Competitive advantage for startups

We've worked with dozens of clients over the years, form one person startups to large brands and we know secret sauce to success. A small organized team, perfect for nurturing your business needs.

Here are is the proof:

  • Series A round of funding.
  • Series B round of funding.
  • Investments of $800,000.00+ several times
  • Featured on Techcrunch several times
  • https://techcrunch.com/2017/10/24/startup-o-school-raises-800000-to-improve-sex-education/

We value transparency, good communication, and quality. We use technology that would serve the goal, but in general, it's Ruby on Rails, NodeJS and front-end (React.JS, React Native, Vue.js ...)

We are partners, not just a vendor. Contact us and see the difference. 

 
$10,000+
 
$25 - $49 / hr
 
10 - 49
 Founded
2011
Show all +
Novi Sad, Serbia
headquarters
  • Bulevar Oslobodjenja 11
    Novi Sad 21000
    Serbia

Portfolio

Key clients: 

We've worked with dozens of clients over the years, form one person startups to large brands. A few of our clients are oSchool, Wrap.co, Astrology.com and many more. Discover more of our work on our portfolio https://kolosek.com/portfolio

Pulse Image

Pulse

Education technology product that helps K12 schools combine data, communications and task management into a holistic student support system .

Technology: ReactJS and Ruby on Rails

Gambit Image

Gambit

Online Turn-Based Strategy Games

Play your favorite classic multiplayer games on the web or on your mobile device

Technology: ReactJS and NodeJS

Listium Image

Listium

All your lists in one place - Create private lists, share lists with friends, or publish your lists and share them with the world. All in one place.

Technology: ReactJS and NodeJS

Rency - CryptoCurrency monitor Image

Rency - CryptoCurrency monitor

Rency provides comprehensive ratings and analysis on popular cryptocurrencies in the industry. Analyze, compare, and contrast on Rency before investing.

Built with ReactJS on front-end and Ruby on Rails on API side.

Reviews

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Backend Development for Retail Company

"The ease within which we were able to communicate was impressive."

Quality: 
5.0
Schedule: 
4.5
Cost: 
4.5
Willing to refer: 
5.0
The Project
 
Less than $10,000
 
Dec. 2019 - Jan. 2020
Project summary: 

Kolosek was hired to fix bugs in the client's backend. They utilized Ruby on Rails and Spree Commerce to redevelop their e-commerce platform. 

The Reviewer
 
1-10 Employees
 
Singapore
Mazen Kurdy
CEO, Stylemyle
 
Verified
The Review
Feedback summary: 

The team at Kolosek prioritizes tasks to deliver results in a timely manner without disrupting the client's business. They're skilled communicators and address concerns quickly. 

The client submitted this review online.

BACKGROUND

Please describe your company and your position there.

We are an online marketplace for contemporary luxury fashion. We partner with amazing boutiques in the most fashionable cities and sell their products to consumers around the world. I am the CEO and founder.

OPPORTUNITY / CHALLENGE

For what projects/services did your company hire Kolosek?

Over a period of several months some new developers turned out to be cutting corners and we realized that some aspects of their coding was sloppy... in turn it was causing some unexpected surprises... We contacted Kolasek to help us fix this issues and reinstate the proper coding procedures so that all of our previous developer work was robust and able to handle the incoming business without issue...

What were your goals for this project?

We needed someone reliable to go back through the code structure, find the weaknesses and fix them in a thorough manner so that we did not encounter issues later on in the process. That would require us even more work at a later stage...

SOLUTION

How did you select this vendor?

Upon speaking with several firms, this vendor was recommended to us. They took the time to understand our needs, look through our issues and come up with a plan to help us get back on track. They were very detailed oriented.

Describe the project and the services they provided in detail.

We were built using ruby on rails and spree commerce. We required someone to go through the last several months of our code and correct several structures that were not completed as per the required. As can be imagined, various issues arose that required additional time to rectify. For example, our payment gateway was not

What was the team composition?

The project team consisted of a developer and a manager. We spent considerable time explaining both our business model and the key requirements we need to have accomplished. Our timing was limited, hence we needed someone that could provide us results efficiently so that our ongoing business we not affected.

RESULTS & FEEDBACK

Can you share any information that demonstrates the impact that this project has had on your business?

Our solution was effectuated in a timely manner and we were able to have this accomplished with minimal effect on our ongoing business. We were able to have business continuity while we were "fixing" serious issues on our back end. Key tasks were prioritized so that secondary tasks were accomplished at a later time providing a smooth workflow...

How was project management arranged and how effective was it?

We provided all of our requirements with the project manager at Kolosek... we had in depth discussions to understand the business and our back end requirements. In turn, we wrote in depths tickets to better clarify our requirements in writing to the developers. This resulted in tasks being completed in a timely manner and helped us continue our operations...

What did you find most impressive about this company?

The ease within which we were able to communicate was impressive. Companies are always in a hurry and having someone that you can communicate with practically immediately is a great first impression rather than having to go through several people before your concerns are addressed.

Are there any areas for improvement?

Frankly, we found little to improve on. As usual, companies would always like for developers to work faster. This depends on several factors and what is actually possible. We have been pleased with the relationship.

5.0
Overall Score Kolosek was a pleasure to deal with. They are trustworthy and work to truly accomplish your needs.
  • 4.5 Scheduling
    ON TIME / DEADLINES
    Kolosek is very detailed oriented.. This is a positive that gets everyone in line with the goal of providing you with great results.
  • 4.5 Cost
    Value / within estimates
    Kolosek is very cost effective in relation to dealing with other firms we have reached out to.
  • 5.0 Quality
    Service & deliverables
    Everything was provided in a solid manner with no need to revisit any work accomplished.
  • 5.0 NPS
    Willing to refer
    I would refer Kolosek without hesitation.

Mobile & Web App Dev for HR Startup

"I'm impressed by their level of competence and flexibility."

Quality: 
5.0
Schedule: 
5.0
Cost: 
5.0
Willing to refer: 
5.0
The Project
 
$50,000 to $199,999
 
Apr. 2016 - Ongoing
Project summary: 

Kolosek developed web, iOS, and Android apps. They handled architecture, UI/UX design, development, and testing needs. Their services are ongoing.

The Reviewer
 
1-10 Employees
 
Copenhagen, Denmark
Jens Nikolaj Aertebjerg
CEO & Founder, AppPraise
 
Verified
The Review
Feedback summary: 

The apps exceeded every expectation and impressed users. Kolosek's creative ideas and meticulous planning shine during challenging times. The team sets themselves apart with their friendly attitude, deep knowledge base, and responsive communication style. 

The client submitted this review online.

BACKGROUND

Please describe your company and your position there.

I'm the CEO and founder of an HR startup. The scope of our project is substantial, stemming from years of market research on hypotheses, business models, and service delivery approaches. 

OPPORTUNITY / CHALLENGE

For what projects/services did your company hire Kolosek?

We hired Kolosek for platform strategy, architecture, development specifications, systems setup, UI/UX design, front- and backend development, and testing assistance.

What were your goals for this project?

We wanted iOS and Android mobile apps, as well as a full web app, for our market launch.

SOLUTION

How did you select this vendor?

After defining and prioritizing a set of 15 parameters, we conducted interviews with five vendors in three countries.

Our key criteria included the ability to understand the nature of our business, quickly grasp the user scenarios and requirements, and deliver an integrated solution spanning architecture, requirements, design, and development. We needed a vendor who could propose new, better ways of implementing our desired functionalities.

We didn't want to feel like just another development project; we wanted to know that our vendor invested in the project and took ownership of the concept. Kolosek outranked the other vendors by far.

Describe the project in detail.

After selecting Kolosek, we held a series of workshops and knowledge transfer sessions. We quickly decided on a scrum structure and interaction model. Although we had a full development outline, we planned all these steps, constantly re-evaluated the best sequence of deliveries, and made sure the project and team succeeded early.

The project took many twists and turns as we discovered better ways of implementing its features. Throughout these change requests and scope alterations, we felt a greater level of interaction and responsibility from Kolosek. They often suggested better scope and development plans. 

What was the team composition?

A three-person team established the basic elements. Upon seeing their high level of competence and excellent output, we quickly scaled the team up to 10 people. This team handles web and mobile development, design, architecture, and project management.

RESULTS & FEEDBACK

Can you share any outcomes from the project that demonstrate progress or success?

While waiting to launch the service in a broad market, we've conducted soft launches and targeted tests with selected clients. The project is a great success, and every app has surpassed our wildest dreams. The apps Kolosek developed are simply amazing!

How effective was the workflow between your team and theirs?

The workflow is seamless. All of our interactions, not just the easy times, are perfect. When technology is making life hell, Kolosek and their CEO step up and ensure smooth sailing.

What did you find most impressive about this company?

I'm impressed by their level of competence and flexibility, their interactive approach, and their willingness to take responsibility. They understand our users, their needs, and our requirements. 

Are there any areas for improvement?

No, but we learn a lot from them. 

5.0
Overall Score
  • 5.0 Scheduling
    ON TIME / DEADLINES
  • 5.0 Cost
    Value / within estimates
  • 5.0 Quality
    Service & deliverables
  • 5.0 NPS
    Willing to refer

Custom Web App Dev for IT Service Provider

"Kolosek has met every expectation so far. We’re extremely happy with our collaboration."

Quality: 
5.0
Schedule: 
5.0
Cost: 
5.0
Willing to refer: 
5.0
The Project
 
$10,000 to $49,999
 
June 2017 - Ongoing
Project summary: 

Kolosek built a custom web application in Ruby on Rails to capture billable calls for an IT service provider. The solution records the data in custom Linux-run servers. The team now provides support services. 

The Reviewer
 
1-10 Employees
 
Des Moines, Iowa
Igor Dobrosavljević
Founder & CEO, Grand Consulting
 
Verified
The Review
Feedback summary: 

The application allows for closer tracking of phone calls and billable client hours. The Kolosek team manages a smooth and productive workflow by providing real-time progress updates and quick responses to inquiries. Their diligence and high-quality work come at excellent value.

The client submitted this review online.

BACKGROUND

Please describe your company and your position there.

I am the founder and CEO of Grand Consulting. We provide outsourced IT services to small-to-medium-sized businesses.

OPPORTUNITY / CHALLENGE

For what projects/services did your company hire Kolosek?

We engaged Kolosek to build a custom web application that would capture our incoming and outgoing calls.

What were your goals for this project?

We needed a solution to better manage our call times and more easily bill clients for our time.

SOLUTION

How did you select this vendor?

We received a recommendation from one of Kolosek’s previous clients who was happy with their work. 

Describe the project and the services they provided in detail.

Kolosek built a call recording service in Ruby on Rails using DevOps methodology. They then connected the system to our servers, which run on custom Linux installations.

What was the team composition?

We worked with several developers overseen by a team lead. They built our MVP. Now, we have one developer who will provide support services for the next two years.

RESULTS & FEEDBACK

Can you share any information that demonstrates the impact that this project has had on your business?

The app is now a core part of our business. We now have a more straightforward process for billing our clients for phone services.

How was project management arranged and how effective was it?

Kolosek uses Pivotal Tracker to stay on top of development requests. We can see progress in real time and communicate without a hitch.

What did you find most impressive about this company?

The CEO responds quickly to every inquiry at any time of day. He gives a high level of support and is very much invested in our success.

Are there any areas for improvement?

I really can't think of any.

5.0
Overall Score We look forward to a long partnership with them.
  • 5.0 Scheduling
    ON TIME / DEADLINES
    Their team is highly responsive and flexible when it comes to scheduling future work.
  • 5.0 Cost
    Value / within estimates
    They deliver high-quality work at an unbeatable value.
  • 5.0 Quality
    Service & deliverables
    Kolosek has met every expectation so far. We’re extremely happy with our collaboration.
  • 5.0 NPS
    Willing to refer
    I’ve referred them to several vendors and clients and will definitely continue to do so.