Transaction Management Backend - Level 1

Below, you'll find the instructions for getting started with your task. Please read them carefully to avoid unexpected issues. Best of luck!

Time estimate

Between 2 and 3 hours, plus the time to set up the codebase.

Mandatory steps before you get started

1. Set up your codebase according to either of the outlined options for your coding test.
2. Learn how to get help if you run into an issue with your coding test.

The task

Your task is to build a backend app that allows the recording of financial transactions and viewing the transaction history.

It should implement the Transaction Management API specification, which is defined in the Open API format.

Transaction Management API Specification

{
  "openapi": "3.0.0",
  "info": {
    "title": "Transaction Management API",
    "version": "3.1.0"
  },
  "components": {
    "schemas": {
      "TransactionRequest": {
        "type": "object",
        "properties": {
          "account_id": {
            "type": "string",
            "format": "uuid"
          },
          "amount": {
            "type": "integer"
          }
        },
        "required": [
          "transaction_id",
          "account_id",
          "amount"
        ]
      },
      "Transaction": {
        "type": "object",
        "properties": {
          "transaction_id": {
            "type": "string",
            "format": "uuid"
          },
          "account_id": {
            "type": "string",
            "format": "uuid"
          },
          "amount": {
            "type": "integer"
          },
          "created_at": {
            "type": "string",
            "format": "date-time"
          }
        },
        "required": [
          "transaction_id",
          "account_id",
          "amount",
          "created_at"
        ]
      },
      "ArrayOfTransactions": {
        "type": "array",
        "items": {
          "$ref": "#/components/schemas/Transaction"
        }
      },
      "Account": {
        "type": "object",
        "properties": {
          "account_id": {
            "type": "string",
            "format": "uuid"
          },
          "balance": {
            "type": "integer"
          }
        },
        "required": [
          "account_id",
          "balance"
        ]
      }
    },
    "examples": {
      "TransactionRequestWithPositiveAmount": {
        "value": {
          "account_id": "0afd02d3-6c59-46e7-b7bc-893c5e0b7ac2",
          "amount": 7
        }
      },
      "TransactionRequestWithNegativeAmount": {
        "value": {
          "account_id": "5ae0ef78-e902-4c40-9f53-8cf910587312",
          "amount": -4
        }
      },
      "TransactionWithPositiveAmount": {
        "value": {
          "transaction_id": "4bcc3959-6fe1-406e-9f04-cad2637b47d5",
          "account_id": "0afd02d3-6c59-46e7-b7bc-893c5e0b7ac2",
          "amount": 7,
          "created_at": "2021-05-12T18:29:40.206924+00:00"
        }
      },
      "TransactionWithNegativeAmount": {
        "value": {
          "transaction_id": "050a75f6-8df1-4ad1-8f5b-54e821e98581",
          "account_id": "5ae0ef78-e902-4c40-9f53-8cf910587312",
          "amount": -4,
          "created_at": "2021-05-18T21:33:47.203136+00:00"
        }
      },
      "ArrayOfTransactionsExample": {
        "value": [
          {
            "transaction_id": "4bcc3959-6fe1-406e-9f04-cad2637b47d5",
            "account_id": "0afd02d3-6c59-46e7-b7bc-893c5e0b7ac2",
            "amount": 7,
            "created_at": "2021-05-12T18:29:40.206924+00:00"
          },
          {
            "transaction_id": "050a75f6-8df1-4ad1-8f5b-54e821e98581",
            "account_id": "5ae0ef78-e902-4c40-9f53-8cf910587312",
            "amount": -4,
            "created_at": "2021-05-18T21:33:47.203136+00:00"
          }
        ]
      },
      "PositiveAccount": {
        "value": {
          "account_id": "fbf4a552-2418-46c5-b308-6094ddc493a1",
          "balance": 10
        }
      },
      "NegativeAccount": {
        "value": {
          "account_id": "9c3cd9a8-65c4-4d26-8488-ef9a40f57c37",
          "balance": -7
        }
      },
      "MaxTransactionVolumeExample": {
        "value": {
          "maxVolume": 4,
          "accountIds": [
            "44a92331-a533-4dd3-82e3-3ff75219e33b",
            "7c9be9e8-a6df-4f43-9a44-38c10ad0de4a"
          ]
        }
      }
    }
  },
  "paths": {
    "/ping": {
      "get": {
        "summary": "Healhcheck to make sure the service is up.",
        "responses": {
          "200": {
            "description": "The service is up and running."
          }
        }
      }
    },
    "/transactions": {
      "post": {
        "summary": "Creates a new transaction.",
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/TransactionRequest"
              },
              "examples": {
                "TransactionRequestWithPositiveAmount": {
                  "$ref": "#/components/examples/TransactionRequestWithPositiveAmount"
                },
                "TransactionRequestWithNegativeAmount": {
                  "$ref": "#/components/examples/TransactionRequestWithNegativeAmount"
                }
              }
            }
          }
        },
        "responses": {
          "201": {
            "description": "Transaction created.",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Transaction"
                },
                "examples": {
                  "TransactionWithPositiveAmount": {
                    "$ref": "#/components/examples/TransactionWithPositiveAmount"
                  }
                }
              }
            }
          },
          "400": {
            "description": "Mandatory body parameters missing or have incorrect type."
          },
          "405": {
            "description": "Specified HTTP method not allowed."
          },
          "415": {
            "description": "Specified content type not allowed."
          }
        }
      },
      "get": {
        "summary": "Get transactions",
        "responses": {
          "200": {
            "description": "Returns all previously created transactions.",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/ArrayOfTransactions"
                },
                "examples": {
                  "ArrayOfTransactionsExample": {
                    "$ref": "#/components/examples/ArrayOfTransactionsExample"
                  }
                }
              }
            }
          }
        }
      }
    },
    "/transactions/{transaction_id}": {
      "get": {
        "summary": "Returns the transaction by id.",
        "parameters": [
          {
            "name": "transaction_id",
            "in": "path",
            "required": true,
            "description": "Transaction ID",
            "schema": {
              "type": "string",
              "format": "uuid"
            },
            "example": "023d2024-24bc-42c9-ab24-689eef6ea0f9"
          }
        ],
        "responses": {
          "200": {
            "description": "Transaction details.",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Transaction"
                },
                "examples": {
                  "TransactionWithPositiveAmount": {
                    "$ref": "#/components/examples/TransactionWithPositiveAmount"
                  },
                  "TransactionWithNegativeAmount": {
                    "$ref": "#/components/examples/TransactionWithNegativeAmount"
                  }
                }
              }
            }
          },
          "400": {
            "description": "transaction_id missing or has incorrect type."
          },
          "404": {
            "description": "Transaction not found"
          }
        }
      }
    },
    "/accounts/{account_id}": {
      "get": {
        "summary": "Returns the account data.",
        "parameters": [
          {
            "name": "account_id",
            "in": "path",
            "required": true,
            "description": "Account ID.",
            "schema": {
              "type": "string",
              "format": "uuid"
            },
            "example": "5ba6e1b0-e3e7-483a-919a-a2fc17629a90"
          }
        ],
        "responses": {
          "200": {
            "description": "Account data.",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Account"
                },
                "examples": {
                  "PositiveAccount": {
                    "$ref": "#/components/examples/PositiveAccount"
                  },
                  "NegativeAccount": {
                    "$ref": "#/components/examples/NegativeAccount"
                  }
                }
              }
            }
          },
          "400": {
            "description": "account_id missing or has incorrect type."
          },
          "404": {
            "description": "Account not found."
          }
        }
      }
    }
  }
}

Please agree with your hiring team regarding the tech stack choice.

Solution expectations

• Do your best to make the provided E2E tests pass. Check out this tutorial to learn how to execute these tests and analyze the results.
• Keep server data in a SQLite database. We want to see how you design the database schema and SQL queries.

When you are done

1. Create a new Pull Request from the branch where you've committed your solution to the default branch of this repository. Please do not merge the created Pull Request.
2. Go to your application in Alva Labs and submit your test.

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