# Feasibility Spike

> [discovery-phase pack · validation] Time-boxed engineering investigation targeting the top feasibility assumptions from risk-assumption-map. Produces tech-spike-report.md and disposable code. Warns (does not halt) if no engineering capacity is reflected in the engagement context — output is tagged speculative if the BA chooses to proceed solo.

- Skill: `stanislavnianko/feasibility-spike` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add stanislavnianko/feasibility-spike`
- Raw SKILL.md: https://api.skillmd.com/api/skills/stanislavnianko/feasibility-spike/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Product & Planning
- Author: stanislavnianko (https://skillmd.com/u/stanislavnianko)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/stanislavnianko/feasibility-spike

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# Feasibility Spike

> Part of the **discovery-phase** skill pack · `validation` group · reads `discovery-context.md` (run `profile-builder` first if missing).

Kill the biggest technical risks cheaply. Throwaway by contract.

## Step 1 — Read context

Read `discovery-context.md` (section **3. Engagement → Runner role**) and `risk-assumption-map.md` (anchors the spike to a specific assumption).

If `discovery-context.md` is missing, ask the BA inline: "who's running the spike — solo BA / BA + engineer / engineering lead?" — tag the output `[ASSUMED ENGINEERING]`. If `risk-assumption-map.md` is missing, ask: "name 1–3 feasibility assumptions to test in one sentence each" or proceed as open exploration tagged `[EXPLORATION-NOT-SPIKE]`. Never block; recommend `profile-builder` / `risk-assumption-mapping` for high-stakes work.

**Engineering capacity reality-check (warn + confirm, do not halt):** if runner is solo BA with no engineering support, warn that the spike will produce a spike-shaped artifact with weak engineering signal. Offer: loop in an engineer, defer the spike to delivery, skip and accept the risk in the proposal, or proceed solo with a `⚠ NO-ENGINEER-OVERRIDE` banner at the top of `tech-spike-report.md` and findings tagged `[SPECULATIVE]`.

## Step 2 — State spike goal

One sentence. Tie to a specific assumption from risk-map.

> Example: "Prove we can extract structured events from free-text emails with ≥80% precision using a single Claude API call."

## Step 3 — Time box

| Tier | When |
|---|---|
| **Short — 4 hours** | Ruling out a "is this even possible?" question |
| **Standard — 1-2 days** | Validating a specific approach against representative inputs |
| **Escalated — up to 1 week** | Genuinely unknown territory; requires explicit BA + engineering lead sign-off |
| **>1 week** | This is no longer a spike. Re-frame as `prototype-plan`. |

Stop at the time box. Overrunning spikes are how discovery bleeds into delivery.

## Step 4 — Narrowest test

- Use **production-representative inputs**, not cherry-picked
- Throwaway branch / repo named `spike/<topic>` — never merge to main
- Prefer manual scripting over frameworks (frameworks hide what you're testing)
- Logging is essential; UI is irrelevant

## Step 5 — Build minimum, run, measure

Capture:
- What worked, with evidence (screenshots, logs, numbers)
- What didn't, with same
- Surprises — especially newly-discovered constraints
- Rough performance, latency, cost per operation

## Step 6 — Feasibility call

Three outcomes only:

- **Green** — proceed to PoC / MVP as scoped
- **Yellow** — feasible with caveats; caveats become PoC scope constraints
- **Red** — blocker. Escalate before building anything. Options:
  - Re-scope (loop `feature-scoping`)
  - Different solution (loop `opportunity-mapping`)
  - KILL or PIVOT in `go-nogo-memo`

In outsourcing, a Red call before contract = save the engagement (don't sell what can't be built). After contract = harder; either renegotiate scope or eat the loss.

## Step 7 — Archive + tear down

Commit spike code under `./discovery/spike/<topic>/`. Do **NOT** merge to product code. Document tear-down status — was the spike code disposed of, kept as reference, or repurposed?

## Output

- `./discovery/tech-spike-report.md` per `./template.md`
- `./discovery/spike/<topic>/` — disposable code

Append to `_log.md`: `[feasibility-spike | YYYY-MM-DD] goal: <one-line>; box: <hours>; result: <green/yellow/red>; constraints: <list>`.

## Anti-patterns

- **Spike without an assumption.** That's exploration. Useful sometimes, but don't mislabel.
- **Merging spike code.** Spike code skips error handling, tests, polish. Shipping = silent tech debt.
- **Overrun.** "Just one more hour" violates the rule. Stop, report yellow, decide.
- **Hiding red.** A failed spike is a saved project. Surface it; celebrate it.
- **Spike with no time box.** That's R&D. Different cost structure.
- **Skipping prerequisite check** (engineering capacity in context). BA running this solo will produce a spike-shaped artifact with zero engineering signal.