ios & backend challenges update (#3)

.github/workflows/ci.yml

@@ -11,8 +11,8 @@ on:
       - "**.md"
 
 env:
-  GO_VERSION: "1.21.3" # https://go.dev/dl/
-  GOLANGCI_LINT_VERSION: "v1.55.1" # https://github.com/golangci/golangci-lint/releases
+  GO_VERSION: "1.21.4" # https://go.dev/dl/
+  GOLANGCI_LINT_VERSION: "v1.55.2" # https://github.com/golangci/golangci-lint/releases
 
 jobs:
   lint:
@@ -29,6 +29,14 @@ jobs:
           skip-cache: true
           working-directory: ./ios/server
 
+  security:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: golang/govulncheck-action@v1
+        with:
+          go-version-input: ${{ env.GO_VERSION }}
+          work-dir: ./ios/server
+
   build:
     runs-on: ubuntu-latest
     steps:

backend/readme.md

@@ -0,0 +1,62 @@
+# Backend Challenge
+
+This challenge is part of the backend hiring process at [Heart
+Hands](https://hearthands.tech/).
+
+## Why this challenge?
+
+Heart Hands is operating with a small team of dedicated & talented people. We
+are looking for seasoned engineers with a deep technical knowledge, strong
+understanding of their technical stack, and excellent product intuitions to join
+our team.
+
+This exercise has been designed to give a glimpse of what it is like to build a
+messaging app, and the kind of technical challenges we face and care about. We
+are expecting you to spend between 4 and 6 hours on this challenge.
+
+## Instructions
+
+You are tasked with the server-side implementation of a messaging app that
+allows clients to send and receive text messages in private 1:1 chats.
+
+We enforce no technical constraints: you are free to choose the language, data
+layer, network protocol, and design your API as you see fit. You are
+purposefully being given a lot of freedom here, and you will not be judged on
+these decisions alone, but we will challenge the understanding of the trade-offs
+you make.
+
+Functional requirements:
+
+- [ ] Clients should be able to uniquely identify themselves with a phone number
+      (without authentication)
+- [ ] Clients should be able to send messages to other clients via their phone
+      numbers
+- [ ] Clients should be able to list their chats
+- [ ] Clients should be able to list all messages in a chat
+
+## Bonus
+
+Some topics that we find interesting to dig:
+
+- [ ] Choose a network protocol that enables soft real-time message delivery to the clients
+- [ ] Make the server message ingestion idempotent
+- [ ] Add support for sent/delivered/read message status
+- [ ] Add support for chats and messages pagination
+- [ ] Implement SMS phone number verification to authenticate the clients
+- [ ] Support SMS forwarding to relay the messages to the clients phone numbers
+
+## Challenge Review
+
+We know you only have a limited time alloted to deliver this challenge, and thus
+will have to prioritize what you work on. A few things that are important for us
+and that will be considered during the review:
+- **documentation**: is the readme clear? are important parts of the code
+  documented?
+- **impact**: which features did you prioritize?
+- **maintainability**: is the code well-structured and easy to read/evolve?
+- **robustness**: is the code tested or easily testable? are edge-cases
+  considered? is static analysis leveraged?
+
+***
+
+Good luck, and enjoy!

ios/readme.md

@@ -5,42 +5,41 @@ Hands](https://hearthands.tech/).
 
 ## Why this challenge?
 
-Heart Hands is operating with a small team of dedicated and talented people. We
+Heart Hands is operating with a small team of dedicated & talented people. We
 are looking for seasoned engineers with a deep technical knowledge, strong
-understanding of their technical stack, and good product intuitions to join our
-team.
+understanding of their technical stack, and excellent product intuitions to join
+our team.
 
-This challenge has been designed to give a glimpse of what it is like to build a
+This exercise has been designed to give a glimpse of what it is like to build a
 messaging app, and the kind of technical challenges we face and care about. We
-are expecting you to spend no more than 48 hours on this.
+are expecting you to spend between 4 and 6 hours on this challenge.
 
-## Summary
+## Instructions
 
-You are tasked to develop a messaging app that allows to send and receive
-messages with several bots, each in their own chat.
+You are tasked with the implementation of an iOS messaging app that allows to
+communicate (send and receive text messages) with bots, each in their own 1:1
+chat.
 
-A server is available for you to use, you can read more about it in
-[`./server`](./server). The documentation contains informations on how it can be
-run and what kinds of API endpoints are available.
+A server is available for you to use. You can read more about it in
+[`./server`](./server). Its documentation contains informations on how it can be
+run, and what kinds of API endpoints & entities are available.
 
-## Requirements
-
-What are we expecting you to build?
+Functional requirements:
 
 - [ ] The app should start on a screen showing the list of all chats
 - [ ] The app should allow opening each chat individually
 - [ ] The app should allow sending messages to a chat
 - [ ] The app should reflect the messages sent to and received from the server
+- [ ] The app should be resilient to bad network conditions (drops & timeouts)
 
 ## Bonus
 
-What could be implemented to improve the UX?
+Some topics that we find interesting to dig:
 
 - [ ] Make the app work offline (both for app state and sending)
-- [ ] Make the app resilient to bad network conditions (retries & timeouts)
 - [ ] Make the app idempotent in regards to what you send and receive
 - [ ] Integrate a splashscreen to hide chats while the app is loading
-- [ ] Add support for optimisic sending to give instantaneity in the UI
+- [ ] Add support for optimistic sending to give instantaneity in the UI
 - [ ] Add support for a local read/unread indicator
 - [ ] Avoid block changing states so the app feels fluid & snappy
 - [ ] Make the app compatible to run on iPad and macOS
@@ -49,8 +48,23 @@ What could be implemented to improve the UX?
 
 ## Design
 
-We have prepared a design to help you during this challenge.
+We have prepared a design to help you during this challenge. You will also
+receive the Figma link along with the challenge instructions.
 
 ![design](./design.png)
 
+## Challenge Review
+
+We know you only have a limited time alloted to deliver this challenge, and thus
+will have to prioritize what you work on. A few things that are important for us
+and that will be considered during the review:
+- **documentation**: is the readme clear? are important parts of the code
+  documented?
+- **impact**: which features did you prioritize?
+- **maintainability**: is the code well-structured and easy to read/evolve?
+- **robustness**: is the code tested or easily testable? are edge-cases
+  considered? is static analysis leveraged?
+
+***
+
 Good luck, and enjoy!

ios/server/go.mod

@@ -1,16 +1,16 @@
 module github.com/hearthands/challenges/ios/server
 
-go 1.21.3
+go 1.21.4
 
 require (
 	github.com/go-chi/chi/v5 v5.0.10
 	github.com/go-chi/render v1.0.3
 	github.com/r3labs/sse/v2 v2.10.0
-	golang.org/x/exp v0.0.0-20231006140011-7918f672742d
+	golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa
 )
 
 require (
 	github.com/ajg/form v1.5.1 // indirect
-	golang.org/x/net v0.0.0-20191116160921-f9c825593386 // indirect
+	golang.org/x/net v0.18.0 // indirect
 	gopkg.in/cenkalti/backoff.v1 v1.1.0 // indirect
 )

ios/server/go.sum

@@ -16,8 +16,12 @@ github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
 golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
+golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa h1:FRnLl4eNAQl8hwxVVC17teOw8kdjVDVAiFMtgUdTSRQ=
+golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa/go.mod h1:zk2irFbV9DP96SEBUUAy67IdHUaZuSnrz1n472HUCLE=
 golang.org/x/net v0.0.0-20191116160921-f9c825593386 h1:ktbWvQrW08Txdxno1PiDpSxPXG6ndGsfnJjRRtkM0LQ=
 golang.org/x/net v0.0.0-20191116160921-f9c825593386/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.18.0 h1:mIYleuAkSbHh0tCv7RvjL3F6ZVbLjq4+R7zbOn3Kokg=
+golang.org/x/net v0.18.0/go.mod h1:/czyP5RqHAH4odGYxBJ1qz0+CE5WZ+2j1YgoEo8F2jQ=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 gopkg.in/cenkalti/backoff.v1 v1.1.0 h1:Arh75ttbsvlpVA7WtVpH4u9h6Zl46xuptxqLxPiSo4Y=

ios/server/main.go

@@ -21,9 +21,9 @@ import (
 )
 
 var (
-	hostname = envOrDefault("HOSTNAME", "localhost") // hostname used by the server
-	port     = envOrDefault("PORT", "3000")          // port used by the server
-	limit    = 100                                   // maximum number of entities returned in a single request
+	hostname = envOrDefault("HTTP_HOST", "localhost") // hostname used by the server
+	port     = envOrDefault("PORT", "3000")           // port used by the server
+	limit    = 100                                    // maximum number of entities returned in a single request
 )
 
 //go:embed data.json

ios/server/readme.md

@@ -1,23 +1,36 @@
 # iOS Challenge - Server Companion
 
 This server is used as a companion for the iOS challenge. Persistence is
-in-memory, restarting the server will reset its state.
+in-memory, and restarting the server will reset its state.
 
 The server will sometime be a bit capricious, you might observe:
 - failure to receive a response
-- server timing out when trying to send a message
+- timeouts when trying to send a message
 - duplicate events being received in the messages stream
 
 When that happens, you should retry and react accordingly.
 
 ## How to start the server?
 
 1. You need to install Go on your system: follow the [official documentation](https://go.dev/doc/install)
-2. Then execute the command: `go run .`
+2. Then, execute the command: `go run .`
+
+## How to make the server reachable from another machine?
+
+You might want to allow the server to be reached from another machine
+(simulator or a phone for example). One way to do that is to use [ngrok]().
+
+1. You need to install Ngrok on your system: follow the [official
+   documentation](https://ngrok.com/download)
+2. Then, after having started the server (see above), execute the command: `ngrok http 3000`
+
+This will give you a public URL of the form
+`https://9f98-62-194-145-77.ngrok.io`, that can be used to reach your server
+from any system that has an internet connection.
 
 ## API Documentation
 
-This API exposes a few HTTP endpoints, and an SSE stream. It allows to list
+This API exposes a few HTTP endpoints and an SSE stream. It allows to list
 chats, and read & write messages.
 
 ### Notes

readme.md

@@ -1,7 +1,7 @@
 # Challenges [![ci status](https://github.com/hearthandsinc/challenges/actions/workflows/ci.yml/badge.svg)](https://github.com/hearthandsinc/challenges/actions/workflows/ci.yml)
 
 This repository contains the [Heart Hands](https://hearthands.tech/) engineering
-challenges for [iOS](./ios) and _backend (soon)_.
+challenges for [iOS](./ios) and [backend](./backend) positions.
 
 ## Feedbacks