How Qualifast Helped Build
the Colibra Travel App

Android

Web App

Backend

Cloud

From Startup POC
to Hundreds of Thousands of Users

Colibra is a travel compensation startup that built a mobile application allowing passengers to receive compensation for delayed flights. Qualifast partnered with the founding team from the earliest stages of the product, helping design, build, and scale the platform.

This case study describes how the product evolved from an early startup proof of concept (POC) to a mobile application downloaded hundreds of thousands of times.

PROJECT OVERVIEW

Client: Colibra

Industry: Travel / Insurance Technology

Product: Mobile application for flight delay compensation

Startup MVP development

Mobile application development

Backend platform development

Viral referral campaign infrastructure

SEO platform development

Android (Kotlin)

iOS (Swift)

Angular web application

Java backend services

Server-side rendered SEO platform

Building a Startup Proof of Concept in a Weekend

In the early days of the project, the idea for Colibra existed but the company had not yet secured funding.

A meeting with one of the most important venture capital firms in Bulgaria was scheduled with very short notice: on Friday the founders learned that they would pitch on Monday.

To maximize the chances of success, the Colibra founders and the Qualifast team decided to build a working product demonstration over the weekend.

Within two days we developed a frontend prototype using Angular, showing the core product experience for end users.

The goal of the prototype was not to build the full system, but to allow investors to clearly understand how the product would work.

Shortly after the pitch, Colibra secured €250,000 in pre-seed investment from Eleven Ventures, one of the largest early-stage investments in Bulgaria at the time.

While many factors contribute to a successful funding round, having a working product demonstration significantly improved the clarity of the product vision.

A MAJOR
STARTUP PIVOT

Only a few weeks after securing funding, the team decided to pursue a completely different product direction.

The original idea focused on a blockchain-based network for resolving travel insurance claims The concept allowed individuals to review insurance claims and reach decisions through distributed voting.

However, the team identified a stronger opportunity based on EU flight delay compensation legislation.

The product pivoted to a mobile application allowing passengers to receive compensation for delayed flights, even for shorter delays.

The new concept had several advantages:

It targeted a large consumer market
It had strong potential for viral growth
It focused on a clear user problem: delayed flights

This pivot required a complete rebuild of the product and a deep focus on the aviation industry.

Qualifast started developing the new application from scratch.

LAUNCHING THE
MOBILE APPLICATION

Within a few months the new product was implemented and launched.

The platform consisted of:

Mobile applications

Android (Kotlin)
iOS (Swift)

Web platform

Angular web frontend for internal back-office operations

Backend

Java backend services supporting compensation calculations and data processing

The product followed slick user interface designs prepared by Colibra’s in-house design team. After launch, the application quickly gained traction.

The mobile apps were downloaded hundreds of thousands of times, with some days seeing several thousand installs.

The strong user response validated the product concept and confirmed the market demand.

ENGINEERING ARCHITECTURE &
TECHNOLOGY STACK

To support rapid product development and future scalability, the platform was built using a modern engineering stack covering backend systems, cloud infrastructure, development workflows, and monitoring tools.

Backend Architecture

The backend services were responsible for flight data processing, compensation calculations, referral tracking, and business logic.

Language & framework: Java with Spring
ORM: Hibernate
Build system: Gradle
Database: PostgreSQL

Quality & Monitoring

The platform included monitoring and quality tools to ensure reliability and maintain high code standards.

Code quality analysis: SonarCloud
Application monitoring: CloudWatch
Crash reporting: Firebase Crashlytics
Repository hosting: GitHub

Deployment & Change Management

The development workflow enabled safe deployments and reliable database migrations as the product evolved.

Version control: Git
Continuous integration: Jenkins
Database migrations: Flyway

Development Environment

The engineering team used modern development tools for mobile, backend, and infrastructure development.

IntelliJ IDEA
Claude Code
Android Studio
Xcode

Cloud Infrastructure

The system was deployed on Google Cloud infrastructure designed to support scaling as user demand increased.

Cloud platform: Google Cloud
Container orchestration: Kubernetes
Infrastructure: Load balancers and server instances
Managed database services: Cloud SQL

QUALIFAST BECOMES
AN EARLY INVESTOR

As the product grew, the Qualifast team became increasingly confident in both the product and the founding team.

Based on this belief, Qualifast decided to take an unusual step for a development partner: we invested in the startup.

Instead of traditional project payments, we agreed to work partly in exchange for equity, becoming shareholders in the business.

This was the first investment of this type made by Qualifast, demonstrating our long-term commitment to building successful startup products.

BUILDING VIRAL GROWTH WITH A
FACEBOOK CHATBOT

To accelerate user growth, the Colibra marketing team developed a referral campaign designed to create viral adoption.

Users could invite friends to try the application. Each successful referral was entered into a raffle to win a vacation to the Maldives.

To support this campaign, Qualifast built a Facebook chatbot system that allowed users to:

Track Referral Conversions
Generate Referral Links
Invite Friends

The frontend was built using server-side rendering, generating fast HTML pages optimized for search engines.

The system had to process large amounts of flight data and generate statistics for thousands of routes while maintaining very low latency.

Over time the website started attracting substantial organic traffic from search engines.

In many searches related to flight routes, the platform appeared just below major flight tracking websites, driving additional users to the mobile application.

BUILDING AN SEO FLIGHT STATISTICS PLATFORM

COVID AND THE
SECOND PRODUCT PIVOT

The COVID pandemic had a major impact on the aviation industry.

As flights were grounded worldwide, EU legislation compensating delayed flights was temporarily removed, which broke the original business model of the application.

The product pivoted again.

Colibra transformed into a travel booking application, allowing users to book flights with built-in protection against cancellations and delays.

The system used actuarial models to determine pricing and risk, effectively embedding flight insurance into the booking price.

The long-term vision expanded to include:

Flight Booking
Accommodation Booking
Travel Add-Ons And Upsells

BUILDING STARTUP PRODUCTS
WITH QUALIFAST

Qualifast partners with founders to design, build, and scale digital products.

Our team helps startups:

Build MVPs And Prototypes
Develop Mobile And Web Applications
Scale Products After Product-Market Fit
Navigate Major Product Pivots

From early proof-of-concept prototypes to platforms with hundreds of thousands of users, we help startups turn ideas into real products.

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RELEVANT FAQs

Qualifast acted as a startup technical partner, helping Colibra build early product prototypes, mobile applications, backend services, cloud infrastructure, referral campaign systems, and SEO-focused web platforms.

Colibra was a travel compensation startup that built a mobile application helping passengers receive compensation for delayed flights.

The platform included native Android development with Kotlin, native iOS development with Swift, Angular web applications, Java backend services, server-side rendered SEO pages, and Google Cloud infrastructure.

Yes. Shortly after demonstrating the early product prototype built with Qualifast, Colibra secured €250,000 in pre-seed investment from Eleven Ventures.

The mobile application reached hundreds of thousands of downloads, with some days generating several thousand installs.

Qualifast helped Colibra rebuild the product after major strategic pivots, including the shift from an insurance-claims concept to flight delay compensation and later toward travel booking during COVID.

Scaling startup MVPs with Qualifast

From initial concept to final deployment, we build high-quality digital products of all sizes by leveraging a specialized stack of industry-leading technologies. If you’re looking for this level of execution for your own project, Contact Us to discuss how we can apply our expertise to your vision using the technologies below.

How Qualifast Helped Build the Colibra Travel App

From Startup POC to Hundreds of Thousands of Users

PROJECT OVERVIEW

Building a Startup Proof of Concept in a Weekend

A MAJORSTARTUP PIVOT

LAUNCHING THE MOBILE APPLICATION

ENGINEERING ARCHITECTURE & TECHNOLOGY STACK

QUALIFAST BECOMES AN EARLY INVESTOR

BUILDING VIRAL GROWTH WITH A FACEBOOK CHATBOT