Practical work of SQL.

C# / .NET WPF Developer – Completion of Migration of a Large Invoicing Program RAFSOFT.NET Sp. z o.o. is looking for a C# / .NET developer to complete the rewriting of a large, long-standing invoicing program to a new technology. The project involves the migration of an extensive desktop application for companies, used for invoicing, handling sales documents, contractors, records, and accounting-tax functions. The new version of the program is being created in C# / .NET, using DevExpress components. The project is already about 70% rewritten. We are looking for someone who can help bring it to completion, organize the missing elements, perform tests, and ensure the new version operates in accordance with the existing program. Scope of Work: completion of the migration of a large desktop application to C# / .NET, recreation of the functionality of the old program in the new version, maintaining as identical logic of operation, appearance, and handling as possible, working with DevExpress components, analyzing existing code and comparing the operation of the old and new versions of the program, fixing bugs, completing missing functions, and testing the application, collaborating on the final preparation of the program for deployment. Requirements: very good knowledge of C# and .NET, experience in creating desktop applications for Windows, knowledge of WPF or WinForms, experience with DevExpress or similar UI component libraries, ability to analyze a large existing project, accuracy and patience in reproducing existing functionality, ability to test one's own changes, very good ability to use AI tools supporting programming, code analysis, refactoring, and testing. Preferred: experience with legacy projects, knowledge of or previous work with Visual Basic 6.0, experience in migrating applications from older technologies to C# / .NET, knowledge of issues related to invoicing, accounting, JPK, or KSeF, experience working with large business applications. Who We Are Looking For: We are looking for a self-sufficient, precise, and technically experienced person who can enter an existing project, understand its logic, and consistently bring it to completion. In this project, it is very important not only to write new code but also to faithfully reproduce the operation of the old program — both in terms of functionality and appearance as well as handling. We also require proficiency in using AI tools in daily programming work. We are looking for someone who can use AI practically: for code analysis, bug finding, speeding up migration, creating tests, and organizing the project. About the Company: RAFSOFT.NET Sp. z o.o. is a Polish company creating software for entrepreneurs, accounting offices, and small and medium-sized enterprises. Our main product is the VAT Invoice program, supporting the daily handling of invoices, sales documents, contractors, records, and settlements in accordance with Polish regulations. We develop our own desktop applications and tools related to invoicing, accounting, KSeF, JPK, and automation of business processes. Our solutions are designed with stability, ease of use, and practical application in users' daily work in mind. Company website: www.rafsoft.net

It is necessary to calculate statistics in a medical project (including correlations). Additionally, there is a request to create a mathematical model for predicting the development of pathologies based on available data.

Hello, I need your help in implementing a task. Fix the bugs on the website page, the page displays a 404 error.

Project Meta Implement Viber integration without using third-party CRM systems. All work with messages should be done directly in our internal CRM based on BAS / 1C 8.3.Current System BAS / 1C 8.3 Custom configuration "Customer Service" Database of over 40,000 subscribersRequired Implementation Integration through an official Viber Business provider (TurboSMS, GMS Worldwide, or another agreed service). The button "Write to Viber" in the subscriber card. Sending messages directly from BAS. Receiving incoming messages via Webhook. Automatic linking of messages to the subscriber by phone number. Complete preservation of correspondence history in the subscriber card. Displaying the time, message status, and the manager who responded. Simultaneous work of multiple managers. Message templates for quick responses. Assistance with setting up the Viber provider, API keys, and Webhook. Transfer of all source code and settings after the work is completed.Acceptance Conditions The work is considered completed after successful testing of all functions on the working database and transfer of the source code.Guarantee 1 month warranty for fixing bugs related to the implemented functionality. Further modifications are carried out by separate agreement.Result After the project is completed, managers should be able to fully work with Viber directly in BAS: write to clients, receive responses, view correspondence history, and communicate without using third-party CRMs. All source code, modifications, API keys, and settings will be transferred to the client after the project is completed.

Looking for an experienced developer (or a small team) to create an MVP mobile application — a service for urgent calls to specialists similar to Uber, Uklon. Development needed: • mobile application for iOS and Android (Flutter); • server part (REST API); • admin panel; • database. Main functionality of the MVP: registration of clients and performers; authorization; map and geolocation; order creation; search for the nearest performer; push notifications; in-app chat; ratings and reviews; order history; admin panel. Requirements: experience in developing marketplaces, delivery services, taxi or similar projects; Flutter; Backend (Node.js / Laravel / Go / NestJS — ready to discuss); PostgreSQL; understanding of scalable architecture. In your response, please include: Links to applications in the App Store and Google Play. Similar projects you have developed. What architecture you propose. Approximate cost of the MVP. Development timeline. Important: looking for a specialist for long-term cooperation. Interested in the quality of architecture and the possibility of further scaling the project. Budget is negotiable with the suitable candidate.