How IDFC FIRST Bank built a real-time customer data access engine with Aerospike

Customers decide whether their bank is reliable after the first second of opening their app. In that moment, trust is shaped not by promises or branding, but by whether the system responds correctly and immediately.

Balances must update instantly, or else a payment will appear as if it didn't go through. Product eligibility should always reflect the most current state (for example, an offer tied to maintaining a minimum balance must go away the moment that balance dips). Risk and compliance flags (such as negative balances or overdue equated monthly installments (EMIs)) need to surface immediately. And most importantly, every channel (from mobile to web, or branch to partner applications) must show the same information at the same time.

IDFC FIRST Bank launched in 2018 and has been built with a digital-first mandate from day one. Naturally, as the bank scaled, it expanded rapidly across channels, all while operating under the same regulatory and reliability expectations as far older incumbents. 

With stakes this high, even a few hundred milliseconds of stale data can trigger real consequences like duplicate payments, missed fraud detection alerts, or compliance exceptions. Real-time data access is no longer optional; instead, it is core banking infrastructure that keeps every channel accurate, consistent, and aligned.

IDFC’s challenge: Protecting consistency across every channel as the bank scaled

As IDFC gained more customers, "digital-first" exploded from just a mobile app into an ecosystem of touchpoints. It now spans mobile and web applications, relationship managers on tablets, contact center systems, partner applications, non-banking financial company (NBFC) integrations, kiosks, onboarding workflows, conversational banking interfaces, and a growing set of internal microservices.

Here’s where scaling introduced a subtle yet dangerous problem. As more systems came online, the architecture evolved to include local copies, caches, and channel-specific data stores in order to stay fast. Each system worked in isolation, but together, they introduced failures that were difficult to detect and harder to recover from. Minor delays would snowball into inconsistent customer views; systems would make decisions based on outdated information; writes would occur in different places with no single authoritative source of truth; and multi-channel architectures would drift out of sync completely. 

For a regulated bank, those inconsistencies are far from cosmetic. After all, every channel is making real-time decisions about balances, eligibility, risk, and compliance. When customer state is even briefly out of sync, the impact shows up immediately in customer trust and operational risk, making the bank’s ability to scale digital channels safely impossible.

Traditional relational databases hit natural limits at IDFC’s scale

Although IDFC FIRST Bank was founded less than a decade ago, its early systems were built on the same core foundations trusted across the banking industry, including relational databases like Oracle. These systems are adept at what they were designed to do: enforcing strong transactional guarantees, maintaining integrity across structured data, and supporting core financial records. 

But as IDFC's digital footprint expanded, the shape of the workload changed. Modern digital banking increasingly relies on high-concurrency access patterns, in which a single customer interaction can kickstart a cascade of real-time reads and updates (e.g., balance checks, eligibility rules, risk flags, and partner validations) that happen simultaneously across an array of channels. Those interactions need to be completed in tight millisecond windows, consistently, even as traffic spikes.

Relational databases were simply not built to act as a shared, real-time customer-state layer for this kind of fan-out. They're not optimized for serving millisecond-level reads simultaneously across many channels, nor for keeping customer state continuously synchronized across cloud and on-prem environments as scale increases.

As IDFC grew, these constraints became structural rather than incremental. The bank’s real-time access needs had simply outgrown what a traditional relational database management system (RDBMS) is designed to handle efficiently.

IDFC built a unified real-time customer state store that keeps every channel aligned

Given its challenges around keeping every channel consistent at scale, IDFC FIRST Bank needed a single place where customer state could be read and updated in real time with no latency spikes, stale data, or operational fragility.

This would allow every channel to read the same customer truth, and every update to propagate immediately. The system also had to hold up under high concurrency, hybrid deployments, and continuous disaster recovery (DR) testing.

This unified, real-time customer state store, powered by Aerospike, now sits at the heart of IDFC’s digital architecture. Aerospike serves as the bank’s real-time customer access engine, ensuring that, regardless of where a request originates, every channel reads the latest customer state rather than operating on stale or inconsistent data.

Delivering that consistency at scale required predictable low latency without relying on fragile caching strategies. Aerospike allows IDFC to serve real-time reads and writes directly from the system of record, avoiding separate cache layers that introduce warm-up delays during failovers or DR tests. As a result, performance remains predictable even during disruptions.

Under the hood, this is enabled by Aerospike’s Hybrid Memory Architecture (HMA). Indexes live in RAM for fast lookups, while records are stored on SSD. It’s a deliberate split that delivers near in-memory latency at NVMe economics. It also supports high-throughput, low-latency access without the cost and operational burden of keeping full datasets in memory. Fine-grained bins and sets further enable high concurrency across many microservices that are accessing the same customer state.

The architecture also supports IDFC’s hybrid operating model. Not all workloads can run entirely on the cloud or on bare metal. Aerospike’s Cross Datacenter Replication (XDR) synchronizes customer state across environments with sub-millisecond latency, ensuring consistent reads and writes, regardless of deployment location. Self-healing replication automatically restores target replication factors after failures, so DR and business continuity tests no longer require manual intervention.

At scale, access patterns matter as much as raw performance. Aerospike’s shared-nothing design uses partition-aware, single-hop access, routing each request directly to the node that owns the data. This helps IDFC avoid hotspots and keep tail latency tightly bounded, even when interactions fan out into dozens of checks. The bank can also maintain stable p99 performance as workloads shift between onboarding spikes, risk evaluations, and partner traffic. And when capacity is needed, the cluster scales horizontally by adding nodes, with rebalancing happening in the background, while foreground latency remains steady.

These capabilities, together, replaced fragmented customer views with a single, coherent real-time state, keeping every channel aligned even as IDFC continues to scale its digital operations.

With a real-time customer state store, IDFC unlocked new reliability and new digital experiences

Once IDFC FIRST Bank consolidated customer state into a single, real-time access layer with the help of Aerospike, the impact showed up immediately in how the bank operated, and more importantly, how customers experienced its digital channels.

Performance and resilience

From a systems perspective, gains were instantaneous: read and write performance improved by 75% to 90%, giving IDFC the headroom to support digital growth without needing to invest heavily in additional infrastructure. Replication latency also dropped 66%, allowing cloud and on-prem environments to work together with significantly reduced consistency risk. Compared with alternative solutions, the platform delivered approximately 20% higher efficiency, driven by better throughput per unit of compute.

Reliability improved as well. Uptime increased by “another nine,” reflecting a full order-of-magnitude gain in availability. DR and business continuity drills now pass consistently without last-minute interventions from the team, which strengthens confidence across engineering departments, internal audit, and regulators.

From firefighting to forward motion

With customer data consistently available and synchronized across environments, DR and failover exercises became routine rather than disruptive. Engineers no longer had to chase down inconsistencies between systems or compensate for replication lag during peak periods.

That stability changed the day-to-day focus of the organization significantly. Instead of firefighting data misalignment, teams could concentrate on building new digital capabilities, refining onboarding and servicing flows, and extending the platform to support additional channels and partners.

A consistent experience that customers and partners can trust

All of this ultimately surfaced where it matters most: in the customer and partner experience. With the unified real-time state store in place, IDFC achieved:

• 75% to 90% improvement in read/write performance

• 66% reduction in replication latency across hybrid environments

• ~20% higher efficiency compared to alternative solutions

• Real-time data consistency across all channels, including mobile, web, branch, and partner applications

Now balances, risk flags, and eligibility are updated instantly for both IDFC customers and internal teams. Every system, including partner applications, works from the same current data, so onboarding, servicing, and product journeys move fast, without relying on best guesses or stale snapshots.

Even across a hybrid cloud and on-prem environment, customer experiences remain consistent and predictable. The complexity stays hidden behind the scenes. Customers may never see the architecture behind IDFC FIRST Bank, but they feel it every time a balance updates instantly, an offer makes sense, or an account state is exactly right.