diff --git a/node_modules/.yarn-integrity b/node_modules/.yarn-integrity
new file mode 100644
index 0000000000..b9b7edf672
--- /dev/null
+++ b/node_modules/.yarn-integrity
@@ -0,0 +1,10 @@
+{
+  "systemParams": "darwin-x64-115",
+  "modulesFolders": [],
+  "flags": [],
+  "linkedModules": [],
+  "topLevelPatterns": [],
+  "lockfileEntries": {},
+  "files": [],
+  "artifacts": {}
+}
\ No newline at end of file
diff --git a/src/cli/args.js b/src/cli/args.js
index 8283f7f7aa..a36a4f40fe 100644
--- a/src/cli/args.js
+++ b/src/cli/args.js
@@ -1,5 +1,17 @@
 const parseArgs = () => {
-    // Write your code here 
+  // Skip the first two elements (node and script path)
+  const args = process.argv.slice(2);
+
+  const parsedArgs = [];
+
+  // why i += 2 -> [ '--some-arg', 'value1', '--other', '1337', '--arg2', '42' ]
+  for (let i = 0; i < args.length; i += 2) {
+    const propName = args[i].replace("--", "");
+    const value = args[i + 1];
+    parsedArgs.push(`${propName} is ${value}`);
+  }
+
+  console.log(parsedArgs.join(", "));
 };
 
-parseArgs();
\ No newline at end of file
+parseArgs();
diff --git a/src/cli/env.js b/src/cli/env.js
index fe4aa4a8df..b3fe5e62b4 100644
--- a/src/cli/env.js
+++ b/src/cli/env.js
@@ -1,5 +1,12 @@
 const parseEnv = () => {
-    // Write your code here 
+  const envVars = process.env;
+  console.log("Object.keys(envVars)", Object.keys(envVars));
+  const rssVars = Object.keys(envVars)
+    .filter((key) => key.startsWith("RSS_"))
+    .map((key) => `${key}=${envVars[key]}`)
+    .join("; ");
+
+  console.log(rssVars);
 };
 
-parseEnv();
\ No newline at end of file
+parseEnv();
diff --git a/src/cp/cp.js b/src/cp/cp.js
index 4a87b98c55..7e0c668488 100644
--- a/src/cp/cp.js
+++ b/src/cp/cp.js
@@ -1,6 +1,21 @@
+import { spawn } from "child_process";
+
 const spawnChildProcess = async (args) => {
-    // Write your code here
+  const child = spawn("node", ["./src/cp/files/script.js", ...args]);
+
+  process.stdin.pipe(child.stdin);
+
+  child.stdout.pipe(process.stdout);
+
+  child.on("error", (error) => {
+    console.error(`Error: ${error.message}`);
+  });
+
+  child.on("exit", (code) => {
+    console.log(`Child process exited with code ${code}`);
+  });
 };
 
+const args = process.argv.slice(2);
 // Put your arguments in function call to test this functionality
-spawnChildProcess( /* [someArgument1, someArgument2, ...] */);
+spawnChildProcess(args);
diff --git a/src/cp/files/script.js b/src/cp/files/script.js
index 44a0622fbc..4d4494a7a2 100644
--- a/src/cp/files/script.js
+++ b/src/cp/files/script.js
@@ -4,9 +4,9 @@ console.log(`Total number of arguments is ${args.length}`);
 console.log(`Arguments: ${JSON.stringify(args)}`);
 
 const echoInput = (chunk) => {
-    const chunkStringified = chunk.toString();
-    if (chunkStringified.includes('CLOSE')) process.exit(0);
-    process.stdout.write(`Received from master process: ${chunk.toString()}\n`)
+  const chunkStringified = chunk.toString();
+  if (chunkStringified.includes("CLOSE")) process.exit(0);
+  process.stdout.write(`Received from master process: ${chunk.toString()}\n`);
 };
 
-process.stdin.on('data', echoInput);
+process.stdin.on("data", echoInput);
diff --git a/src/fs/copy.js b/src/fs/copy.js
index bd17fe3991..d95db0f6d0 100644
--- a/src/fs/copy.js
+++ b/src/fs/copy.js
@@ -1,5 +1,30 @@
+import { promises as fs } from "fs";
+import path from "path";
+
 const copy = async () => {
-    // Write your code here 
+  const folder = "src/fs/";
+  const sourceDir = path.join(folder, "files");
+  const targetDir = path.join(folder, "files_copy");
+
+  try {
+    await fs.access(sourceDir);
+
+    try {
+      await fs.access(targetDir);
+      throw new Error("FS operation failed: Target directory already exists");
+    } catch {}
+
+    await fs.mkdir(targetDir);
+
+    const files = await fs.readdir(sourceDir);
+    for (const file of files) {
+      const srcFile = path.join(sourceDir, file);
+      const destFile = path.join(targetDir, file);
+      await fs.copyFile(srcFile, destFile);
+    }
+  } catch (error) {
+    throw new Error(`FS operation failed: ${error}`);
+  }
 };
 
 await copy();
diff --git a/src/fs/create.js b/src/fs/create.js
index 8d18cf9fc2..58f9079bb7 100644
--- a/src/fs/create.js
+++ b/src/fs/create.js
@@ -1,5 +1,35 @@
+import { promises as fs } from "fs";
+import path from "path";
+
 const create = async () => {
-    // Write your code here 
+  const folder = "src/fs/files";
+  const pathToFolder = path.join(folder, "fresh.txt");
+  const text = "I am fresh and young";
+
+  let folderExists = true;
+  try {
+    await fs.access(folder, fs.constants.R_OK);
+  } catch {
+    folderExists = false;
+  }
+
+  if (!folderExists) {
+    await fs.mkdir(folder);
+  }
+
+  let fileExists = true;
+  try {
+    await fs.access(pathToFolder);
+  } catch {
+    fileExists = false;
+  }
+
+  if (!fileExists) {
+    await fs.writeFile(pathToFolder, text, "utf-8");
+    console.log("File created successfully.");
+  } else {
+    console.error("FS operation failed: File already exists");
+  }
 };
 
-await create();
\ No newline at end of file
+await create();
diff --git a/src/fs/delete.js b/src/fs/delete.js
index 4718dbc4c5..a27ca3cfd0 100644
--- a/src/fs/delete.js
+++ b/src/fs/delete.js
@@ -1,5 +1,17 @@
-const remove = async () => {
-    // Write your code here 
+import { promises as fs } from "fs";
+import path from "path";
+
+const removeFile = async () => {
+  const folder = "src/fs/files/";
+  const fileToRemove = path.join(folder, "fileToRemove.txt");
+
+  try {
+    await fs.access(fileToRemove);
+
+    await fs.unlink(fileToRemove);
+  } catch (error) {
+    throw new Error(`FS operation failed: ${error.message}`);
+  }
 };
 
-await remove();
\ No newline at end of file
+await removeFile();
diff --git a/src/fs/list.js b/src/fs/list.js
index c0a83dea15..5f9e660282 100644
--- a/src/fs/list.js
+++ b/src/fs/list.js
@@ -1,5 +1,19 @@
-const list = async () => {
-    // Write your code here 
+import { promises as fs } from "fs";
+import path from "path";
+
+const listFiles = async () => {
+  const folder = "src/fs/";
+
+  const filesFolder = path.join(folder, "files");
+
+  try {
+    await fs.access(filesFolder);
+
+    const filenames = await fs.readdir(filesFolder);
+    console.log(filenames);
+  } catch (error) {
+    throw new Error(`FS operation failed: ${error.message}`);
+  }
 };
 
-await list();
\ No newline at end of file
+await listFiles();
diff --git a/src/fs/read.js b/src/fs/read.js
index 52c78cc6ee..4e2cd51ae9 100644
--- a/src/fs/read.js
+++ b/src/fs/read.js
@@ -1,5 +1,18 @@
-const read = async () => {
-    // Write your code here 
+import { promises as fs } from "fs";
+import path from "path";
+
+const readFile = async () => {
+  const folder = "src/fs/files";
+  const fileToRead = path.join(folder, "fileToRead.txt");
+
+  try {
+    await fs.access(fileToRead);
+
+    const content = await fs.readFile(fileToRead, "utf8");
+    console.log(content);
+  } catch (error) {
+    throw new Error(`FS operation failed: ${error.message}`);
+  }
 };
 
-await read();
\ No newline at end of file
+await readFile();
diff --git a/src/fs/rename.js b/src/fs/rename.js
index 2bb99ecdb5..ddcbe5b896 100644
--- a/src/fs/rename.js
+++ b/src/fs/rename.js
@@ -1,5 +1,23 @@
-const rename = async () => {
-    // Write your code here 
+import { promises as fs } from "fs";
+import path from "path";
+
+const renameFile = async () => {
+  const folder = "src/fs/files/";
+  const sourceFile = path.join(folder, "wrongFilename.txt");
+  const targetFile = path.join(folder, "properFilename.md");
+
+  try {
+    await fs.access(sourceFile);
+
+    try {
+      await fs.access(targetFile);
+      throw new Error("FS operation failed: properFilename.md already exists");
+    } catch {}
+
+    await fs.rename(sourceFile, targetFile);
+  } catch (error) {
+    throw new Error(`FS operation failed: ${error.message}`);
+  }
 };
 
-await rename();
\ No newline at end of file
+await renameFile();
diff --git a/src/hash/calcHash.js b/src/hash/calcHash.js
index 450f8f72e2..cd3ba59f29 100644
--- a/src/hash/calcHash.js
+++ b/src/hash/calcHash.js
@@ -1,5 +1,22 @@
+import crypto from "crypto";
+import fs from "fs";
+
 const calculateHash = async () => {
-    // Write your code here 
+  const hash = crypto.createHash("sha256");
+
+  try {
+    const hashDigest = hash.digest("hex");
+
+    await fs.promises.writeFile(
+      "src/hash/files/fileToCalculateHashFor.txt",
+      hashDigest,
+      "utf-8"
+    );
+
+    console.log(`Hash calculated successfully: ${hashDigest}`);
+  } catch (error) {
+    console.error("Error calculating hash:", error);
+  }
 };
 
-await calculateHash();
\ No newline at end of file
+await calculateHash();
diff --git a/src/modules/cjsToEsm.cjs b/src/modules/cjsToEsm.cjs
deleted file mode 100644
index 8b7be2a48b..0000000000
--- a/src/modules/cjsToEsm.cjs
+++ /dev/null
@@ -1,40 +0,0 @@
-const path = require('path');
-const { release, version } = require('os');
-const { createServer: createServerHttp } = require('http');
-require('./files/c');
-
-const random = Math.random();
-
-let unknownObject;
-
-if (random > 0.5) {
-    unknownObject = require('./files/a.json');
-} else {
-    unknownObject = require('./files/b.json');
-}
-
-console.log(`Release ${release()}`);
-console.log(`Version ${version()}`);
-console.log(`Path segment separator is "${path.sep}"`);
-
-console.log(`Path to current file is ${__filename}`);
-console.log(`Path to current directory is ${__dirname}`);
-
-const myServer = createServerHttp((_, res) => {
-    res.end('Request accepted');
-});
-
-const PORT = 3000;
-
-console.log(unknownObject);
-
-myServer.listen(PORT, () => {
-    console.log(`Server is listening on port ${PORT}`);
-    console.log('To terminate it, use Ctrl+C combination');
-});
-
-module.exports = {
-    unknownObject,
-    myServer,
-};
-
diff --git a/src/modules/esm.mjs b/src/modules/esm.mjs
new file mode 100644
index 0000000000..f075f10da9
--- /dev/null
+++ b/src/modules/esm.mjs
@@ -0,0 +1,42 @@
+import path from "path";
+import { release, version } from "os";
+import { createServer as createServerHttp } from "http";
+import { fileURLToPath } from "url";
+
+import "./files/c.js";
+
+const random = Math.random();
+
+let unknownObject;
+
+if (random > 0.5) {
+  unknownObject = import("./files/a.json", { assert: { type: "json" } });
+} else {
+  unknownObject = import("./files/b.json", { assert: { type: "json" } });
+}
+
+console.log(`Release ${release()}`);
+console.log(`Version ${version()}`);
+console.log(`Path segment separator is "${path.sep}"`);
+
+console.log(`Path to current file is ${fileURLToPath(import.meta.url)}`);
+console.log(`Path to current directory is ${fileURLToPath(import.meta.url)}`);
+
+const myServer = createServerHttp((_, res) => {
+  res.end("Request accepted");
+});
+
+const PORT = 3000;
+
+console.log(unknownObject);
+
+unknownObject.then((unknownObjectModule) => {
+  console.log(unknownObjectModule.default);
+
+  myServer.listen(PORT, () => {
+    console.log(`Server is listening on port ${PORT}`);
+    console.log("To terminate it, use Ctrl+C combination");
+  });
+});
+
+export { unknownObject, myServer };
diff --git a/src/streams/read.js b/src/streams/read.js
index 52c78cc6ee..463165d474 100644
--- a/src/streams/read.js
+++ b/src/streams/read.js
@@ -1,5 +1,12 @@
+import fs from "fs";
+
 const read = async () => {
-    // Write your code here 
+  const readableStream = fs.createReadStream(
+    "src/streams/files/fileToRead.txt",
+    "utf8"
+  );
+
+  readableStream.pipe(process.stdout);
 };
 
-await read();
\ No newline at end of file
+await read();
diff --git a/src/streams/transform.js b/src/streams/transform.js
index 315fc6597f..73e5c6e6e5 100644
--- a/src/streams/transform.js
+++ b/src/streams/transform.js
@@ -1,5 +1,21 @@
+import { Transform, pipeline } from "stream";
+import { promisify } from "util";
+
+const pipelineAsync = promisify(pipeline);
+
+const reverseTextTransform = new Transform({
+  transform(chunk, _, cl) {
+    const reversed = chunk.toString().split("").reverse().join("");
+    cl(null, reversed);
+  },
+});
+
 const transform = async () => {
-    // Write your code here 
+  try {
+    await pipelineAsync(process.stdin, reverseTextTransform, process.stdout);
+  } catch (error) {
+    console.error("An error occurred:", error);
+  }
 };
 
-await transform();
\ No newline at end of file
+transform();
diff --git a/src/streams/write.js b/src/streams/write.js
index fc917160a2..5e918e88f3 100644
--- a/src/streams/write.js
+++ b/src/streams/write.js
@@ -1,5 +1,20 @@
+import fs from "fs";
+
 const write = async () => {
-    // Write your code here 
+  const writableStream = fs.createWriteStream(
+    "src/streams/files/fileToWrite.txt",
+    "utf8"
+  );
+
+  process.stdin.pipe(writableStream);
+
+  process.stdin.on("end", () => {
+    writableStream.end();
+  });
+
+  console.log(
+    "Type something and press Enter to write to the file. Press Ctrl+D to end."
+  );
 };
 
-await write();
\ No newline at end of file
+await write();
diff --git a/src/wt/main.js b/src/wt/main.js
index 37d80484ec..fa22dfcda2 100644
--- a/src/wt/main.js
+++ b/src/wt/main.js
@@ -1,5 +1,43 @@
+import { Worker } from "worker_threads";
+import os from "os";
+
 const performCalculations = async () => {
-    // Write your code here
+  const numCores = os.cpus().length;
+  const results = [];
+  const promises = [];
+
+  for (let i = 0; i < numCores; i++) {
+    const promise = new Promise((resolve, reject) => {
+      const worker = new Worker("./src/wt/worker.js");
+      const valueToSend = 10 + i;
+
+      worker.postMessage(valueToSend);
+
+      worker.on("message", (result) => {
+        results.push({ status: "resolved", data: result });
+        resolve();
+        worker.terminate();
+      });
+
+      worker.on("error", (error) => {
+        console.error(`Worker error: ${error}`);
+        results.push({ status: "error", data: null });
+        reject(error);
+        worker.terminate();
+      });
+
+      worker.on("exit", (code) => {
+        if (code !== 0) {
+          console.error(`Worker stopped with exit code: ${code}`);
+        }
+      });
+    });
+
+    promises.push(promise);
+  }
+
+  await Promise.all(promises);
+  console.log(results);
 };
 
-await performCalculations();
\ No newline at end of file
+await performCalculations();
diff --git a/src/wt/worker.js b/src/wt/worker.js
index 441b2154f8..121bf7c30c 100644
--- a/src/wt/worker.js
+++ b/src/wt/worker.js
@@ -1,8 +1,13 @@
-// n should be received from main thread
-const nthFibonacci = (n) => n < 2 ? n : nthFibonacci(n - 1) + nthFibonacci(n - 2);
+import { parentPort } from "worker_threads";
 
-const sendResult = () => {
-    // This function sends result of nthFibonacci computations to main thread
+const nthFibonacci = (n) =>
+  n < 2 ? n : nthFibonacci(n - 1) + nthFibonacci(n - 2);
+
+const sendResult = (result) => {
+  parentPort.postMessage(result);
 };
 
-sendResult();
\ No newline at end of file
+parentPort.on("message", (n) => {
+  const result = nthFibonacci(n);
+  sendResult(result);
+});
diff --git a/src/zip/compress.js b/src/zip/compress.js
index bb328f43c6..4548a84687 100644
--- a/src/zip/compress.js
+++ b/src/zip/compress.js
@@ -1,5 +1,13 @@
+import fs from "fs";
+import zlib from "zlib";
+
 const compress = async () => {
-    // Write your code here 
+  const readableStream = fs.createReadStream(
+    "src/zip/files/fileToCompress.txt"
+  );
+  const writableStream = fs.createWriteStream("src/zip/files/archive.gz");
+  const gzip = zlib.createGzip();
+  readableStream.pipe(gzip).pipe(writableStream);
 };
 
-await compress();
\ No newline at end of file
+await compress();
diff --git a/src/zip/decompress.js b/src/zip/decompress.js
index 69f6c345f8..371a940d25 100644
--- a/src/zip/decompress.js
+++ b/src/zip/decompress.js
@@ -1,5 +1,13 @@
+import fs from "fs";
+import zlib from "zlib";
+
 const decompress = async () => {
-    // Write your code here 
+  const readableStream = fs.createReadStream("src/zip/files/archive.gz");
+  const writableStream = fs.createWriteStream(
+    "src/zip/files/fileToCompress.txt"
+  );
+  const gunzip = zlib.createGunzip();
+  readableStream.pipe(gunzip).pipe(writableStream);
 };
 
-await decompress();
\ No newline at end of file
+await decompress();
diff --git a/yarn.lock b/yarn.lock
new file mode 100644
index 0000000000..fb57ccd13a
--- /dev/null
+++ b/yarn.lock
@@ -0,0 +1,4 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+