Applicative Maintenance for a Mobile EventBooking Platform

Taking over a live marketplace app from a previous vendor migrating cloud infrastructure, remediating critical technical debt, and establishing 24/7 managed services with enterprise-grade SLAs.

100%

Uptime SLA

60%

Bundle Size Reduction

<2H

P0 Time-to-Restore

8W

Week Seamless Handover

We take our clients’ confidentiality seriously. While we’ve changed their names and certain identifying details, the results are real.

CLIENT PROFILE

Sector

Cross-Industry

Timeline

6+8 weeks

Region

Europe

Engagement Type

Managed Services

Executive Summary

A European entertainment booking startup operating a cross-platform marketplace for live event performers needed to transition their entire application stack from a previous development partner. The platform, built with Flutter for mobile, VueJS for web, Node.js APIs, and MongoDB, was running in production across AWS and Azure with significant technical debt accumulated over multiple development cycles.

Redex Consulting was engaged to execute a complete application handover comprising two parallel workstreams: first, a comprehensive architecture audit and refactoring initiative to address critical security vulnerabilities, performance bottlenecks, and outdated dependencies; second, a cloud migration and managed services engagement to establish 24/7 operational continuity with enterprise-grade SLAs.

The engagement demonstrates Redex’s ability to take over complex, live applications from other vendors stabilizing operations, modernizing the stack, and delivering ongoing managed services that let the client focus on growth rather than firefighting.

The Challenge

The application had accumulated significant technical debt under the previous vendor, creating security risks, performance issues, and operational fragility.

Forked Dependencies

Critical libraries, including the Stripe payment integration, were forked to personal developer repositories instead of using official packages, creating supply chain risks and making updates impossible.

Severe Performance Issues

The web application loaded 19+ MB of assets on initial page load (12.46 MB canvaskit.wasm + 7 MB main.dart.js), causing unacceptable load times and poor user experience on mobile networks.

Outdated Framework

Flutter was stuck at version 3.7.5 (multiple major versions behind) exposing the app to known security vulnerabilities and preventing access to critical performance improvements.

No Crash Monitoring

Firebase Crashlytics was configured but not actively monitored. The team had no visibility into production crashes, error rates, or user-impacting issues until customers reported them.

Split Cloud Infrastructure

Production ran on AWS while staging was on Azure creating operational complexity, inconsistent environments, and higher costs from managing 2 separate cloud providers.

No CI/CD Pipeline

Deployments were manual and error-prone with no automated build, test, or deployment pipeline. This slowed release cycles and increased the risk of human error in production.

Our Approach

Workstream 1

Architecture Audit & Refactoring

We structured the engagement into 2 parallel workstreams: one focused on modernizing the application, the other on establishing operational continuity.

Architecture Audit & Refactoring

A 6-week intensive program to address the most critical technical debt, modernize the stack, and establish proper engineering practices, all while keeping the live production application running without disruption.

Architecture Improvement & Refactoring

2 weeks

Replaced all forked libraries with official pub.dev packages, removed the Canvaskit renderer in favor of HTML renderer, restructured code architecture, and activated crash logging.

CI/CD Pipeline Setup

2 weeks

Built automated build and deployment pipelines for both production and pre-production environments, eliminating manual deployment risks.

Amplitude Analytics Integration

1.5 weeks

Implemented Amplitude for comprehensive UX tracking and user journey analytics, giving the client data-driven insight into how performers and bookers use the platform.

Flutter Upgrade (3.7.5 → 3.27.1)

3 weeks

Executed a major framework upgrade spanning multiple versions, including full regression testing across all platform features: booking flows, payments, messaging, and profiles.

API Performance Optimization

2 weeks

Optimized performer listing APIs and database queries to reduce response times and eliminate bottlenecks in the marketplace search and discovery experience.

Our Approach

Workstream 2

Application Handover & Managed Services

An 8-week structured transition from the previous development partner to Redex, including cloud migration, knowledge transfer, and establishment of 24/7 managed services with defined SLAs.

Cloud Migration

Migrated all containers (staging and production) to a unified AWS organization, consolidating from a split AWS/Azure setup to simplify administration and reduce costs.

24/7 Service Management

Established round-the-clock monitoring and incident response for the production environment, ensuring the marketplace remains operational for performers and bookers across all time zones.

Technical Support

Provided office-hours technical support including bug fixing, non-critical operations (account management, log analysis), and small feature evolutions to keep the platform competitive.

Knowledge Transfer

Executed a structured learning phase where the Redex team absorbed functional expertise from the client’s management team and technical documentation from the previous vendor.

SLA Framework

Enterprise-grade service levels ensuring the marketplace stays live and responsive for performers and event organizers worldwide.

P0 – Service is down

P1 – Major feature down (payments, login, user data)

P2 – Minor bug on functioning feature

Infrastructure

Unified cloud, unified operations

Consolidating from a split AWS/Azure setup to a single cloud provider reducing operational complexity, improving deployment consistency, and cutting infrastructure costs.

Technology Stack

A cross-platform marketplace architecture spanning mobile, web, back-office, and API layers, all containerized and deployed on AWS.

Flutter + BLoC

Cross-platform framework

Dart

Programming language

Firebase

Crashlytics, Analytics, Messaging

VueJS v2 + VueX

Marketing website

Bootstrap-Vue

UI component library

VueJS + Webpack

Back-office admin panel

Node.js + TypeScript

API server

Loopback 4

REST framework

MongoDB

Primary database

AWS EC2

Compute instances

CloudFront + S3

CDN & static storage

Docker + Nginx

Containerization & routing

Stripe

Payment processing

Zendesk

Customer messaging

Google APIs

Geocoding & location

CI/CD Pipelines

Automated deployments

Amplitude

User analytics & UX tracking

Firebase Crashlytics

Error monitoring

Production Architecture

The production environment runs on AWS with 4 EC2 instances behind a load balancer, CloudFront CDN, and S3 static storage, all containerized with Docker.

CloudFront

Global content delivery

S3 Bucket

Static assets & media

Load Balancer

Traffic distribution

Nginx

Reverse proxy + API

MongoDB

Primary database

AWS Storage

File & media storage

Website & Backoffice

VueJS

WebApp

Flutter

API Server

Node.js

Operations

Always-on, always watching

Our managed services team monitors the platform 24/7 ensuring performers can accept bookings, organizers can browse and pay, and the marketplace stays live across every time zone.

Value Delivered

Measurable improvements across performance, security, operations, and developer experience transforming a fragile application into a stable, well-managed platform.

60%+ bundle size reduction

Removed Canvaskit renderer, implemented lazy loading

Faster API responses

Optimized performer listing queries and database indexes

Modern Flutter (3.27.1)

Access to latest performance optimizations and features

Zero forked dependencies

All libraries migrated to official packages

Active crash monitoring

Real-time visibility into production errors

Stripe payment secured

Updated to latest official Stripe SDK

99.9% uptime SLA

24/7 managed services with defined incident response

P0: 2hr time-to-restore

Critical incidents resolved within SLA commitments

Unified cloud (AWS)

Simplified administration, consistent environments

Automated CI/CD

Push-to-deploy for both staging and production

Amplitude analytics

Data-driven UX insights and user journey tracking

Structured support model

Ticket-based support with clear SLAs and escalation

07.

Our Perspective

Taking over a live application from another vendor is one of the most challenging engagements in consulting. It requires not just technical skill, but the discipline to audit honestly, prioritize ruthlessly, and transition smoothly without disrupting the business.

This engagement reinforced several principles we apply to every managed services engagement and a few lessons that were specific to marketplace platforms.

01

Audit Before You Operate

Never assume the previous vendor’s documentation is accurate. Our initial audit uncovered critical issues (forked libraries, missing monitoring, split cloud environments) that would have caused incidents if we’d simply taken over operations without investigating first.

02

Secure the Supply Chain First

Dependencies forked to personal repositories are a ticking time bomb. If a developer changes their GitHub username or deletes their account, your production build breaks. Migrating to official packages was our first priority even before performance work.

03

Parallel Workstreams, Not Sequential

By running the architecture refactoring and managed services handover in parallel, we compressed what could have been a 4-month transition into 8 weeks. The key was clear ownership boundaries between the 2 workstreams.

04

SLAs Build Trust

Defining clear P0/P1/P2 response times with measurable TTA and TTR commitments gave the client confidence from day one. They knew exactly what to expect and we had the operational framework to deliver consistently.

05

Managed Services Is Not Just Monitoring

Applicative maintenance means continuous improvement. Our ticket-based support model includes small evolutions and bug fixes, ensuring the platform keeps improving even in maintenance mode.

08.

Engagement Team

A lean, cross-functional team combining project management, DevOps expertise, mobile development, and 24/7 operations, structured to execute the handover efficiently while maintaining production stability.

Project Manager / Tech Lead

Migration & Handover Coordination

DevOps Engineers

Cloud Migration & CI/CD

Flutter Developer

Framework Upgrade & Refactoring

Backend Developer

API Optimization & Bug Fixes

QA Engineer

Regression Testing & Validation

24/7 Operations Team

Service Management & Monitoring

About the Client

A European Entertainment Booking Startup

The client operates a two-sided marketplace connecting event organizers with live performers across Europe. Their platform enables discovery, booking, secure payment, and communication available as a native mobile app (iOS & Android), a web application, and a back-office administration panel.

As the platform grew, the client needed a reliable technology partner to take over operations from their previous development team, modernize the technical stack, and provide ongoing managed services that would let them focus on scaling the business rather than managing infrastructure.

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