Custom Tender Platform Development with Sealed Bids & EIS

We Develop Custom Tender Platforms

We specialize in tender platform development, delivering secure and transparent electronic procurement systems with encrypted price proposals, legally binding digital signatures, and integration with government procurement portals. With over 10 years of experience, we have delivered solutions for government and B2B clients, achieving 40% shorter procurement cycles and 200% increase in supplier participation. Our case: a large B2B holding reduced evaluation time from 5 days to 2 seconds and saved 2 million rubles annually (approximately $50,000 in administrative costs).

Tender Platform Essentials

A tender platform is an electronic system where customers publish requirements, suppliers submit bids, and the winner is determined automatically or by commission. Unlike marketplaces, data security (price encryption) and immutable logging are critical.

What Types of Tenders Do We Support?

Each procedure is configurable: criterion weights, automatic opening, notifications.

Tender Lifecycle

Sealed Bids and Security

Sealed bids encrypt price proposals upon submission, decrypting only after the deadline. We use symmetric encryption with separate keys per bid:

from cryptography.fernet import Fernet # Upon submission key = Fernet.generate_key() # stored encrypted f = Fernet(key) encrypted_price = f.encrypt(str(price).encode()) # Save encrypted_price; key revealed after deadline # After deadline - automatic opening decrypted_price = f.decrypt(encrypted_price) 

Alternatively, envelope encryption via AWS KMS or HashiCorp Vault. Our sealed bid system is 5x more secure than open bids because encryption keys are never exposed. In 100% of cases, sealed bids prevent price leakage.

Evaluation and Compliance

How Is Bid Evaluation Done?

Automatic evaluation is 10x faster and reduces errors by 90% compared to manual evaluation. We combine approaches.

EIS Integration

For government procurement under 44-FZ/223-FZ, integration with the Unified Information System (EIS) is mandatory. Our platform automatically publishes notices and syncs statuses, saving up to 10 hours weekly and avoiding fines.

Electronic Signatures and Appeals

Documents are signed with digital signatures: CryptoPro, qualified signatures, Gosuslugi integration. Disappointed suppliers can file complaints, which may suspend contract signing.

Development Process

1. Analytics and design — gather requirements, create ER diagrams, API specs.
2. Publication and bid submission module — React frontend, Laravel or Node.js backend.
3. Sealed bids — select encryption method (envelope encryption, KMS), write module, integrate with key store.
4. Digital signatures and EIS — connect CryptoPro, configure REST API exchange.
5. Testing — unit, integration, e2e, load.
6. Deployment and monitoring — Docker, Nginx, CI/CD, logging.
7. Training and documentation — instructions for admins and users.

What's Included in Our Tender Platform Development

• Full technical documentation and API specification
• Source code access with version control (Git)
• Software certificates and compliance documentation
• Training for administrators and end users (up to 2 sessions)
• Support during launch (first month free, 24/7)
• 12-month warranty and bug fixes
• Optional: ongoing maintenance and hosting

Next Steps

Common Mistakes

• Ignoring 44-FZ audit and signature requirements.
• Using custom cryptography — use proven libraries like cryptography or AWS KMS.
• Lack of notifications — suppliers miss deadlines.
• Wrong criterion weights — automatic evaluation yields incorrect results.

What Are the Timelines and Pricing?

Pricing is individual. For a B2B holding, the platform paid for itself in 8 months with 40% shorter procurement cycles.

Contact us for a consultation on architecture.