The MBTA Customer Technology department is working on new projects like fare collection systems and real-time transportation updates to improve the rider experience. They chose to use the Elixir programming language and Phoenix framework for new development because Elixir is functional, fast, concurrent, fault-tolerant, and has a large community backing it. Elixir's features like pattern matching make it well-suited for tasks like filtering alerts by date, route, and stop.

1. Old Company -
New Technology
Using Elixir at the MBTA

2. MBTA Customer Technology
“Improving Rider Experience through Technology”

3. MBTA Customer Technology
● Fare Collection System
(AFC 2.0)

4. MBTA Customer Technology
● mbta.com
● API V3
● T-Alerts

5. MBTA Customer Technology
● Countdown signs
● Digital displays
● e-ink

6. MBTA Customer Technology
● Green Line
Dispatch

7. MBTA Customer Technology
“Startup” within a large government agency

8. Choosing Development
Platform
● Looked at:
single-page app on React, Ruby, Python,
Node, Java

9. Choosing Development
Platform
● Our choice: elixir and Phoenix

10. ● Functional

11. ● Functional
● Fast

12. ● Functional
● Fast
● Concurrent

13. ● Functional
● Fast
● Concurrent
● Fault-tolerant

14. ● Large development community
● Time-tested platform
● Mnesia database
● Phoenix channels

15. ● Pipelines

16. Alerts.all
|> filter_by_date(Timex.today)
|> filter_by_route("Red")
|> filter_by_stop("Porter Square")

17. ● Pattern matching

18. def full_name(:subway, name), do: "#{name} Line"
def full_name(:bus, name), do: "Route #{name}"
"Red Line" = full_name(:subway, “Red”)
"Route 5" = full_name(:bus, 5)
full_name(:rocketship, “Orion”) (raises exception)

19. ● Hiring

20. THE END