Understand a system
See a domain as an operational whole before following its implementation seams.
LKCI Engineering Field Guide
How operational systems stay understandable as they grow.
Explore source-backed architecture stories, reusable operating patterns, and field notes from building composable systems.
Choose a question
Find the right level of detail.
Follow a workflow
Trace how intent moves through automation, review, failure, and repair.
Reuse a pattern
Find durable boundaries for data, services, jobs, integrations, and UI surfaces.
Read a field note
Review source-backed context and the decisions that support an architectural claim.
Latest field note
engineering-practice · field-note
Collaboration Is A System, Too
This inaugural note records a week in which the engineering field guide became more than a library of doctrine. The repository added publication governance, a compiler and curated editions, and an isolated browser-quality-assurance lane.…
Current stories
precon · case-study
A Download Is Not Publication
An external file arriving in storage is evidence that something was observed. It is not evidence that the file is the current, relevant, or authoritative document for an operational workflow. In preconstruction, confusing those two events…
platform · case-study
Failures Are Work Items, Not Just Log Lines
An operational workflow regularly encounters missing mappings, ambiguous identities, incomplete evidence, and provider mismatches. Those are not all software defects, and they are not all reasons to stop an entire run. They are often work…
data · case-study
One Database, Several Kinds Of Truth
LKCI currently uses one Postgres database, but it does not treat that physical fact as permission to blur responsibility. Lakehouse schemas hold ingestion, canonicalization, historical truth, enrichment, and analytical publication.…
platform · case-study
Humans And Agents Share Controls
The interesting design question for an engineering agent is not whether it can read a page, write a draft, or suggest a change. It is how that capability enters the operating system around it. LKCI's answer is deliberately ordinary:…
geo · case-study
Geography Becomes An Operating Decision
A map is good at making patterns visible. It is poor at preserving the exact decision that follows from those patterns. LKCI's geo system treats spatial analysis as an operating workflow: source data becomes canonical parcel and feature…
platform · architecture
Platform Layers
The platform layers separate runtime surfaces, capability services, shared contracts, external adapters, deterministic pipelines, executable jobs, and durable documentation.
Evergreen principles
platform · concept
Engineering Principles
The platform is built around composability, explicit ownership, auditability, and future optionality. Velocity matters, but it is not allowed to erase the boundaries that make later work possible.
platform · concept
Pipelines, Jobs, Services, Review Surfaces
The platform uses four recurring shapes to keep work organized: pipelines keep data correct, jobs do automatic work, services expose capabilities, and review surfaces handle stateful human intervention.
platform · concept
Failures Are Data
Recoverable business ambiguity should be captured as structured operational data. It should not be hidden as an exception, buried in logs, or retried until context disappears.
execution · reference
Thin Jobs, Fat Services
Jobs should be executable and readable, but they should not be the primary home for business logic. Reusable behavior belongs in services, libs, integrations, or pipelines.
services · concept
Services Expose Capabilities
Services should expose useful platform or domain capabilities, not table access or provider clients disguised as application code.
integrations · concept
Messy Edge, Typed Inside
Provider APIs can be messy at the edge, but internal platform code should see normalized, typed contracts wherever possible.