This document summarizes a Gartner presentation on application architecture trends that enable digital business transformation. It discusses modern application architecture approaches like MASA (Mesh App and Service Architecture), API platforms, and event processing. It recommends adopting these approaches to support agile development, multiexperience applications, and real-time decision making. Specifically, it suggests appointing a leader to build architectural competency, developing a transformation roadmap, modeling capabilities, and taking a continuous modernization approach to prioritize rearchitecting critical systems.

1. © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates. This publication may not be reproduced or distributed in any form
without Gartner's prior written permission. It consists of the opinions of Gartner's research organization, which should not be construed as statements of fact. While the information contained in this
publication has been obtained from sources believed to be reliable, Gartner disclaims all warranties as to the accuracy, completeness or adequacy of such information. Although Gartner research
may address legal and financial issues, Gartner does not provide legal or investment advice and its research should not be construed or used as such. Your access and use of this publication are
governed by Gartner’s Usage Policy. Gartner prides itself on its reputation for independence and objectivity. Its research is produced independently by its research organization without input or
influence from any third party. For further information, see "Guiding Principles on Independence and Objectivity."
Anne Thomas
Top Trends in Application
Architecture That Enable
Your Digital Business
Transformation
Gartner Application Architecture, Development & Integration Summit
2 – 3 March 2020 / Mumbai, India

2. 2 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Sources of Company Value Have Shifted to …
The Experience Economy
Source: B.J. Pine and J. H. Gilmore. “The Experience Economy.” Harvard Business Press. 2011.
The Progression
of Economic
Value
Competitive
Position
Differentiated
Undifferentiated
Market Premium
Pricing
Deliver
Experiences
Provide
Services
Make
Goods
Extract
Commodities

3. 3 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Leveraging
Ecosystems
What Is the Future “Experience” of Applications?
Multiexperience
Embedded
Intelligence
Context Aware
Continuous
Improvement
Optimized for Role/
Customer/Task
Free-flow of
Information

4. 4 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
What Is the Future “Experience” of Applications?
Leveraging
Ecosystems
Multiexperience
Embedded
Intelligence
Context Aware
Continuous
Improvement
Optimized for Role/
Customer/Task
Free-flow of
Information
This Future “Experience”
Requires Modern
Application Architecture

5. 5 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Architecture Trends for Digital Transformation
MASA
API
Platform
Event
Processing

6. 6 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Architecture Trends for Digital Transformation
MASA
API
Platform
Event
Processing

7. 7 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Outer APIs
Inner APIs
Multigrained Services
Service
Service
Service
DB
Service
Service
Mediation
API Mediation Layer
Multiexperience
Service
Service
DB
DB
Mesh App and Service Architecture
Fit-for-purpose apps
Multiple personas
Multiple modalities
Monitoring
Security
Traffic management
Transformations
Micro, Mini, Macro Services
New and Legacy Systems
On-Prem. and Cloud-Based
Purchased and Homegrown
Self-Managed and Third-Party

8. 8 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Multigrained Services
DXP iBPMS xPaaS AI Services MXDP
API Mediation
Mobile Apps,
PWAs, AR/VR
Web, Chatbots Web, Voice AR/VR, Voice Voice
CRM ERP SCM Marketing Commerce
Multiexperience: Fit-for-Purpose Experiences for
Multiple Personas

9. 9 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Multigrained Services
DXP iBPMS xPaaS AI Services MXDP
API Mediation
Mobile Apps,
PWAs, AR/VR
Web, Chatbots Web, Voice AR/VR, Voice Voice
Type Touch Chat Gestures Voice
CRM ERP SCM Marketing Commerce
And Multiple Modalities

10. 10 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Inner
APIs
Service
Service
Service
Service Service
Shared back-end
services
API Mediation Layer
Outer
APIs
Distinct apps for
different personas
and modalities
Back-end for frontend
(BFF) APIs support
distinct experiences
Service
BFF API
(Call Center)
Call Center
Web App
Field Service
Progressive
Web App
BFF API
(Field Service)
BFF API
(Customer)
Customer
Mobile App
Customer
Progressive
Web App
Manager
Mobile App
BFF API
(Manager)
Manager
Web App
Add new
experiences
as needed
Multiexperience Development Model
API API API
API API API
BFF API
(Immersive)
Field Service
Immersive App

11. 11 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
API Mediation Layer
Outer
APIs
Inner
API
Mediation Layer
• Monitoring
• Security
• Traffic Management
• Transformations
Service
Service Multiexperience
Consumers
Multigrained Services
Mediation Ensures Agility, Security and Resiliency

12. 12 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
App
BFF API
JavaScript
Microservice
C#
Miniservice
Java
Microservice
Python
Microservice
API Mediation Layer
App
BFF API
JavaScript
Microservice
API SaaS
Service
Partner
Service
JavaScript
Function
Multigrained Services
• Macro/Mini/Micro/Functions
• New/Old
• On-Prem./Cloud
• Internal/External/Ecosystems
Multigrained Polyglot Back-End Services
API API
Macroservice
Within Java EE
Legacy
Application
API
API API API
API

13. 13 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
API Mediation Must Be Pervasive
BFF API
(Customer)
BFF API
(Call Center)
BFF API
(Immersive)
Customer
Progressive
Web App
Service
Service
Service
Manager
Web App
Call Center
Web App
Field Service
Progressive
Web App
Field Service
Immersive App
Manager
Mobile App
Customer
Mobile App
Service Service
BFF API
(Manager)
BFF API
(Field Service)
API Mediation API Mediation
API Mediation API Mediation
API Mediation API Mediation
API Mediation API Mediation
Service
API Mediation

14. 14 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Spectrum of Service Granularity
Microservice
Fine-grained (feature)
Independently deployable
Owns its data
Private API
Coarse-grained (domain)
Independently deployable
May share data
May publish its API
Large-grained (capability)
Monolithic deployments
Shares data
Publishes its API
Continuous Delivery Improve Agility Enable Access
Granularity
Primary Goal
Principles and
Constraints
Service
Implementation
Model
Miniservice Macroservice
Service API Service API Service API
API implemented by many
independently deployable
microservices
API implemented by a few
independently deployable
miniservices
API encapsulates and provides
access to functionality within
a monolithic application
Monolithic Application
Outer APIs
Inner APIs
API Mediator API Mediator API Mediator

15. 15 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Architecture Trends for Digital Transformation
MASA
API
Platform
Event
Processing

16. 16 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
APIs
Enable Everything:
• MASA
• Multiexperience
• Ecosystems
• Integration
• Intelligence
API

17. 17 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
88%
68%
52%
46%
87%
57%
44%
32%
0% 50% 100%
Internal APIs
Private APIs to Connect With Other
Businesses in Your Network or Support Chain
APIs Provided by Third Parties
Public/Externally Exposed APIs –
Your Organization Exposes
Public APIs for Others to Use
2019
2018
API Usage Is Increasing
2019 Base: n = 112, 2018 Base: n = 129 Gartner Research Circle Members
Q: Does your organization currently use/plan to use .. Select all that apply.
Source: Gartner
Use of API Types
Percentage of Respondents

18. 18 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
APIs Require a Platform Model Mindset
• What APIs do we have?
• What APIs do our consumers need?
• Do our APIs provide access to our business
capabilities?
• How do consumers find APIs?
• How do we facilitate API usage?
• How do we manage API usage?

19. 19 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
API Taxonomy
Dimension Options
Management • Managed (traffic routed through a management proxy)
• Unmanaged/Shadow APIs
Sharing • Published (intended to be shared)
• Unpublished (used within a specific domain)
Constituency • Internal use only
• Private ecosystem (partners, customers)
• Public
Sourcing • Internal (micro, mini, macro)
• Third party (SaaS, ecosystems, partners)

20. 20 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Create Services to Extend Legacy Systems
Core/Legacy Systems
CRM ERP SCM Marketing Commerce
Middle Platform
Data
Aggregate
Data Services
AI/ML
Analytics
New Digital
Capabilities
Integration Services
New Digital
Capabilities
Integration Services
New Digital
Capabilities
Integration Services
API
API
API
API
API
API

21. 21 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Treat Published APIs as Products
Developers
API Product
Manager Developers
API Consumers
• Create solutions using
APIs
Optimize developer experience
Manage the API roadmap
Prepare for API monetization
Articulate the business value of
APIs
API Producers
• Create APIs
• Build and run the
services that deliver
APIs

22. 22 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Build an API Platform
API Marketplace
API Management
API Gateways Developer Portal
Admin Portal
API Mediation
Internal Consumers
Internal APIs Third-Party APIs
External Consumers

23. 23 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Architecture Trends for Digital Transformation
MASA
API
Platform
Event
Processing

24. 24 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Four Popular Event Processing Architectures
Event
Capture
and
Brokering
Simple
Notification
Pub/Sub
Event-Driven
Architecture
Stream Analytics and
Machine Learning +
Event
Sourcing

25. 25 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Time Is Money
Historical
Reactive
Actionable
Predictive/Preventive
Data
Value
Traditional “Batch”
Business Intelligence
Time-Critical
Decisions
Time
Real
Time
Secs Mins Hours Days Months
Time Value of Data

26. 26 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
How Much Latency Can You Afford?
>
Hard Real
Time
< 1 microsec
Financial
Trading
< 10s
microsec
Fraud
Detection
< 1 millisec
Edge
Computing
< 10s millisec
Dashboard
Inferencing
< 100s
millisec
Operational
Insights
seconds
Stream Processing Spectrum

27. 27 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Event
Producers
Applications
Sensors
File systems
Messages
CDC
Clickstream
Collector
Broker
Analytics
Storage
Visualization
Ingest and
Integrate
Enrich, Filter,
Transform,
Aggregate
Index,
Search,
Reporting
Stream Processing Architectural Components

28. 28 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Stream Analytics Application Styles

29. 29 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Event Sourcing and EDA Flip Your Perspective
Event-Driven
State
Svc
App
The source of truth is the data store.
First priority: Preserve data
Events
Events
Svc
App
Data
The source of truth is the log of events.
First priority: React to events

30. 30 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Request-Driven vs. Event-Driven Architecture
Orchestration
Svc 1
Svc 4
Svc 2
Svc 3
Invoke Process
Invoke Svc 1
Invoke Svc 2
Invoke Svc 3
Invoke Svc 4
Composite
Service
Svc 1
Invoke Process
Choreography
Event
Broker
Event 1
Pub
Event 2
Pub
Svc 3
Sub
Event 3
Pub
Svc 2
Sub
Svc 4
Sub
Svc 5
Sub
Svc 6
Sub

31. 31 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Inherently Supports Many-to-Many Communications
Event-Driven Architecture Model
Event
Sources
Event
Consumers
Event Broker

32. 32 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Recommendations

33. 33 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Think MASA, APIs and Events
• Agile architecture
• Multiexperience
• Multigrained services
MASA
• API marketplace
• APIs as products
• API mediation
API Platform
• Real-time decisions
• Stream analytics
• Decoupled systems
Event Processing

34. 34 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
Recommendations
Appoint the right leader to build architectural competency in your organization
Develop a roadmap to transform your IT estate to support digital transformation
Use capability modeling to prioritize efforts
Adopt a continuous modernization approach
Assess your application portfolio for business and technical fitness
Prioritize efforts to rearchitect critical IT systems to MASA
Build essential internal APIs to support integration and legacy extension
Govern your API portfolio by building an API platform
Adopt event processing with discretion where it delivers value

35. 35 © 2020 Gartner, Inc. and/or its affiliates. All rights reserved. Gartner is a registered trademark of Gartner, Inc. and its affiliates.
For information, please contact your Gartner representative.
Recommended Gartner Research
Adopt a Mesh App and Service Architecture to Power Your Digital Business
Anne Thomas and Aashish Gupta (G00392875)
Not Just Microservices: Choose the Right Service Granularity for Your Applications
Aashish Gupta, Anne Thomas and Mark O’Neill (G00386955)
Mediated APIs: An Essential Application Architecture for Digital Business
Aashish Gupta, Anne Thomas and Mark O’Neill (G00351557)
API Mediation Is the Key to Your Multiexperience Strategy
Mark O’Neill, Jason Wong, Elizabeth Golluscio and Marty Resnick (G00353820)
Stream Processing: The New Data Processing Paradigm
Sumit Pal (G00378063)
The 5 Steps Toward Pervasive Event-Driven Architecture
Yefim Natis, Massimo Pezzini, Keith Guttridge and W. Roy Schulte (G00398057)