate) and migrations (e.g. Liquibase) If you need the best performance and scaling on frontend, you can use Angular or React.