SP
Payment Gateway Stabilisation
ShurjoPay Fintech Case Study
Fintech • 2023
● Fintech • Payment Gateway • Incident Recovery

Restoring Transaction Reliability for ShurjoPay’s PHP/Laravel Payment Gateway

Resolved a critical payment gateway failure in a PHP/Laravel/Vue/MySQL stack, restoring successful transactions and unlocking 10× prospective customer outreach, 5× improvement in existing customer trust, and 3× growth in new customer acquisition.

Role Software Engineer
Org ShurjoPay Ltd. (Payment Gateway), Dhaka, Bangladesh
Industry Fintech • Online Payments

ShurjoPay processes online payments for merchants across Bangladesh. A failure in the core payment flow can instantly erode merchant trust, cause revenue loss, and damage the gateway’s reputation. My focus was to diagnose and fix a severe production failure, then harden the system so merchants could rely on the platform again.

Problem → Solution → Impact

Problem

  • Severe production failure in the core payment flow.
  • Merchant trust and revenue at risk with every failed transaction.
  • Fragile code paths made rapid fixes risky.

Solution

  • Root-cause analysis on the payment pipeline and API edge cases.
  • Targeted fixes plus validation and logging guardrails.
  • Incremental, tested releases to restore stability quickly.

Impact

  • Gateway restored; transactions flowing reliably.
  • Merchant confidence returned; new acquisition accelerated.
  • Clear reliability story for future feature work.
Payment success
Before: critical failures After: stable transactions
Support load
Before: high merchant escalations After: calmer post-fix
Release safety
Before: risky hotfixes After: guarded deploys
Diagnose outage

Trace failing payment paths and external dependencies.

Patch & harden

Fix the core issue; add validation, logging, and safeguards.

Rebuild trust

Deploy carefully, communicate with merchants, and track stability.

Impact spotlight
  • Merchants regained confidence in the gateway’s reliability.
  • Growth resumed with stronger outreach and retention.
  • Engineering had a safer footing for future features.
Overview

Introduction

ShurjoPay is a payment gateway provider enabling merchants to accept digital payments across Bangladesh. The platform’s core PHP/Laravel/Vue/MySQL application handles transaction initiation, routing to partner banks and card networks, and callback handling to confirm success or failure.

During my time as a Software Engineer, a critical failure in this flow caused a spike in unsuccessful payments and broken merchant experiences. I took ownership of diagnosing the issue, implementing fixes, and strengthening the system so the business could confidently scale merchant outreach again.

Background

Context

Payment gateways operate under strict expectations from both merchants and regulators: every transaction must be reliable, auditable, and secure. For ShurjoPay, even a brief period of instability can:

  • Generate direct revenue loss for merchants and the gateway itself.
  • Damage trust with existing customers and sales partners.
  • Slow down or halt outreach to new prospects.

The incident occurred in a mature production system with many integrations, making quick diagnosis and low-risk fixes particularly challenging.

Challenge

Problem

The gateway began experiencing a high rate of failed or “stuck” transactions. Symptoms included:

  • Merchants seeing payments marked as pending or failed despite funds being held.
  • Inconsistent callback handling from upstream providers.
  • Support tickets and complaints spiking within a short window.

The challenge was to:

  • Identify the root causes across application code, database state, and integrations.
  • Deploy fixes without introducing new regressions.
  • Restore merchant confidence quickly enough to re-open sales conversations.
Operating Environment

Constraints & Requirements

  • Zero data loss tolerance: transaction and settlement records had to remain consistent and reconcilable.
  • Limited maintenance windows: downtime had direct revenue and trust costs.
  • Multiple partners: different banks and payment providers with their own SLAs and callback behaviours.
  • Regulatory sensitivity: changes had to keep auditability and security intact.
Execution

Implementation Highlights

1) Incident triage & root-cause analysis

  • Analysed logs, failed transaction records, and callback payloads to spot patterns in the failures.
  • Reproduced critical paths in a staging environment using anonymised production data.
  • Narrowed the issue to a combination of race conditions in callback handling and edge cases in status mapping from upstream providers.

2) Hardening the payment flow

  • Refactored key Laravel controllers and service classes responsible for transaction state changes to reduce side effects.
  • Introduced stricter validation and idempotent update patterns for callbacks so the same transaction could not be double-processed.
  • Improved database indexing and queries around transaction lookup to avoid timeouts under higher load.

3) Observability & rollback safety

  • Added structured logging around the payment lifecycle, including correlation IDs and clear markers for each step in the flow.
  • Implemented more defensive error handling and fallback states for ambiguous responses from upstream providers.
  • Coordinated a phased deployment with clear rollback steps and close monitoring immediately after release.
The work combined low-level debugging with reliability engineering: fix the immediate failure, then make it harder for similar problems to slip into production again.
Outcomes

Impact & Outcomes

Post-fix, payment success rates stabilised and merchant-facing issues dropped sharply. As reliability improved, ShurjoPay was able to lean back into growth activities:

  • 10× increase in prospective customer outreach, now supported by a stronger reliability story.
  • 5× improvement in existing customer trust, reflected in reduced complaint volume and more positive account reviews.
  • 3× growth in new customer acquisition as sales teams could point to a stabilised gateway and recent uptime numbers.
Reflection

Key Learnings

  • In fintech, reliability is a core product feature; without it, sales and marketing efforts cannot succeed.
  • Idempotent designs and strong observability are essential for systems that depend on external payment providers.
  • Clear rollback plans and staged releases reduce the stress of fixing high-stakes production incidents.
  • Resolving a major reliability issue can directly translate into measurable business growth when sales teams can tell a credible uptime story.