AWS User Group Cebu · Lightning Talk

Deconstruct
to Construct

Break things on purpose, so you can build things well on purpose.

Systems Thinking Reverse Engineering Architecture

Opening

We are builders

From the first hello-world to a production system, our instinct is to construct.

But when something's broken, do we really understand why? Or do we just patch the symptom and move on?

“It works on my machine” “Add a retry” “Bump the timeout” “Restart it”

The Idea

Two moves, one loop

Move 1 · Deconstruct

Take it apart

Map every component, every dependency, every assumption. See the system as it is, not as you wish it were.

Move 2 · Construct

Put it back together

Rebuild only the parts that earn their place. Everything else gets simplified, removed, or replaced.

Motivation

90%+

of a system's lifetime cost is in understanding & changing it.

Clarity is the cheapest form of scale. Deconstruction is how you find clarity.

How

A repeatable method

Map the boundaries — what are the edges of this thing?
Trace the flow — where does data actually go?
Question every part — does each piece earn its existence?
Model failure — how does each part let you down?
Recompose deliberately — rebuild only what matters.

AWS Lens

Deconstruction on AWS

Legacy monolith	→ carve functions, events, bounded contexts
Fat IAM role	→ least-privilege per action and resource
Service now	→ what breaks, and what does it cost?
Instrumentation	→ trace, observe, then cut the bloat

Case Study

A flaky API

Deconstruct: traced every call, dependency, and retry storm.
Found: unbounded retries hiding a hot partition and a 3× over-provision.
Construct: bounded retries with jitter, idempotency, scaled-down fleet.
Result: p99 latency down, cost down, and a system we finally understand.

Takeaway

You can't build it better
until you really know it.

Start small. Pick one subsystem. Take it apart on purpose. Put it back better.

Deconstruct Understand Construct Repeat

Wrap-up

Thank you.

Questions? Let's take a system apart together.

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Deconstructto Construct