Vladimir Shalimov

Diool is a payment platform for businesses operating in Cameroon. It provides payment services to merchants and service suppliers.

The Diool Android app is used by point-of-sale operators (cashiers) to collect cash or mobile money payments from their customers. It is also used by business owners/managers to do other business operations (sending invoices, transferring money, etc).

Features:
• Various payment transactions: regular merchant payments, mobile money recharges, and invoice cash settlements
• User's financial account management, balance top-up/withdraw, and transaction history with export options
• Organization management: points-of-sale and employee configuration
• Contact list to send or request payments
• Payment requests (invoices)
• Approval flows for some types of operations
• Feature customization based on business/user type or pricing plan

My Contributions:
• I managed the Android-related development—from requirements and UI analysis to Google Play publication. Starting from an existing project, a complete architectural and UI redesign was eventually done, and numerous features were implemented. We've published dozens of releases with the team and continue the project's active development.

Imagine massive events like rock concerts or music festivals with thousands of visitors. Typically there are multiple sale points inside: cafes, bars, souvenir shops, etc. Every visitor has an electronic wristband that can be used to pay at these points, and Billfold is a system to operate such payments.

Billfold software consists of a back end, a web panel, and a batch of Android apps.

Features:
• Check-in board (used for wristband activation)
• Two-sided shop app (one side for the salespeople, the other for the customers)
• Top-up app (used to refill wristband balance)
• Multiple payment types
• Event customization
• Extremely quick service: from seven seconds per customer
• Thousands of orders during a short concert intermission
• Partial offline work
• And more

My Contributions:
I received the project with an existing codebase and was responsible for the entire Android development in the system. I refactored some modules to improve stability and resolve a set of user-annoying issues and also added dozens of new modules and features. I then repeatedly reviewed and redesigned business requirements to extend system capabilities and simplify behavior. Later, I also mentored a second Android developer and did code reviews.

A cargo taxi application with excellent, practical service. The Android part contains two applications: the customer and driver apps.

Features:
• Order a ride and choose a cargo type, route, departure time, and other advanced options.
• Track ride status.
• Track car geolocation.
• Change the route during the ride (if possible).
• Provide the option to pay by bank card.
• Driver/customer ratings/feedback
• User profile along with a ride history
• Templates for repeated rides
• Driver statistics
• Discount promo codes

My Contributions:
I developed both Android applications from scratch to production-ready based on requirements and UI design provided by the client.

We developed this graphics engine as a library for our client, a forex software development company, to use in their own products.

Engine features:
• Rendering: Forex candles (rates history), the current rate;
• Rendering: trading volumes, indicators, and trader's orders;
• Animated scrolling, gestures, horizontal scaling, and vertical scaling (auto and manual);
• The ability for users to add and edit custom graphic elements (lines, text labels, various chart marks);
• The ability for a client developer to customize all aspects rendered: colors, fonts, size, layout, scale/scroll modes, and custom graphic elements;
• Cross-platform compatibility with the iOS version;
• Nice performance.

My contributions:
I was a technical lead for a team of 3-4 Android developers. I designed engine architecture and organized the teamwork, including task management and assignment, estimates and planning, code review, and result control. I also communicated with the client team directly, which involved requirements analysis and technical consultations. I also wrote the code for the most challenging modules.

An application for emergency medical workers (paramedics) to collect various information about incidents in the field: location, patient's claims, injury characteristics, diagnosis results, medical procedures performed, and so on. When workers arrive back at the hospital, the collected information gets transferred to the hospital server and stored for future use.

Features:
• A massive set of various types of information to collect;
• Various information types: from primitive strings and numbers to videos and car accident diagrams;
• All the fields that are to be filled by a medical worker are server configurable as various medical departments may use completely different kinds of information;
• Offline mode: in field;
• Online mode: in hospital;
• Skins;
• Reports;
• Driver license barcode scanner;
• Miscellaneous.

My contributions:
I led a team of 3 – 6 developers, and my challenge was organizing the quick parallel development based on a previously developed iOS version. I oversaw the architecture design, task planning, and code reviews, along with teaching and mentoring team members. I also wrote the code for the application core and a few modules.

MaybeCoffee is a startup that launched a dating app. The key idea was to meet a partner (similar to other dating apps) and invite them to drink a cup of coffee at once. Two applications were developed: one for regular users and one for coffee shops to integrate the system (salesperson app).

Features (regular user application):
• User profile, description, photos, and so on
• Partners search: via a list or on a map
• Mini-chats on a map
• Chat with a partner with the option of planning a coffee meeting (coffeeshop selection, order, payment) inside the chat
• Order history along with order status tracking
• Loyalty program

Features (salesperson app):
• New coffee shop order notification
• Orders list
• Order status and payment tracking and loyalty program tracking

My Contributions:
I developed the salesperson version of the app from scratch and mentored my younger colleague, who developed the regular user version app from scratch. I guided him in the architecture design and task planning along with reviewing his code to make sure it was high quality.

A nice and lightweight flower delivery application: aggregator service for various flower shops.

Features:
• Shops and goods catalog
• Cart
• Order checkout
• Bank card payment
• Orders and payments history

My Contributions:
I developed the app from scratch based on the UI design provided.

A home finances management app with an excellent UI.

Features:
• Budget tracking: income, expenses, accounts, and transactions
• Various monthly, weekly, biweekly, and annual budgets
• UI animations, draggable panels, and coins with authentic material
• Design concept from before was nearly everywhere
• Colorful daily, weekly, and monthly statistics
• Financial goals

CoinKeeper is a friendly application from 2011-2013. After we finished the first few versions, our client redesigned the application and continued the development of a new, slightly different version.

The classic version was loved by users so, the client had decided to leave it available on the market, and it is still alive!

My Contributions:
I developed the Android version, initially alone and later in a team, and created the business logic layer. The Xamarin framework was used to share business logic between the iOS and Android versions. I also contributed to the back-end development.