1) Talk Title

The Hidden Complexity of Time: Lessons from a Failed Migration

2) Abstract (2–4 sentences)

Migrations often stall due to “minor” data discrepancies that explode into major production incidents. This session analyzes a real-world case where a failed time synchronization caused 50 years of data drift, threatening user trust and reporting accuracy. We will move beyond code fixes and explore how to use architectural patterns—like Anti-Corruption Layers and Contract Testing—to guarantee data integrity, reducing the risk of modernization efforts for the entire organization.

3) Description / Detailed Outline

The Business Problem: When “Time” Breaks Trust Time isn’t just a technical variable; it’s the backbone of scheduling, reporting, and compliance. When a legacy monolith and a new microservice disagree on “what time it is,” the result isn’t just a bug—it’s broken business logic and lost user confidence. This talk explores the high cost of implicit assumptions during system modernization.

Case Study: The Cost of Misaligned Systems I will walk through a specific migration scenario involving a user-centric Legacy System and a machine-centric Microservice.

  • The Incident: How a simple unit mismatch (Seconds vs. Milliseconds) silently corrupted historical data, showing events as happening in 1970.
  • The Operational Drag: How “naive” fixes (string slicing) stripped timezone context, requiring expensive manual data patches and eroding team velocity.

Architectural Solutions: Investing in Stability We will focus on engineering patterns that protect business value and ensure predictable delivery:

  • Contracts as Assets: shifting from fragile primitive types (long) to strongly-typed standards (ISO-8601) to eliminate ambiguity between teams.
  • Protecting the Core Domain: Implementing Anti-Corruption Layers (ACL) to isolate the new system from legacy debt, allowing the new team to move fast without breaking existing functionality.
  • Automating Quality Assurance: Using Consumer-Driven Contract Testing to catch integration errors in the CI/CD pipeline, preventing expensive rollbacks and ensuring “sleep-well” deployments.

Demos/Examples:

  • A “Before/After” comparison of an API contract, highlighting the shift from ambiguity to strict definition.
  • A Contract Test tailored to catch data regressions before they reach production.

4) Target Audience

Level: Intermediate Role: Backend Developers, Software Architects, Engineering Managers, and Technical Product Owners. Prerequisites: Familiarity with system integration challenges.

5) Learning Outcomes / Takeaways

  1. Reduce Migration Risk: Learn to implement Anti-Corruption Layers that let you modernize systems without risking business data integrity.
  2. Accelerate Delivery: Discover how Contract Testing automates the detection of integration bugs, replacing slow manual QA cycles with instant feedback.
  3. Standardize Communication: Gain a strategy for defining strict API contracts that align legacy and new teams, eliminating friction and rework.
  4. Preserve Business Context: innovative techniques to ensure timezone and user-intent data survive the transition to microservices.

6) Relevance (Why TDC?)

TDC attracts professionals looking for real-world solutions to enterprise challenges. As organizations invest heavily in breaking down monoliths, the ability to do so without disrupting the business is a key competitive advantage. This talk provides a blueprint for turning a high-risk migration task—handling time—into a reliable, managed process that stakeholders can trust.