FullStack Labs

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Hire our Elite Node.js Developers

FullStack Labs is a leading team of Node.js developers, engineers, programmers, coders, and architects. Uber, Siemens, and hundreds of other companies have chosen us for their mission critical software development projects.

Hire Our Elite node.js Developers Now
What's included

We’ll review your code base and provide a report that includes quality scores for the following:

  • Test suite and test coverage
  • Code quality, including a CodeClimate report
  • How soon can FullStack start on my project?
  • Dependencies
  • Error and performance monitoring
  • Documentation
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Trusted By:
UberSiemensEricssonNFIBEkso BionicsCalifornia

A Few of Our Expert Node.js Developers

Daniel Coy
Daniel Coy
Senior Software Engineer
Node.js Developer
  • Location icon
    Bogota, Colombia
  • Education icon
    License in Child Pedagogy, Universitaria Minuto de Dios
  • Star icon
    Years of Experience
Leonardo Siqueira
Leonardo Siqueira
Senior Software Engineer
Node.js Developer
  • Location icon
    Blumenau, Brazil
  • Education icon
    Systems Analysis and Development, Infomatics, FTEC
  • Star icon
    Years of Experience
Ben Carle
Ben Carle
  • Location icon
    Washington, DC
  • Education icon
    Ph.D, Computer Science, University at Albany
  • Star icon
    Years of Experience
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A Few Node.js Frameworks We Love

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A minimalist framework built for performance, we prefer Express for most of our node.js apps.

koa, sails, meteor logos

Have a node app built with Koa, Meteor, Sails, or Feathers.js? We’re here to help. Our experienced team has worked with nearly all Node.js frameworks.

custom icon

No framework, no problem. Our team of expert Node.js developers is well versed in scripting, provisioning, and working with custom code.

Client Testimonials

The experience I've had with other firms is in direct contrast to what FullStack did. I'm comparing them with two other firms I worked with in the past. They care a lot about what their clients are doing. They bring their ideas and concepts to the table. I felt like they were on my team. They added a lot of value in terms of ideas and continue to do so. No matter who's working on the project you feel like they care about the work that's being produced.

- Rob Burns -
President, Bunk 1

FullStack Labs' managers have been engaged throughout. The whole project management staffing, matching team to task has been fantastic. All their staff is very committed. I'm very aware of how much bureaucracy there is in the tech world, and we've gotten nothing but solutions. I am totally happy with their approach to everything, their integrity, honesty, the whole thing. It's great.

- Executive Director -
Valley CAN

We were very happy with the way the whole process was facilitated. We started talking to FullStack Labs three months before we signed any contract with them. We met with them in person several times. We wanted to find out what their philosophy is. Both Brian and David are fathers with young children, so they understand the importance of the work we are doing. That shows through in their work. It was obvious they cared deeply.

- Anna Sadovnikova -
CEO, MomKit

How to Hire Node Developers Through FullStack Labs

  • 1. Talk to us!

    We will work with you to understand your technical needs, team dynamics, and goals.

  • 2. Meet our available talent

    We’ll send you FullStack Node developers that match your technical requirements, with links to their FullStack profile page which outlines their work experience and technical abilities, as well as their FullStack technical summary page, which includes a 60 minute video of the developer completing FullStack’s coding challenge, and a plethora of other technical information from their interview with us.

  • 3. 14 Day Risk-free trial

    Start the engagement. Work with your new Node developers for a trial period, ensuring they're the right fit.

    Check icon

Engagement Models for Node.js Projects

New Node.js Apps

We design and build greenfield apps of all shapes and sizes using Node.js combined with a React.js, Ember.js, or Angular.js javascript framework.

Existing Node.js Apps

Have a legacy Node.js app? We’re here to help. From debugging and maintenance to feature development and DevOps, we'll tailor a development plan to meet your needs.

Node.js Team Augmentation

Need to add a Node.js developer to your existing team? We'll seamlessly integrate as many Node.js developers as needed, to help you go faster and level up your team's skills.

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FullStack Labs is proudly remote.

We have an ever growing team of incredible people currently located in these countries.
Meet our Leadership Team
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Meet our Leadership Team

Our Clients Love Us, And You Will Too.

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Let's Talk!

We’d love to learn more about your project.
Engagements start at $75,000.

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Essential Technical Node.js Interview Questions

FullStack Labs is a leading team of Node.js developers, engineers, programmers, coders, and architects. Uber, Siemens, and hundreds of other companies have chosen us for their mission-critical software development projects. Node.js is a crucial tool to develop your project, here are a few Node.js Interview Questions you can use to screen your Node.js candidates:

Q: What is your favorite HTTP framework and why?


There is no right answer for this. The goal here is to understand how deeply one knows the framework she/he uses. Tell what are the pros and cons of picking that framework.

Q: What is callback hell and how can it be avoided?


Callback hell is when you have many deeply nested callback functions.

This is callback hell:

    	    getMoreData(a, function(b){
        	        getMoreData(b, function(c){ 
                        getMoreData(c, function(d){ 
                            getMoreData(d, function(e){ 


To avoid: modularization: break callbacks into independent functions

  • use a control flow library, like async
  • use generators with Promises
  • use async/await
Q: What is the output of the following code snippet? explain what will happen line-by-line.


const objectArray = [ 
  { id: 8, body: 'cat', value: 12},
  { id: 4, body: 'dog', value: 24 }

const result = objectArray
  .filter( obj => !!obj )
  .reduce( ( accumulator, obj ) => accumulator + obj.value, [])

console.log(result - 10)

  • The result variable will filter out the items in the objectArray that are undefined then build a new array using reduce which will not add the numbers together but will concatenate the numbers together.
  • The console.log will print the value "1214"
Q: What are the ways to overcome single threaded nature of Node.JS?


While NodeJS's main thread is a single thread there are a lot of things "under the hood" that are not single threaded and allow NodeJs to run operations in parallel.

child_process and cluster modules can be used to get around single threads but can be expensive in performance.

The worker_threads module can be used to execute JS in parallel and can share memory unlike child_process and cluster. worker_threads are experimental as of NodeJS v12.4.0

Q: List Pros and Cons of Node.JS clusters?



- Efficient use of processing power: As a cluster deploys on each core of a processor, you will basically have lighter node apps using each core of the CPU and not waste any power.

- Load balancing: Cluster libraries manage the load efficiently sending every second call to the next instance of the app on a different core of processor.

- Simple implementation: Cluster libraries are simple to use and setup. Very less to none extra coding is required, deployment/node scripts can be enough.

- Solution to single-threaded nature: As NodeJs started is single threaded in nature, you can not use all the CPU power if the app/process is only using one core of your multicore CPU. Cluster lets you use all cores.


- Session based apps can not utilize a NodeJs cluster effectively as sessions will have to be set up on each instance.

- Using clusters on Cron jobs can be problematic if parallel processes target the same records at the same time.

Q: Why is Buffer considered a Super Data Type?


- Buffer is NodeJS Datatype.  It is a NodeJS addition to five primitives (boolean, string, number, undefined and null) and all-encompassing objects (arrays and functions are also objects) in front-end JavaScript.

- Buffer looks like an array of integers where each entity represents a byte of data. Overall, it represents a fixed-size chunk of memory (can't be resized after creation) allocated outside of the V8 JavaScript engine.

- Buffer can be created from an array, another buffer, ArrayBuffer or a string. It also supports encoding options as well such as UTF-8, ASCII, HEX and others.

- Think of buffers as extremely efficient data stores. In fact, Node.js tries to use buffers any time it can, such as when reading from a file system and when receiving packets over the network.

- In the age of streaming, it is a highly used datatype for packet data transfers.

Q: What is the difference between __dirname and process.cwd?


  • __dirname: returns the directory of the executed/called file 
  • process.cwd(): returns the root directory of the project


  • Project
    - main.js
  • Module
    - moduleFile.js


-- CODE language-bash keep-markup --
console.log(process.cwd()) -> ./project
console.log(__dirname) -> ./project


-- CODE language-bash keep-markup --
console.log(process.cwd()) -> ./project
console.log(__dirname) -> ./project/Module

Q: What module should be used if we want to read a file?


NodeJs has a built-in function called readFile, that function is into the module fs

Q: What is the role of REPL in node.js?


It is used to execute ad-hoc Javascript statements. The REPL shell allows entry to javascript directly into a shell prompt and evaluates the results. For the purpose of testing, debugging, or experimenting, REPL is very critical

Q: Is node.js a single or multi thread process?


In essence, it is a single thread process, it does not expose child threads and thread management methods to the developer. Technically, Node.js does spawn child threads for certain tasks such as asynchronous I/O, but these run behind the scenes and do not execute any application JavaScript code, nor block the main event loop.

Q: What command instructs the node package manager to install a package named my-package and register it as a development dependency?


-- CODE language-bash keep-markup --
npm install my-package --save-dev

Q: Consider the following middleware function signature:


-- CODE language-javascript keep-markup --
function myMiddleware(x, y, z) 

What is the purpose of the third argument, z?


The third argument will be the next middleware function in the application’s request-response cycle. This argument is more commonly named next.