Delivery vs Maintainability
Fast in the cheap places, careful in the expensive ones.
4 to work through
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beginner Multiple choice
A team has three weeks to launch and has agreed that exactly one corner will be cut. Four candidates are on the table. Which shortcut is the safe one to take?
3 min answer -
intermediate
A quick-commerce grocery operator running dark stores needs substitution handling for out-of-stock items. Option A is a rule table inside the existing order service: three weeks and it will need rework. Option B is a separate availability-and-substitution service with its own store: eleven weeks. The business does 45000 orders a day, cancels about 6% of them for stock reasons, expects the feature to recover roughly a third of those, and earns about 1.10 dollars of contribution per order. Roughly what is the cost of delay, and what rework budget does it justify?
3 min answer -
intermediate
A team must ship a major capability quickly and the design that ships fastest is not the one that is easiest to maintain. How should the trade-off be made?
1 min answer -
advanced
How would you make the case for a two-sprint refactor to a product manager under delivery pressure?
2 min answer
3 terms in this topic
Deliberate Technical Debt
A consciously chosen shortcut, recorded with its cost and a repayment trigger, as distinct from debt incurred by carelessness.
conceptDelivery versus Maintainability
Shipping faster now by accepting future cost — a legitimate trade when it is deliberate, recorded and repaid.
conceptExpensive-to-Change Core
The small part of a system whose shape is copied into stored data and into other people's code, where a shortcut cannot be repaid locally - so delibe…
Neighbouring topics
Architecture Decision-Making
General material on making and recording architectural decisions.
Architecture Decision Records
One decision, its context, alternatives and consequences, kept immutable.
Reversibility
One-way and two-way doors, and buying optionality deliberately.
Build vs Buy
Differentiation, five-year TCO, and the exit cost of each option.
Monolith vs Microservices
A team-topology decision far more often than a technology one.
SQL vs NoSQL
Decided by access patterns and query flexibility, not by data volume.
Sync vs Async
Whether the caller's outcome depends on the callee's response.
Strong vs Eventual Consistency
A per-operation decision, resolved by what a stale read would cost.
Managed vs Self-Managed
Trading control and unit cost against operational attention.
Serverless vs Containers
Spiky and event-driven versus sustained throughput.
Single vs Multi-Region
Driven by RTO, RPO and residency rather than by ambition.
Centralised vs Distributed
Shared platform leverage against team autonomy.
Performance vs Cost
Buying latency, and knowing what the last millisecond is worth.
Reliability vs Complexity
Mechanisms that add availability and add failure modes.
Security vs Usability
Varying control by the value of the action rather than uniformly.
Deciding Under Uncertainty
Bounding the downside and buying information cheaply.
Trade-off Analysis Methods
ATAM, scenarios, and naming the points where qualities conflict.
Technology Selection
Evaluating options against drivers rather than against enthusiasm.
Decision Practice
Thresholds, review, supersession and keeping the log alive.