Develop a simple application for working with a user database.

Budget: 200 EUR Deadline: 10 days

Hello! I understand the task.

This is a simple system for uploading and processing user lists with deduplication and segmentation logic for mailings. The main value here is the correct handling of large volumes of data and the guaranteed exclusion of resending to the same user_id.

Essentially, this is a lightweight internal tool (mini-CRM/segmenter), where the key part is a stable database, fast data operations, and clear user status logic.

It can be implemented as a web application with a simple admin panel and an optimized database, so the system works smoothly even with hundreds of thousands of records.

I suggest we discuss the details!

Budget: 2000 EUR Deadline: 7 days

Hello, I have been working on a user management system for an e-commerce platform with over 750,000 records, where I implemented automatic duplicate removal and segmentation by statuses. Experience with large databases and query optimization will help create a fast solution for your mailing!

I am curious to know - are you planning to integrate with a specific mailing platform, or do you need a universal data export?

I suggest we get in touch; I will provide you with free technical consultation and we can create a development plan + I will tell you about my team!

Budget: 199 EUR Deadline: 5 days

Hello! I am implementing a project in Java + PostgreSQL. The application will work on both Windows and Linux. If an embedded database is needed, it can be implemented as well.

Budget: 200 EUR Deadline: 3 days

Hello. I have experience in developing similar mini websites. I will do it in php+mysql. Contact me, I will do it quickly and efficiently according to the technical specifications.

Budget: 500 EUR Deadline: 15 days

Hello! I am interested in your offer: — Develop a simple application for working with a user database! I have over 15 years of experience in web application development.

Budget: 50 EUR Deadline: 2 days

Good day, Yuri!
I understood the task. A contact database manager with protection against duplicate mailings.
I will use Python + SQLite. The database can easily handle 500k+ records, a file with 100k lines is imported in 3-5 seconds. Searching by user_id is instantaneous due to indexing. Three tabs as per the technical specifications, everything is clickable without unnecessary buttons.
The PROCESSED status will be made irreversible at the database level, not just in the interface. Duplicates are automatically filtered out during import, a person will not be able to accidentally send to one user twice.

Regarding the timeline: a working version with all the main functionality in 1-2 days. On the 2nd-3rd day, testing and corrections based on your comments. In total, 2-3 days until the application is ready.

Before starting, I will clarify two points: the format of your text file and in what form the export is needed for the mailing application.
I am ready to complete the work. Please reach out!

Budget: 4000 EUR Deadline: 20 days

Hello!

My name is Alex, and I represent the NC-1 development team. For over five years, we have been building high-performance websites, mobile applications, ERP/CRM systems, and other e-commerce solutions.

I have reviewed your technical requirements for the user database management application. Given the database volume (500,000+ records) and the need for efficient deduplication, I recommend the following team and tech stack for this project:

Recommended Tech Stack:
Mobile/Frontend Developer: Flutter (Dart) — This is the most cost-effective choice, providing high performance and a smooth UI. We will use SQLite for local caching and efficient data handling.

Backend Developer: Python (FastAPI) or Node.js (NestJS). To handle 500k+ users, we will implement PostgreSQL with optimized indexing and UPSERT logic for instant deduplication.
QA Engineer: API testing via Postman, and stress testing the database to ensure stability under heavy data loads.

UI/UX Designer: Figma (clean, intuitive interfaces for status management and seamless file imports).

Project Manager: Jira/Trello, Slack, and Notion for transparent documentation and sprint control.

Preliminary Cost Estimate:
Based on the scope of work (import logic, duplicate protection, status workflows, and high-volume data management), the estimated cost is as follows:

Total Project Cost: $4000

What is included:

Architecture & DB Design: Optimized schema for fast searching and sorting.

Backend Development: Core logic for importing, deduplication, and status transitions.

Frontend/UI: Three-section dashboard with server-side pagination for large lists.

Quality Assurance: Rigorous testing of the "no-duplicate" rule and data integrity.

Deployment: Setting up the environment and launching the application.

We are ready to discuss the details and start development immediately. Would you be available for a brief call to go over the technical nuances?

Best regards,
Alex, NC-1 Team Expand

Budget: 110 EUR Deadline: 3 days

Good day. Should this be a web application or desktop/mobile? I can implement it in Python or PHP. I have experience working with large amounts of data with hundreds of thousands of records or more.

Budget: 220 EUR Deadline: 10 days

Good day. I can implement it as a desktop application in Python + PyQt6 or DearPyGui or PyQt6-WebEngine. You can look at similar projects in my portfolio.

Budget: 600 EUR Deadline: 5 days

Hello
My name is Dmitry
I have reviewed the technical specifications - the task is clear, I can implement such an application focusing on speed and stability with a large user base
How I see the implementation
- backend + database (PostgreSQL or SQLite/MySQL depending on the load)
- fast import of txt/csv lists
- protection against duplicates at the database and logic level
- status system (NEW / IN_CAMPAIGN / PROCESSED)
- search, sorting, filtering
- simple and fast interface for working with the database For 500,000+ users, I will create proper indexing and structure so that the application does not "lag" during import and search
I will also implement:
- updating the last appearance date
- protection against user_id re-entry into the mailing list
- convenient movement of users between statuses
I can create either a web application or a local system - depending on what is more convenient for you to work with
I am ready to discuss the details and suggest the optimal stack for your task 👍 Expand

Budget: 100 EUR Deadline: 2 days

I can do it in PHP, there will be a web interface, just need a domain and hosting.

Budget: 650 EUR Deadline: 7 days

Hello. I am ready to implement on Next.js/Nest.js. Please contact me.

Budget: 100 EUR Deadline: 5 days

Good day! For 500k+ records, I will perform the upload through streams and UPSERT queries into the database (SQLite or Postgres) — this is the only way to process such volumes without memory crashes. I will use UNIQUE indexes at the database level to ensure that duplicate protection works reliably, and searching by ID will be instantaneous. I will implement a clear status logic on Node.js, so that the user physically cannot enter the mailing list again. It will be a lightweight and fast utility, tailored specifically to your tasks.

Budget: 40 EUR Deadline: 1 day

Hello! I am ready to develop a reliable and fast tool for working with a user database for you. Since the database is expected to have over 500,000 records, I will implement the project in Python using either SQLite or PostgreSQL, where I will ensure proper indexing for instant searching and sorting by dates. The import logic will include automatic duplicate checking: the system will independently identify new users or update the last appearance date of existing ones, with only those who were not previously in the system receiving the status of NEW. I will create a lightweight and concise web interface with three sections, where you will be able to conveniently manage statuses and create lists for mailings, while the architecture will include protection against the same ID re-entering a campaign. The application will be optimized for high-speed performance and can easily be packaged in Docker for quick deployment on any of your servers if needed. I am ready to discuss the details and start development today.

Budget: 50 EUR Deadline: 7 days

Hello. I will do it for you as needed in Python and PostgreSQL database.

Budget: 70 EUR Deadline: 3 days

Good day, I will complete it turnkey in a few days, we can discuss the details.

Budget: 600 EUR Deadline: 10 days

It is clear that the task is to develop an application for working with a user database, including uploading lists, managing statuses, and preventing duplicates. The complexity of the project lies in the need for efficient handling of a large database (up to 500,000 users) and managing the dynamics of changes.

I propose to solve the task using a modern technology stack, which will ensure the reliable operation of the application and an intuitive interface. PostgreSQL or MySQL would be optimal for the database, and React or Vue.js can be used for the interface. This will ensure performance and ease of use. The system will include list import, user status updates, as well as protection against adding duplicates.

Risks related to performance with large volumes of data should be considered. Query optimization and indexing may be required to minimize processing time. The programming part needs to be monitored to prevent errors with duplicates during data processing.

It is important to clarify in what format the user lists will be provided (text files, CSV, etc.), and what specific user status decoding functions you envision for this application?

I can provide the project for 27,000 UAH with a completion time of 10 days. We would be happy to discuss the details and plan the next steps.

Budget: 60 EUR Deadline: 1 day

Good day.
I can implement both a desktop application and a web application.
The database depends on the choice of platform.
I will do it within a few hours.
I can start right now.