Prototype-first - A modern API development workflow Tom Akehurst, CTO and Co-Founder at WireMock Apidays New York 2024: The API Economy in the AI Era (April 30 & May 1, 2024) ------ Check out our conferences at https://www.apidays.global/ Do you want to sponsor or talk at one of our conferences? https://apidays.typeform.com/to/ILJeAaV8 Learn more on APIscene, the global media made by the community for the community: https://www.apiscene.io Explore the API ecosystem with the API Landscape: https://apilandscape.apiscene.io/

1. WireMock API Days - Prototype-First Deck | 1
Prototype-first - a
modern API
development
workflow
1
PRESENTED BY:
Tom Akehurst
CTO and co-founder, WireMock
@TomAkehurst

3. WireMock API Days - Prototype-First Deck | 2
“An ounce of practice is worth a
ton of theory”
- Emerson…or Marx…or Schumacher…
or someone else…who knows?

4. WireMock API Days - Prototype-First Deck |
● Model of reality
● Validated via inspection
● Quick + cheap to change
Design
3
● Model of reality
● Validated via inspection
● Quick + cheap to change

5. WireMock API Days - Prototype-First Deck |
● Realised object (with
limitations)
● Validated via use
● Quicker + cheaper to
change than production
item
Prototyping
4
● Realised object (with
limitations)
● Validated via use
● Quicker + cheaper to
change than production
item

6. WireMock API Days - Prototype-First Deck |
● Generally unpopular in today’s development approaches
○ “Big up-front design” = 💩
● “The code is the design”
● Worthwhile when impact of poor design is high e.g. UX
● Generally unpopular in today’s development approaches
○ “Big up-front design” = 💩
● “The code is the design”
● Worthwhile when impact of poor design is high e.g. UX
5
Design & prototyping in software

7. WireMock API Days - Prototype-First Deck |
● Decisions have to be lived with for a long time
● Poor design limits adoption
● Poor design harms productivity
● Serial working lengthens time-to-market
6
API Design & Prototyping - Motivation
● Decisions have to be lived with for a long time
● Poor design limits adoption
● Poor design harms productivity
● Serial working lengthens time-to-market

8. WireMock API Days - Prototype-First Deck |
● Enables verification by inspection - linting, design review
● Helps produce better APIs
But…
● Often adds time and effort up front
● Doesn’t support verification through use
7
API Design
● Enables verification by inspection - linting, design review
● Helps produce better APIs
But…
● Often adds time and effort up front
● Doesn’t support verification through use

9. WireMock API Days - Prototype-First Deck |
● Enables early validation through use
● Supports parallel development
● Enables early validation through use
● Supports parallel development
8
API Prototyping

10. WireMock API Days - Prototype-First Deck |
● Write just enough code to
produce a plausible response
with stubbed/hard-coded data.
● Ship to test environment.
● Long cycle time to test design
changes.
● Simulating more than basic
behaviour involves writing
non-trivial code.
9
Code-a-bit-first API prototyping
● Write just enough code to
produce a plausible response
with stubbed/hard-coded data.
● Ship to test environment.
● Long cycle time to test design
changes.
● Simulating more than basic
behaviour involves writing
non-trivial code.

11. WireMock API Days - Prototype-First Deck |
● Lots of tools available -
OSS, SaaS
● Build prototype out of
stubbed responses
● Much shorter cycle time
than deploying code
● Design/prototyping is not
the primary use case
● Missing capabilities e.g.
spec generation
10
Mocking
● Lots of tools available -
OSS, SaaS
● Build prototype out of
stubbed responses
● Much shorter cycle time
than deploying code
● Design/prototyping is not
the primary use case
● Missing capabilities e.g.
spec generation

12. WireMock API Days - Prototype-First Deck |
● API spec/description is
primary artifact
● Mocks generated from
specs
● OpenAPI and other
description languages not
intended for mocking.
● Generated mocks tend to
be simplistic
11
API design platform with mocking
● API spec/description is
primary artifact
● Mocks generated from
specs
● OpenAPI and other
description languages not
intended for mocking.
● Generated mocks tend to
be simplistic

13. WireMock API Days - Prototype-First Deck |
● Flexible, dynamic mocking
● Bidirectional spec < - > mock generation
● Traffic validation
● Flexible, dynamic mocking
● Traffic validation
● Bidirectional spec < - > mock generation
12
API prototyping platform - WireMock Cloud

14. WireMock API Days - Prototype-First Deck |
Prototyping your APIs:
● Enables verification through use
● Shifts discovery of design shortcomings early in the timeline
● Supports parallel producer/consumer development
13
TL;DR (2)
Prototyping your APIs:
● Enables verification through use
● Shifts discovery of design shortcomings early in the timeline
● Supports parallel producer/consumer development

15. WireMock API Days - Prototype-First Deck | 14
Want to see more?
https://www.wiremock.io/demo
PRESENTED BY:
Tom Akehurst
CTO and co-founder, WireMock
@TomAkehurst