Working Notes
Raw insights from inside real systems
Real-world learnings from building and operating lending and debt collection platforms. Documenting what works, what breaks, and why.
Systems In Practice
A collection of working notes and system thinking drawn from building and operating lending, debt collection, and fintech systems. Focused on practical learnings, design tradeoffs, and failure modes that only show up in production.
Three Pillars
Not every moment calls for the same kind of insight. Sometimes you need observation, sometimes structure, sometimes proof of what works.
System Thinking Library
Patterns that repeat across financial systems
Frameworks and mental models for understanding complex financial systems. Pattern recognition across workflows, data flows, and integration architectures.
Practitioner Knowledge Base
Practical guidance that holds up in use
Technical deep dives for operators. Code patterns, deployment strategies, monitoring approaches, and troubleshooting guides from the trenches.
Featured Topics
Writing
Dec 22, 2024 Observability Strategies for Production Systems
Logging, metrics, and tracing that actually help when things break. Building observability into debt-collections or fintech systems from day one.
Writing
Dec 18, 2024 Collections Account Inbound Schema: JSON Schema + OpenSearch Query Patterns
A debt-collections view of the inbound account record. How to validate consistently with JSON Schema, then index in OpenSearch for fast worklists, segmentation, and exception handling.
Writing
Dec 12, 2024 Event-Driven Architecture Patterns
Mental models for building event-driven systems. Understanding event sourcing, CQRS, eventual consistency, and when to use them in fintech contexts.
Latest Topics
View all topics → Writing
Dec 22, 2024 Observability Strategies for Production Systems
Logging, metrics, and tracing that actually help when things break. Building observability into debt-collections or fintech systems from day one.
Locked Exploring
Dec 20, 2024 Loan Servicing State Machines
Modeling loan lifecycles as state machines. From origination through payoff, handling transitions, edge cases, and state-dependent business rules.
Writing
Dec 18, 2024 Collections Account Inbound Schema: JSON Schema + OpenSearch Query Patterns
A debt-collections view of the inbound account record. How to validate consistently with JSON Schema, then index in OpenSearch for fast worklists, segmentation, and exception handling.
Writing
Dec 18, 2024 Database Schema Patterns for Specialist Lending Solutions
Practical database design patterns for loan management, payment history, and account relationships. Balancing normalization with query performance.
Writing
Dec 15, 2024 Payment Processing Patterns in Lending Systems
Understanding idempotency, retry logic, and reconciliation patterns when handling payments at scale in lending platforms.
Writing
Dec 12, 2024 Event-Driven Architecture Patterns
Mental models for building event-driven systems. Understanding event sourcing, CQRS, eventual consistency, and when to use them in fintech contexts.
What We Cover
Specialist Lending Solutions
Morgages workflows, underwriting automation, loan servicing, payment processing, and portfolio management.
Debt Collection
Collections strategy, dunning workflows, payment arrangements, skip tracing, and regulatory compliance.
Workflow Automation
Event-driven architectures, state machines, task orchestration, and integration patterns.
Platform Modernisation
System design, data modeling, API patterns, scalability strategies, and operational excellence.
Want to Collaborate?
Have insights to share or interested in working on fintech systems together? Whether it's contributing content, reviewing patterns, or building tools—let's connect.
Complex systems are not solved in one sitting.
They are understood, one SiP at a time.