Assignment

.env

@@ -0,0 +1,2 @@
+REDIS_URL=redis://127.0.0.1:6379
+REDIS_DATABASE=0

.env.example

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+# Environment Configuration
+# Copy this file to .env in your project root
+
+# Cache Configuration
+FORCE_FRESH_LATEST=true
+
+# Optional: Override cache durations
+# DEFAULT_CACHE_MS=300000
+# LATEST_BLOCK_CACHE_MS=60000
+
+# Development vs Production
+# FORCE_FRESH_LATEST=false  # For development (faster)
+# FORCE_FRESH_LATEST=true   # For production (accurate)

.gitignore

@@ -1,5 +1,5 @@
-# dependencies
-/node_modules
-.esbuild
-/.idea/modules.xml
-/.idea/backend-assignment-btcenergy.iml
+# dependencies
+/node_modules
+.esbuild
+/.idea/modules.xml
+/.idea/backend-assignment-btcenergy.iml

.nvmrc

@@ -1 +1 @@
-16
+16

.vscode/launch.json

@@ -0,0 +1,49 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Debug Serverless Offline",
+      "type": "node",
+      "request": "launch",
+      "program": "${workspaceFolder}/node_modules/.bin/serverless",
+      "args": [
+        "offline",
+        "start",
+        "--httpPort=4000",
+        "--host=0.0.0.0"
+      ],
+      "cwd": "${workspaceFolder}",
+      "env": {
+        "NODE_OPTIONS": "--inspect=9230"
+      },
+      "console": "integratedTerminal",
+      "autoAttachChildProcesses": true,
+      "skipFiles": [
+        "<node_internals>/**"
+      ],
+      "sourceMaps": true,
+      "outFiles": [
+        "${workspaceFolder}/**/*.js"
+      ],
+      "resolveSourceMapLocations": [
+        "${workspaceFolder}/**",
+        "!**/node_modules/**"
+      ]
+    },
+    {
+      "name": "Attach to Serverless",
+      "type": "node",
+      "request": "attach",
+      "port": 9230,
+      "localRoot": "${workspaceFolder}",
+      "remoteRoot": "${workspaceFolder}",
+      "skipFiles": [
+        "<node_internals>/**"
+      ],
+      "sourceMaps": true,
+      "outFiles": [
+        "${workspaceFolder}/**/*.js"
+      ]
+    }
+  ]
+}

.vscode/tasks.json

@@ -0,0 +1,34 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "type": "npm",
+      "script": "compile",
+      "group": "build",
+      "label": "npm: compile",
+      "detail": "tsc -p . --noEmit"
+    },
+    {
+      "type": "npm",
+      "script": "debug",
+      "group": "build",
+      "label": "npm: debug",
+      "detail": "node --inspect=9229 node_modules/serverless/bin/serverless.js offline start --httpPort=4000 --host=0.0.0.0",
+      "isBackground": true,
+      "problemMatcher": {
+        "pattern": {
+          "regexp": "^\\s*at\\s+(.*?)\\s+\\((.*?):(\\d+):(\\d+)\\)$",
+          "file": 2,
+          "line": 3,
+          "column": 4,
+          "message": 1
+        },
+        "background": {
+          "activeOnStart": true,
+          "beginsPattern": "^.*Serverless: Starting Offline.*$",
+          "endsPattern": "^.*offline: Offline \\[http for lambda\\] listening on.*$"
+        }
+      }
+    }
+  ]
+}

README.md

@@ -1,96 +1,95 @@
-# Backend Engineer Technical Assignment
-## Introduction
-This assessment aims to assess the technical, analytical, and collaboration skills of
-the candidates for backend development positions in Sensorfact.
-
-In this assignment, we included a few of the technologies that we use in our
-existing products:
-
-- **GraphQL:**
-  Within Sensorfact we expose most of our data regarding measurements, machine
-  specific configuration and industry knowledge via a GraphQL API.
-- **TypeScript:**
-  A big part of our code is written in plain JavaScript. All
-  new projects use TypeScript, because we like the benefits that the type system
-  offers us during development, reviews, and testing.
-
-## Process & Guidelines
-
->- **We aim to timebox the assignment to 4 hours**, but feel free to dedicate as much time as you consider necessary
->- Make a conscious decision on what you want to focus on: it's ok if you
-   cannot complete the entire assignment.
->- Send us your solution before the technical interview: link to a repository.
-   You can, for example, fork this repository.
->- The assignment includes a description of a problem to solve, which could potentially lack
-   details. Feel free to make assumptions if needed, or contact us for clarification if you consider it necessary.
->- Take this assignment as an opportunity to show us your style: what you like to
-   work on, what you find important, how you address problems,etc.
->- Feel free to use any tool you'd like, that includes AI assistants as well.
-   We want you to work with the tools you know from your Day2Day work but expect us to dive deep with you into   the decision making behind adding / using certain logic.
->- **During the technical interview, we invite you to present your solution and discuss
-   it together as a team**: which decisions you took and why, questions about specific parts of the code,
-   libraries you have used, how easy and maintainable is the code,etc.
-
-## Problem to solve (an imaginary one, of course ;))
-
-Sustainability is starting to take a key role in every product or solution launched into the market, and software
-systems are not an exception. It is not enough anymore to create and deploy in time complex and innovative
-systems which bring value to customers; they also need to be efficient. They need to
-be sustainable and consume the minimum amount of resources in their operations.
-
-As you probably have heard, one of the principal arguments against using Bitcoin is the amount of energy needed to keep
-the system running. To evaluate the sustainability of the blockchain network in which Bitcoin runs, we
-want to create a platform to monitor the energy spent on financial transactions using Bitcoin.
-
-The platform will visualize the energy consumed by the network and potentially calculate energy waste. Our frontend
-development team will need an API (preferably GraphQL) to connect to which will provide this information. The platform should
-be able to perform the following operations (already sorted by priority):
-
-- Provide the energy consumption per transaction for a specific block.
-- Provide the total energy consumption per day in the last `x` number of days.
-- Advanced Feature: Optimize the number of calls made to the Blockchain API to avoid asking for the
-  same information multiple times.
-- Expert Feature: Provide the total energy consumption of all transactions performed by a specific wallet address.
-
-Even if it is too soon in the product's lifetime to think about non-functional requirements, it will be beneficial to
-build it considering that we hope to scale the solution and avoid significant refactoring.
-
-## Assumptions
-
-**- You can use a simple model of the BTC network: the network is composed of blocks (each block identified by a unique `hash` value
-or a block index). Each block contains a set of transactions, each transaction also has a unique `hash` by which it can be identified.**
-- Every transaction takes up a variable amount of storage space inside the block, indicated by the `size` field (in bytes).
-- Assume that the energy cost per byte is 4,56 KwH.
-- You can use the public Blockchain API from blockchain.com to retrieve information
-  (https://www.blockchain.com/explorer/api/blockchain_api), for example:
-    - Latest block: https://blockchain.info/latestblock
-    - Information of blocks in a day: https://blockchain.info/blocks/$time_in_milliseconds?format=json
-    - Information of a single block: https://blockchain.info/rawblock/$block_hash
-    - Information of a single transaction: https://blockchain.info/rawtx/$tx_hash
-    - Information on transactions for a specific wallet address: https://blockchain.info/rawaddr/$bitcoin_address
-
-## Project code
-This project is comes with a pre-configured GraphQL server, hosted as a serverless
-function to get you started on the assignment. However, feel free to write your
-own implementation if you prefer.
-
-## Running the project
-Requirements:
-- NodeJS 16.x (run `nvm use` in root folder)
-- Yarn cli
-- Serverless framework: run `npm install -g serverless`
-
-Install dependencies:
-
-```sh
-yarn
-```
-
-Run the serverless function in offline mode:
-
-```sh
-yarn start
-```
-
-The server will be ready at: `http://localhost:4000/graphql`
-
+# Backend Engineer Technical Assignment
+## Introduction
+This assessment aims to assess the technical, analytical, and collaboration skills of
+the candidates for backend development positions in Sensorfact.
+
+In this assignment, we included a few of the technologies that we use in our
+existing products:
+
+- **GraphQL:**
+  Within Sensorfact we expose most of our data regarding measurements, machine
+  specific configuration and industry knowledge via a GraphQL API.
+- **TypeScript:**
+  A big part of our code is written in plain JavaScript. All
+  new projects use TypeScript, because we like the benefits that the type system
+  offers us during development, reviews, and testing.
+
+## Process & Guidelines
+
+>- **We aim to timebox the assignment to 4 hours**, but feel free to dedicate as much time as you consider necessary
+>- Make a conscious decision on what you want to focus on: it's ok if you
+   cannot complete the entire assignment.
+>- Send us your solution before the technical interview: link to a repository.
+   You can, for example, fork this repository.
+>- The assignment includes a description of a problem to solve, which could potentially lack
+   details. Feel free to make assumptions if needed, or contact us for clarification if you consider it necessary.
+>- Take this assignment as an opportunity to show us your style: what you like to
+   work on, what you find important, how you address problems,etc.
+>- Feel free to use any tool you'd like, that includes AI assistants as well.
+   We want you to work with the tools you know from your Day2Day work but expect us to dive deep with you into   the decision making behind adding / using certain logic.
+>- **During the technical interview, we invite you to present your solution and discuss
+   it together as a team**: which decisions you took and why, questions about specific parts of the code,
+   libraries you have used, how easy and maintainable is the code,etc.
+
+## Problem to solve (an imaginary one, of course ;))
+
+Sustainability is starting to take a key role in every product or solution launched into the market, and software
+systems are not an exception. It is not enough anymore to create and deploy in time complex and innovative
+systems which bring value to customers; they also need to be efficient. They need to
+be sustainable and consume the minimum amount of resources in their operations.
+
+As you probably have heard, one of the principal arguments against using Bitcoin is the amount of energy needed to keep
+the system running. To evaluate the sustainability of the blockchain network in which Bitcoin runs, we
+want to create a platform to monitor the energy spent on financial transactions using Bitcoin.
+
+The platform will visualize the energy consumed by the network and potentially calculate energy waste. Our frontend
+development team will need an API (preferably GraphQL) to connect to which will provide this information. The platform should
+be able to perform the following operations (already sorted by priority):
+
+- Provide the energy consumption per transaction for a specific block.
+- Provide the total energy consumption per day in the last `x` number of days.
+- Advanced Feature: Optimize the number of calls made to the Blockchain API to avoid asking for the
+  same information multiple times.
+- Expert Feature: Provide the total energy consumption of all transactions performed by a specific wallet address.
+
+Even if it is too soon in the product's lifetime to think about non-functional requirements, it will be beneficial to
+build it considering that we hope to scale the solution and avoid significant refactoring.
+
+## Assumptions
+
+**- You can use a simple model of the BTC network: the network is composed of blocks (each block identified by a unique `hash` value
+or a block index). Each block contains a set of transactions, each transaction also has a unique `hash` by which it can be identified.**
+- Every transaction takes up a variable amount of storage space inside the block, indicated by the `size` field (in bytes).
+- Assume that the energy cost per byte is 4,56 KwH.
+- You can use the public Blockchain API from blockchain.com to retrieve information
+  (https://www.blockchain.com/explorer/api/blockchain_api), for example:
+    - Latest block: https://blockchain.info/latestblock
+    - Information of blocks in a day: https://blockchain.info/blocks/$time_in_milliseconds?format=json
+    - Information of a single block: https://blockchain.info/rawblock/$block_hash
+    - Information of a single transaction: https://blockchain.info/rawtx/$tx_hash
+    - Information on transactions for a specific wallet address: https://blockchain.info/rawaddr/$bitcoin_address
+
+## Project code
+This project is comes with a pre-configured GraphQL server, hosted as a serverless
+function to get you started on the assignment. However, feel free to write your
+own implementation if you prefer.
+
+## Running the project
+Requirements:
+- NodeJS 16.x (run `nvm use` in root folder)
+- Yarn cli
+- Serverless framework: run `npm install -g serverless`
+
+Install dependencies:
+
+```sh
+yarn
+```
+
+Run the serverless function in offline mode:
+
+```sh
+yarn start
+```
+
+The server will be ready at: `http://localhost:4000/graphql`