INDEXO: Ensuring a New Bank’s Competitiveness by Evaluating System Performance Through Load Testing

Overview

INDEXO is a Latvian company founded in 2017 with a focus on making improvements in the Latvian pension industry. In 2024, INDEXO expanded their services by launching its own bank, a significant step that brought with it an equally significant challenge: ensuring the new banking system could handle real-world demand from day one.

To achieve this, INDEXO partnered with TestDevLab to subject the system to load testing ahead of its public launch. TestDevLab simulated the conditions the system would face once live, following key scenarios outlined by INDEXO, to confirm it could perform reliably during periods of high volume of incoming requests.

Testing Objectives

TestDevLab focused the load tests on three key scenarios that represented the most critical user interactions the banking system would need to sustain high user load at launch:

• Authentication and Initial Data Extraction
  Performing requests to log into the system, establish a WebSocket connection and confirm that account data is retrieved successfully through this connection.
• Payment Concurrency
  Executing a burst of payments in a short period of time to confirm that all transactions get processed without notable delays.
• User Sign-Up and Onboarding
  Simulating multiple users completing the account creation and onboarding flow at the same time – a particularly important scenario given that INDEXO was preparing for a public launch and expected a surge of new sign-ups.

Test Approach

Load testing was not the only area in which INDEXO had collaborated with TestDevLab. By the time the load testing team was onboarded to deal with the appropriate challenges, INDEXO already had another established team from TestDevLab who had successfully built and implemented an automated test suite. This helped accelerate the load testing process, as the existing scripts could be repurposed as the basis for the load tests, significantly reducing scripting time and allowing the load testing team to move quickly and scale the scripts across multiple test runners.

These scripts were adapted for TestDevLab’s in-house Go-based load generation and performance testing tool. When certain challenges with the tool occurred along the way, like when WebSocket connectivity proved incompatible with the tool's existing capabilities, the fact that the tool was developed and maintained internally meant our engineers could resolve the issue rapidly, without dependency on a third-party vendor, and ensure it aligned with the project’s needs.

Using this performance testing tool, tests were executed iteratively, slowly increasing the RPS (requests per second) value each time until performance degradations became visible. TestDevLab tracked and reported on:

• Request error rates, including the exact response code and timestamp of each error
• Response times for each endpoint triggered by the test

Other data was also extracted from these tests, however, the extraction was managed by INDEXO themselves. By synthesizing this data alongside INDEXO's own monitoring, both teams were able to make well-informed judgments on whether the system’s ability to handle load was satisfactory.

Value Delivered

Through this testing project, INDEXO gained a thorough assessment of their banking system's performance, visibility into functional errors uncovered as a side effect of load testing, and concrete insights to guide future optimizations.

The collaboration didn't end at launch. When INDEXO later migrated to a new infrastructure, TestDevLab was brought back in to run the same load testing scenarios and confirm that the migration hadn't introduced any performance degradation, giving INDEXO continued confidence in their system's reliability.