Leonard Ekenekiso

How I Engineer Systems

Principles for building systems that must stay correct when things go wrong.

Financial correctness, idempotency, auditability, failure isolation, observability, explicit domain boundaries, evidence-grounded AI, compatibility and tests around the invariants that matter.

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Design for failure

Retries, idempotency, fault isolation, explicit failure states and recovery paths belong in the design, not in incident patches.

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Protect financial invariants

Money movement deserves clear ownership, auditability, transactional boundaries and tests around the things that must never drift.

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Make operations observable

Structured logs, metrics, alerts and traceable state transitions make systems operable under pressure.

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AI reasons; deterministic services decide

Use AI for interpretation and reasoning, while keeping permissions, invariants and irreversible actions behind explicit deterministic controls.