Zero
downtime during production cutover via phased parallel-run migration
Hearing Aid Technology / Healthcare
Hearzap: Full Platform Re-Engineering for Hearing Aid Technology
How we re-engineered Hearzap's legacy platform into a modular, scalable microservices architecture — delivering zero-downtime migration and unlocking product velocity for India's leading hearing care platform.
Full Platform Re-Engineering for India's Leading Hearing Care Platform
At a glance
Full-stack
microservices decomposition with legacy feature parity maintained
↑ Velocity
new feature development unblocked after re-architecture
The challenge
Constraint 01
Hearzap's legacy platform had become a bottleneck to growth — limiting new feature development, creating performance issues at scale, and generating significant engineering overhead.
Constraint 02
The business required a full re-engineering of the platform without disrupting existing customer workflows or operational continuity — a high-risk constraint given Hearzap's active clinical user base across India.
Constraint 03
Any re-architecture had to maintain complete feature parity with the legacy system during migration while simultaneously delivering net-new capabilities aligned to Hearzap's product roadmap.
The approach
Decision 01
We began with a full architecture assessment before writing a single line of new code — mapping legacy dependencies, identifying performance bottlenecks, and designing a modular system architecture aligned to Hearzap's product roadmap.
Decision 02
We executed a full-stack microservices decomposition across frontend, backend, and data layers — rebuilding in Go, React, and TypeScript with Tailwind CSS, TanStack Router, and TanStack Query, with scalability and maintainability as first-class requirements.
Decision 03
Performance engineering was embedded throughout — including load testing, production monitoring, and optimised clinical workflows — to ensure the re-engineered platform met Hearzap's reliability and latency requirements at scale.
Decision 04
We ran a phased migration with a parallel-run period, keeping legacy and new systems live simultaneously to validate parity and ensure zero-downtime production cutover — protecting Hearzap's clinical operations throughout the transition.
The outcome
Hearzap's platform was fully re-engineered from a monolithic legacy system into a scalable, modular microservices architecture — without a single moment of downtime for clinical users.
Engineering overhead from the legacy system was eliminated, and new feature development velocity was restored. The team could now ship product improvements at the pace the business required.
With scalability and maintainability now built into the platform's foundation, Hearzap is positioned to support its planned expansion to 250 stores nationwide without architectural constraints.
Zero
downtime during phased production cutover
Full parity
legacy features maintained throughout migration
↑ Velocity
product development restored post re-architecture
Tech stack used
GoReactTypeScriptTailwind CSSTanStack RouterTanStack QueryMicroservicesPostgreSQLRedisKubernetesGCP
Lessons
Legacy re-engineering succeeds when architecture assessment precedes code. A phased parallel-run migration — not a big-bang cutover — is the only reliable way to re-platform a live clinical system without operational risk.
FAQ
How do you re-engineer a live platform without disrupting operations?
We use a phased parallel-run approach — both legacy and new systems run simultaneously, with traffic shifted incrementally after parity is validated. This eliminates big-bang cutover risk entirely.
How do you ensure feature parity during a full re-architecture?
We audit and document every legacy capability before writing new code, then validate parity at each migration phase using automated testing and side-by-side comparisons before decommissioning legacy services.
Why microservices over a modernised monolith for Hearzap?
Given Hearzap's growth trajectory and multi-domain product surface — clinical workflows, e-commerce, audiologist tooling — microservices provided the modularity needed to scale and ship independently across product areas.
Re-platform without the risk
We can assess your legacy architecture and design a phased re-engineering plan that protects operational continuity while unlocking product velocity.
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