Building a 45+ microservice platform that survived acquisition and 3 agency failures

The Problem

A US wellness marketplace connecting consumers, service professionals, and facilities faced extreme business volatility. Requirements shifted constantly as the business explored different models, attracted acquisition interest, and cycled through development agencies.

The Complexity

• Three-sided marketplace: Consumers, professionals, and facilities each with different needs
• Payment distribution: Every booking required splitting payments across three beneficiaries
• Cascading configurations: Service menus inherited from organisation → facility → professional with overrides at each level
• Agency churn: Three sequential agency engagements (India, Dallas/Brazil, Boston/Colombia) introduced inconsistent code quality
• Inherited technical debt: The v2 system contained SQL injection vulnerabilities and anti-patterns

The fundamental question: how do you build a platform when you know the requirements will change dramatically and repeatedly?

Our Approach

We designed deliberately for volatility using distributed architecture patterns:

Microservice Architecture

• 45+ independent services using Dapr for service-to-service communication
• Service-owned databases: Each service manages its own MongoDB instance
• Event-driven integration: Services communicate through events, not direct calls

Key Integrations

• Stripe Connect: Three-way payment distribution handling consumer charges, professional payouts, and facility fees
• Cascading service menus: Organisation → facility → professional override logic
• Unified notifications: SendGrid and Twilio behind a single service with channel-based routing
• HubSpot: Event-driven CRM synchronization

Quality Gates

• SonarCloud CI/CD integration: Automated quality and security scanning
• 90% code coverage requirement: Enforced through pipeline gates
• Security remediation: Systematic elimination of v2 vulnerabilities

Team Coordination

Managed teams of up to 20 developers across multiple agency engagements, with a core team providing architectural consistency when agency deliverables fell short.

Outcomes

Architecture Resilience

• Platform survived acquisition, multiple strategic pivots, and three agency failures without architectural changes
• Core team could rebuild 6 months of agency work in 1 month when needed
• Flexibility validated the upfront investment in distributed design

Code Quality

• 90% code coverage achieved across the platform
• SQL injection vulnerabilities from v2 completely eliminated
• Consistent quality despite agency churn

Integration Success

• Stripe Connect handling complex three-way payment splits
• Event-driven architecture enabling rapid feature addition
• Unified notification service supporting multiple channels

Team Development

• Mentored and upskilled developers across three agency engagements
• Established patterns that enabled consistent delivery
• Core team of 3 consistently outperformed agencies of 15+

Lessons Learned

The platform was technically successful but never launched due to budget exhaustion on agency fees. The architecture proved its value; the organizational decisions around agency management did not. This experience directly informs how we advise clients on build-vs-buy and agency coordination today.