Coherent DS: Authoring patterns so feature teams stopped re-solving trust.

A pattern library for Coherent Spark's authoring, diff/review and provenance surfaces — so feature teams could extend the product without re-running the research.

Spark Assistant task pane docked inside Excel — the native placement the system was designed around.

Spark Assistant lives inside Excel — the design system had to feel native to the spreadsheet, not bolted on.

Impact

What moved, and by how much.

03 outcomes

Pattern families with decision logs attached

Feature teams re-running actuarial research

Shared

Authoring grammar across product surfaces

01 · Problem

Every feature team was re-solving trust.

Coherent Spark grew fast. Each new feature team was re-inventing the same authoring, review and audit surfaces — and each was slightly different, which broke actuarial trust across the product.

Eight variations of the Run Solver panel drawn by different teams — surface drift audit.

Eight versions of the same Run Solver panel across teams

02 · Foundations

Logo, task pane, header.

Task pane background — location indicator, aligned header icons, footer with Documentation, Support desk, Logout.

Foundations locked the grammar — a dual‑lockup wordmark that reads on both light spreadsheet chrome and dark headers, and a task‑pane skeleton with a location/mode indicator, centred header actions and a persistent footer for Documentation, Support desk and Logout.

03 · Homescreen

One skeleton, three product states.

Homescreen variations — upload-only, upload + modes, and modes + recently visited.

The homescreen scales with entitlement — from a minimal Upload path, to Upload + Modes, to the full set with recently‑visited services — without changing hierarchy or resetting muscle memory.

04 · Mode selection

A visible mode system.

Mode selection panel — Edit, Analyse, Test, Flow, Admin — with contextual info tooltip surfacing Spark URL, user email and version.

Edit, Analyse, Test, Flow, Admin — each mode is a colour‑coded tile so actuaries always know which surface they're in. Hovering the info marker surfaces the Spark URL, user email and version — the provenance layer stays one hover away, never in the middle of a task.

05 · Flow

Four steps, one docked surface.

Step 01

Landing surface

Spark Assistant docks in Excel as a slim task pane — the design system carries the workbook chrome forward without competing with it.

06 · Components

Button system and mobile progress.

Button matrix — four variants × five states, with icon parity

On mobile, the same authoring grammar collapses into a section list with inline progress. Status chips (Completed, In Progress) and per-section badges keep provenance visible without opening a second surface, and the overall ring anchors the top of the pane.

Mobile progress dropdown — overall progress ring at 75%, section cards with status chips and per-section badges.

Mobile · section progress with status chips

07 · Governance

Decision logs, not just specs.

Trust broke when surfaces diverged

Shared authoring, review, provenance patterns across all feature teams.

Feature teams re-ran research

Decision logs travel with patterns — the research is part of the deliverable.

PR-style review felt alien to actuaries

Documented anti-pattern — no code-review metaphors in authoring surfaces.

“In expert-user products, a pattern without its research is just a component.”

System principle — Coherent DS

Key takeaways

What I'd carry forward.

Ship research with patterns

Decision logs stop teams from re-relitigating solved questions.

Anti-patterns are a deliverable

Naming what not to do is as valuable as prescribing what to do.

Governance before drift

Cross-team pattern reviews earlier prevent silent divergence.

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