Денис

Denys Maksymov
Senior Flutter Engineer & Full-Stack AI Engineer

Summary
Senior Flutter & Full-Stack Engineer with over 7 years of experience building cross-platform
applications and digital products, primarily within fintech and cryptocurrency domains.
Possesses deep expertise in Dart and Flutter, with extensive experience implementing scalable
architectures using BLoC, Provider, Clean Architecture, SOLID principles, and Domain-Driven
Design.

Over the last 2 years, I have been working as a Full-Stack Engineer, building not only mobile
applications but also web platforms, desktop software, back-end services, and deploying
production servers. I actively leverage AI tools to accelerate development, research ideas, and
deliver solutions more efficiently.

Beyond software development, I focus on validating hypotheses, building MVPs and prototypes,
and exploring new technologies across various domains. My experience includes fintech
products, data encryption and security, extended reality solutions, AI-powered systems,
real-time architectures, and other innovative areas.

I have successfully delivered products from concept to production, combining software
engineering with product thinking. My work spans architecture design, backend development,
cloud infrastructure, CI/CD, server deployment, integrations, and user experience optimization.

Passionate about creating scalable and maintainable systems, I continuously explore emerging
technologies and apply artificial intelligence not only for code generation but also for research,
product discovery, rapid prototyping, and solving complex business challenges.

Technical Skills

Programming Dart (Primary)
Languages Python (AI-assisted development)
JavaScript
 HTML5
CSS3
SQL
Bash/Shell scripting

Tools and
Technologies Flutter, Firebase, Bloc, Dio, Hive, Provider, GetX, REST, JWT, WebSocket,
GraphQL, Freezed, Isolates, SQflite, Cloud Functions, Firebase Auth,
Firestore, Firebase Storage, FCM, Custom Paint, CI/CD, Git, Clean
Architecture, Domain-Driven Design, SOLID, MVC, Unit Testing, Integration
Testing, Firebase Emulator, Firebase Remote Config, Flutter Web, Flutter
Desktop, Google Maps, Geolocator, QR Code, Camera, In-App Purchases,
Push Notifications, Secure Storage, Shared Preferences, Analytics, Sentry,
Crashlytics,

AI & LLM Technologies:
OpenAI API, Claude API, Gemini API, LLM Integration, AI Agents, Multi-Agent
Systems, MCP (Model Context Protocol), Prompt Engineering, AI-Assisted
Development, RAG (Retrieval-Augmented Generation), Vector Databases,
Embeddings, Function Calling, Structured Outputs, Context Management,
Workflow Automation, Tool Calling, Agentic Systems, AI Chatbots, Semantic
Search, Knowledge Bases, AI-powered Applications, Streaming Responses,

Backend & Infrastructure:
Python, Node.js, Linux, Ubuntu Server, Nginx, Docker, VPS Deployment,
SSH, Systemd, PM2, Reverse Proxy, SSL/TLS, Server Administration,
Webhooks, Background Services, Real-Time Systems, API Design,

Other SOLID, OOP, DRY, Clean Architecture, Component-Based
Architecture, Separation of Concerns

Job History

3 years 2 months MAKSOFT-TECHNOLOGY UA
Project Fintech Systems (NDA)

Description A comprehensive business management system that optimizes
internal processes and improves customer interaction.
Main goal:
To provide centralized monitoring of balances, transaction
management, and partner interaction, enabling a complete and
up-to-date overview of the financial status of the network of
exchange offices in real-time.

Project role Lead Developer Flutter

Tools and Flutter, Firebase, Bloc, Git, Firebase Auth, Firestore, Firebase
technologies Storage, Flutter Desktop, Secure Storage, Hive, Get

Project ■ Lead the development and implementation of a mobile app,
responsibilities desktop application, bot, and website based on Flutter and
React.
■ Design architecture at various levels, both for the overall
system and for individual programs within the system that
have different roles.
■ Coordinate the work of cross-functional teams, including
designers, website developers, bot developers, backend
developers, and QA.
■ Review code and fix bugs.
■ Mentor junior developers and conduct technical training
sessions.
■ Manage project timelines, deliverables, and resource
allocation.
■ Identify and resolve technical issues throughout the entire
development lifecycle.
■ Interact with the client, present completed stages, and
adjust features, interfaces, and solutions during system
development.

1 year N-iX

Project Mobile Fintech Project (NDA)
Description This is a banking mobile application designed to provide users with
secure and convenient access to their financial services.

Project role Senior Flutter Developer

Tools and Custom Paint, CI/CD,Unit Testing, Integration Testing, Dio, Hive,
technologies Bloc, Freezed, REST, JWT, Shared Preferences,

Project ■ Development of a banking mobile application
responsibilities ■ Participation in feature discussions of the application
■ Writing tests
■ Developing screens and individual components
■ Expanding functionality
■ Developing logical components
■ Working with localization
■ Developing animated widgets

7 months Software Development Company

Project Mobile Fintech & Crypto Project (NDA)

Description Banking application (mobile banking)
The application allows you to view accounts and balances on them.
There is a screen for a specific account, which displays the balance,
available credit, and a list of transactions. You can pay bills or
services. It is possible to transfer funds by card number or
between your own accounts. You can view the history of charges or
expenses. You can download the statement both for a specific
transaction and for the entire account

Project role Flutter Engineer

Tools and Custom Paint, SQLlite, Bloc, REST, JWT, Shared Preferences, Google
technologies Maps, Geolocator,

Project ■ Keep responsibilities consistent in one grammatical form:
responsibilities past tense, infinitive, or gerund
■ Writing visual and logical components
■ Writing a transaction tape
 ■ Writing components for displaying transaction history
■ Writing components for making payment on a loan
■ Development of the main screen with maps
■ Transfer of part of the application from Provider to Bloc
■ Create SQLite table for data caching
■ Animations
■ In case of an error during a transaction through channels,
calls the vibro method on the platform

8 months Software Development Company

Project Project for lawyers and victims (NDA)

Description In the application, users can find a lawyer by category of expertise
and invite them to take on their case. The lawyer receives a
notification and can either accept or decline the request. If
accepted, both parties gain access to a chat where they can start
discussing the case.

Project role Flutter Engineer

Tools and
GraphQL, Bloc, REST, Shared Preferences, Sockets
technologies

Project ■ Writing visual and logical components (revision and
responsibilities optimization of the chat)
■ Writing asynchronous methods
■ Customizing internal sound notifications
■ Extending and supporting the existing architecture
■ Refining and optimizing push notifications

10 months Software Development Company

Project Project for filming QURE
Description
The application allows you to post a vacancy — for example, for a director,
3D animator, or any specialist. Freelancers can search for and respond to
these vacancies. Once a freelancer shows interest, the client receives a
notification and can view the freelancer’s profile and approve the
application. After approval, the freelancer receives a job offer and can
contact the client directly.

Project role Flutter Engineer

Tools and
Bloc, REST, Shared Preferences, Get
technologies

Project ■ Writing visual and logical components
responsibilities ■ Alteration of the main screen
■ Creating a calendar widget
■ Setting up push notifications
■ Writing tests
■ Work with data caching

10 months Freelance

Project My own project

Description Program on a tablet larger than 7 inches with a connected
thermo-printer for printing receipts for the dance hall where
classes were held.

Project role Flutter Engineer

Tools and
Flutter, Firebase, Bloc, Cammera, QR-code, Hive
technologies

Project ■ Adding a manager's payment record and editing it
responsibilities ■ Adding dance groups with indication of the time and price
for services
■ Creating a customer account
■ Cash desk for accepting payments
■ After payment, each printer prints a receipt
 ■ Firebase-based database
■ Customer balances are debited on a specific day
■ Mark that the client has arrived at the lesson
■ After the checkout is closed, the administrator receives a
message in the Telegram channel with the amount and the
name of the manager who closed the checkout
■ Until the moment of collection, the manager's balance is
increased and updated after collection
■ It is possible to mark the client as sick, and then the money
for the lesson will not be debited for the period while they
were sick
■ It is possible to sort clients by groups or halls
■ There is a client search by first and last name to view or edit
information

6 months DataWiz

Project NDA

Description Sales analytics application for the domestic Ukrainian market

Project role Flutter Engineer

Tools and
Bloc, Firebase, REST, Camera, QR-code reader
technologies

Project ■ Arrangement of graphic elements
responsibilities ■ Writing asynchronous methods
■ Writing repositories
■ Setting up interaction with the backend

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