Modernising Energy Auctions through a Secure Digital Platform

Technical Approach

We built the NESO Interconnector Auction Platform on a robust, scalable architecture designed for performance, security and transparency.

Architecture Overview

The system is made up of three core layers:

1. Frontend (Web UI)

• A web based-based interface accessible via browsers.

• Allows counterparties to log in, manage users, place bids and view results.

• Optimised for clarity and simplicity, ensuring usability for both large and small organisations.

2. Backend Services

• Built using PHP 8.1, with MySQL as the relational database and Redis for in-memory caching, high-speed data access, and as a pub/sub provider to allow real-time delivery of notifications.

• Handles user authentication, bid management, auction scheduling, and integration with NESO’s spreadsheet-based workflows.

• Implements business logic for bid expiry, multi-trade splitting, and role-based access control.

3. Notifications & Messaging

• Sendgrid powers reliable email delivery.

• Twilio handles SMS alerts and two-factor authentication.

• Webhook system enables counterparties to receive real-time updates directly into their own infrastructure.

User roles and permissions

The platform is structured to reflect the different responsibilities of NESO and its counterparties. Each role has clear access rights, ensuring security without adding friction.

This role-based structure gives counterparties control over their own organisations, while NESO retains oversight and administration of the entire system.

Auction Workflow

• Browser-based access: Traders log in to view lots, place bids, and confirm results.

• API integration: Counterparties connect directly via their own systems, using webhooks and API endpoints to process data and submit bids automatically.

This dual approach ensures every counterparty can interact with the platform in the way that best suits their systems and workflows, without sacrificing transparency or consistency.

Flexible Integration Options

• Submitting bids: Counterparties can push structured bid data directly into the system, replacing manual email submissions.

• Retrieving auctions: Organisations can query active or historic auctions, including lot details and requirements.

• Managing results: Counterparties can fetch auction outcomes and confirm receipt directly via the API.

• Bid history: Access to current and historic bids for audit and compliance purposes.

• Webhooks & events: Organisations can subscribe to system events (e.g. auction creation, results available) and trigger actions in their own platforms instantly.

Security and reliability underpin the API:

• Authentication via renewable API keys issued per organisation.

• Non-repudiation using JSON Web Tokens (JWT) on all requests and responses.

• Rate limiting to prevent overload and ensure fairness across counterparties.

• IP whitelisting available for additional access control.

For counterparties, the API transforms the process from manual email workflows into a fully integrated, automated exchange. It reduces admin, accelerates decision-making and ensures that bid data is secure, verifiable and traceable end to end.

Security and Compliance

• Mandatory two-factor authentication for all user accounts.

• TLS 1.3 encryption across all communications.

• Comprehensive logging with data forwarded to a secure remote server.

This layered approach ensures flexibility, security and resilience, while providing counterparties with the tools they need to interact in the way that best suits their business.