Integration with the payment system stripe via API.
After payment confirmation:
- funds are credited to the user's balance;
- a transaction of type deposit is created.
Processing webhooks.
Protection against duplicate payments.

3. Automatic withdrawal of funds

The user submits a withdrawal request.
The minimum amount is a system parameter.
Statuses:
- pending
- approved
- rejected
- paid
At the time of the request, the amount is blocked.
Complete log of status changes.

4. Reservation and payment for domains / websites (with commission)

When reserving a lot:
- the buyer's funds change to reserved status;
- the reservation lasts for N minutes (configurable).
After agreement confirmation:
- the full amount is deducted from the buyer's account;
- the system commission is automatically withheld from the seller;
- the seller is credited the amount minus the commission;
- the commission is credited to the system account of the platform.
If the agreement is canceled:
- the reservation is automatically returned to the buyer.
All actions are recorded as transactions.

5. System commission

The commission is withheld only from the seller.
Types of commission:
- percentage of the transaction amount (for example, 5%);
- fixed amount (optional).
Settings:
- global commission in the admin panel;
- ability to change without code rework.
Commission:
- is displayed to the seller before agreement confirmation;
- is stored separately in transactions (system_fee).
It is prohibited to complete the transaction if:
- the seller has an incorrect balance;
- there was an error in calculating the commission.

6. Account history (user)

Types of operations:
- deposit
- withdrawal
- reserve
- release
- sale_income
- system_fee
For each operation:
- date/time
- type
- amount
- status
- related lot
Filtering by period and type.

7. Statistics for the administrator

Total system balance.
Separately:
- user funds;
- reserved funds;
- funds for withdrawal;
- platform income (commissions).
Analytics:
- commissions for the period;
- top sellers;
- exchange turnover.
View any user's account.
Export data to CSV.

8. Technical requirements

Backend: Java Spring Boot.
ACID transactions.
All amounts — BigDecimal.
Audit log of all financial operations.
Protection against race conditions.
Tests for:
- deduction;
- reservation;
- commission;
- rollback on errors.

Proposals 8 Rejected 5 Discussions 1

Vitalii Shaforostov

9 1

Projects 9
Rating -
Rating 1 194

Budget: 10000 UAH Deadline: 20 days

Hello. I am ready to implement a payment module for your service using Java Spring Boot. I have experience working with payment systems. Write to me, and we will discuss everything in more detail.

Good day!

I am ready to implement a financial module for your exchange on Java Spring Boot, ensuring ACID transactions, protection against race conditions, and auditing of all operations. I have experience working with payment system APIs and implementing complex financial logic, including reservation, withdrawal of funds, and commission calculation.

Write to me in private messages, and we will clarify the details.

Maksim Dzyuba

36 0

Budget: 10000 UAH Deadline: 3 days

Good day, I can implement such a module for you. I have extensive experience working with Java Spring Boot. Due to my workload, I can offer collaboration starting from February 25. I hope for cooperation!

Yevhenii Ishchenko

0 0

Projects -
Rating -
Rating 326

Budget: 9999 UAH Deadline: 5 days

Hello! I specialize in Java Spring Boot. I am implementing a financial module with ACID, BigDecimal, and protection against race conditions. I will set up the Stripe API, commission logic, and reservation. I guarantee the security and accuracy of transactions.

The list does not show proposals concealed by the client or freelancer with a Plus profile, as well as proposals violating rules

Andrey K.

1 298 1

Budget: 27000 UAH Deadline: 15 days

Hello. I have been working with Node.js for over 8+ years. I am ready to implement the backend on Nest.js.

Dmytro Zmenkov

1 1

Projects -
Rating -
Rating 97

Budget: 10000 UAH Deadline: 2 days

Good day. I am ready to complete this project as I have extensive experience in application development.

The list does not show proposals concealed by the client or freelancer with a Plus profile, as well as proposals violating rules

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Mirgorod, Ukraine
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Financial module of the exchange

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Financial module of the exchange

5.0

Pavlo Ogurtsov

Technical task: financial module of the exchange with system commission

1. User accounts

2. Automatic account replenishment

3. Automatic withdrawal of funds

4. Reservation and payment for domains / websites (with commission)

5. System commission

6. Account history (user)

7. Statistics for the administrator

8. Technical requirements

Vitalii Shaforostov

Nick Osipov

Maksim Dzyuba

Yevhenii Ishchenko

Proposals are currently absent

Andrey K.

Dmytro Zmenkov

Current freelance projects in the category Java

Comprehensive redesign, SEO optimization, and migration of the NGO "Another Woman" website from Tilda to a modern CMS.

Real-Time Trainer