Example web application with clojure for a repl-driven development demonstration. And some capabilities of clojure applications in terms of web micro-services:

• Writing an always up-to-date swagger definition yaml with swagger1st

paths:
  /users:
    get:
      summary: get users
      description: |
        get all user ids
      tags:
        - users
        - awesome
      # Hint: here we reference the actual Clojure function to call when this request comes in
      operationId: foo.handlers/get-all-users

• Writing SQL queries with (surprise) SQL syntax - hugsql

-- :name get-all-user-ids :? :*
-- :doc Get all user ids we have
SELECT id FROM users

• Migrating the database with ragtime

ALTER TABLE users ADD COLUMN age INTEGER DEFAULT NULL

• Wiring the dependencies of the application and managing the state - mount

(mount/start)

• Getting the synergie of all those things together using REPL and the text editor of your choice

• Brain
• Laptop
• Java 8 (sudo apt-get install openjdk-8-jre)
• Leiningen installed - (wget https://raw.githubusercontent.com/technomancy/leiningen/stable/bin/lein -O $HOME/bin && chmod u+x ~/bin/lein)
• Local postgresql user: postgres, password: postgres with a database foo freshly created and available
• Being able to run this repository without huge stacktraces with lein run or at least lein repl
• Preferably - your favorite text editor and the way to connect to a REPL from it (can assist with emacs/spacemacs setup for now, approach me beforehand if you have any questions about cursive/vim/lighttable)
• Alternatively (for ubuntu 16.04 and later) - emacs-2.4.4+ + spacemacs:

sudo apt-get install emacs24
#![ATTENTION] - erasing the old emacs config - please back up existing one 
git clone https://github.com/syl20bnr/spacemacs ~/.emacs.d
git clone https://github.com/dixel/foo
cd foo
lein
emacs -nw src/foo/core.clj
<ALT>+<X> cider-jack-in <ENTER>

• Starting it locally
• Adding functionality to all the sides (migrating the database, adding new API endpoints, modifying internal logic)
• Building an artifact, deploying to playground cluster

lein run

or

lein repl

;starting without the database
(mount/start-without #'foo.storage/database)
;or if postgres database is in place - starting everything
(mount/start)
; ... checking things
(mount/stop)

Navigate to the UI to get the Swagger UI for discovery.