Review

This book is essential reading if you need or want to learn a little more about organisational design. The model in this book is a simplification of a messier reality, but it’s a useful frame of reference. It establishes a limited number of team types and interaction types between teams. The authors then explain how fracture planes and sensing/triggers can help you identify the best team topologies.

You Might Also Like:

Book Review and Summary: The Making of a Manager by Julie Zhuo

Get a comprehensive review and summary of the best-selling book "The Making of a Manager" by Julie Zhuo, the product design and management expert. Learn about the key principles and practices for becoming an effective manager and leader, based on Zhuo's own experience and insights from top executives.

andrewclark.co.uk

Book Review and Summary: The Mythical Man Month by Fred Brooks

Get a comprehensive review and summary of the classic book "The Mythical Man Month" by Fred Brooks, the software engineering and management expert. Learn about the key principles and practices for managing software development projects and teams effectively.

andrewclark.co.uk

Book Summary: Accelerate by Nicole Forsgren, Jez Humble, and Gene Kim

Get a comprehensive review of the best-selling book "Accelerate" by Nicole Forsgren, Jez Humble, and Gene Kim. Discover the key insights and takeaways from this must-read for tech leaders and professionals

andrewclark.co.uk

Key Takeaways

The 20% that gave me 80% of the value.

The Problem with Org Charts, Conways Law and Why it Matters, Team First Thinking

• Two problems with traditional org charts:
• They’re often out of date (office politics make them hard to update and issue) and based on past projects and legacy systems
• They don’t show the interactions and communication between teams. If they did - we might be better able to assess them
• Evaluate your org design through the lens of systems thinking:
• Optimising for the whole
• Understanding flow and bottlenecks
• Organisations are complex adaptive systems
• expect to review and iterate over time
• structures should be able to flex and adapt to new conditions

• Explicitly agree interaction models modes with other teams - set clear expectations and build trust

• Team Topologies clarify team purpose and responsibilities, increasing the effectiveness of their interrelationships.

• Design Software Architecture and Org Structures together to take into account Conway’s law
• Clean Conways Law (by Ruth Malan): If the architecture of the system and the architecture of the organisation are at odds, the architecture of the organisation wins
• Reverse/ Inverse Conway Maneuver: change your team and org structure to achieve the desired software architecture you want (as opposed to mandating the architecture design)
• You need to understand what software architecture is needed before you organise teams. Technology leaders need to lead or be involved in team design
• Goal: architecture to support teams to get work done, without requiring high-bandwidth communication between teams

• Restrict unnecessary communication
• Does the structure minimise the number of communication paths between teams?
• Low-bandwidth or Zero-Bandwidth communication between teams is desirable
• Use fracture plane patters to split up software into smaller chunks
• Limiting communication paths to well-defined team interactions produces modular, decoupled systems.
• Tool choices can drive communication patterns. Collaborative teams should have shared tools

• Design Team APIs and Facilitate team interactions. A team API is a description and specification for how to interact with the team. Teams should define, advertise, test and evolve their team API to ensure it’s fit for other consumers

• Restrict the cognitive load of each team until it’s manageable.
• Instead of designing a system in the abstract - design the system and it’s boundaries to fit the cognitive load within teams. Restrict team responsibilities to match cognitive load
• Dan Pink’s 3 elements of intrinsic motivation (autonomy, mastery and purpose) are challenged when a team has too many domains or responsibilities.
• Do you feel like you’re effective and able to respond in a timely fashion to the work you’re asked to do?
‣
Identify the domains a team has to deal with, then classify them by difficulty, divide appropriately
• Assign each domain to a single team
• A single team should be able to accommodate 2-3 simple domains
• A team responsible for a complex domain - shouldn’t have any more domains assigned to them
• Avoid a single team responsible for two complicated domains
• When in doubt - prioritise how the team feels about it

• Optimise for flow of change, bottlenecks and feedback from running systems
• Fast flow requires restricting communication between teams
• The fewer dependencies the better
• Steam-aligned teams are the preferred option
• The speed of software delivery is strongly affected by how many team dependencies the org design instills

• Team-First: take a humanistic approach to system and org design
• Use small long-lived teams as the standard
• The ideal size of teams, groups and divisions depends on the level of trust in the organisation. High trust organisations can have larger collections at each level
• Single Teams - 5-15 max
• Groups of teams - 50-150 max (tribes, families)
• P&L / Division - 150-200 max
• Make work flow to long-lived teams
• Teams take time to be effective (2-12 weeks)
• Keep stability around and within a team so they can reach a high level of effectiveness

• Establish clear boundaries of responsibility for teams.
• Every part of the system needs to be owned by exactly one team. There should be no shared ownership of components, libraries or code
• Team-first mindset = putting the needs of the team above their own
• Reward the whole team, not individuals (allocate a training budget to the team)

• Facilitate Team Interactions to build trust, awareness and learning. Time, space and money

Static Team Topologies, The Four Fundamental Topologies, Choose Team-First Boundaries

• Consciously design your teams into Team Topologies. Teams should be deliberately placed into organisations
• Shape Team Intercommunication to enable flow and sensing
• Considerations when selecting a topology:
• Technical Maturity
• Cultural Maturity
• Organisational size, software scale and engineering maturity
• Remove or lessen dependencies on specific teams by breaking down their set of responsibilities and empowering other teams to take some of them on
• It is essential to detect and track dependencies and wait times between teams

The Four Fundamental Team Topologies

• All teams should move toward one of these types (if not clear cut today)
• Simplifying teams to just these 4 types helps reduce ambiguity within the organisation
• 1) Stream-Aligned Teams
• A continuous flow of work aligned to a business domain or org capability
• Aligned to a single product, service or feature, persona, or user journey
• From idea to deployment, as independently as possible
• Primary team type of the org
• Other team types are there to reduce the burden on steam-aligned teams
• 2) Enabling Teams (technical consulting teams)
• Composed of specialists in a given technical or product domain
• Help bridge the capability gap of stream aligned teams to give them more capacity
• Goal is to increase the autonomy of the stream-aligned teams - by growing their capabilities
• Often focused on one of: build engineering, continuous delivery, deployments, test automation
• Set up a skeleton → initial examples → work with teams to advise on implementation
• Knowledge transfer is likely to be temporary when a new technology is adopted (teams will pair closely in this moment
• 3) Complicated Sub System Teams
• Building and maintaining a sub-system tat depends heavily on specialist knowledge
• Goal: reduce cognitive load of stream-aligned teams
• Wouldn’t be feasible, cost-effective for a stream-aligned team to own that system
• Decision driven by cognitive load - not opportunity of a shared component
• 4) Platform Teams
• Enable stream aligned teams to deliver work with autonomy
• Stream-aligned teams maintain ownership of building, running and fixing their tech
• Platform: self-service APIs, tools, services, knowledge and support which are arranged as a compelling internal product.
• Platforms team value is measured by the value of the services they provide to product teams

• Don’t group functional expertise like UX, Architecture, Data Processing, Database Administration or Testing. That model doesn’t work for safe and rapid change.

• Move to mostly stream-aligned teams for longevity and flexibility
• 6/7 or 9/10 teams should be stream-aligned teams

• Software boundaries or Fracture Planes
• Fracture Plane is a natural seam in the system that allows it to be split easily into multiple parts
• Try to align boundaries with business domain areas -
• Helps with prioritisation, flow and user experience
• Most fracture planes should map to a business-domain bounded context
• Aligning technology to business context - reduces mismatches in terminology, everyone is speaking the same language
• Types of fracture plane: regulatory compliance, team location, change cadence, risk, performance isolation, technology, user personas

Team interaction modes, evolve team structures with organisational sensing

• Most org design team is done as at a ‘point in time’ - we should be thinking about how we want them to evolve and change over time
• Three core team interaction modes:
• Simplifies interactions between teams
• Avoid all teams communicating with all other teams to achieve their goals
• What type of interaction should we be having with this other team? Should we be collaborating closely? Should we be expecting or providing a service? Or should we be expecting or providing facilitation?
• 1) Collaboration
• Driver of innovation and rapid discovery but boundary blurring
• Good for rapid discovery - requires good alignment and high appetite and ability for working together between teams. Bringing together different skill sets to solve a challenge.
• Overlap between teams can be small or almost total
• Teams must take joint responsibility for overall outcomes of their collaboration
• Hit in productivity - so should be for something high value, and on a temporary basis
• Only do it with one team at a time
• Increases innovation and reduces hand-offs
• Context sharing, responsibility challenges, reduced output
• 2) X-as-a-service: Clear responsibilities with predictable delivery but needs good product management
• Best when teams need to use a code library, component, API, or Platform that just works without much effort → where that can be effectively provided as a service by another team
• Consuming or providing something with minimal collaboration
• Requires a high standard of XaaS teams - need to adapt to changing team needs, they need to make the DevEx compelling.
• Clarity of ownership and responsibility
• Reduced detail/context sharing between teams
• Danger of reduced flow if the boundary or API is not effective - the service boundary needs to be well chosen
• 3) Facilitating: Sense and reduce gaps in capabilities
• Where one or more teams would benefit from the active help of another team facilitating or coaching some aspect of their work
• Goal: enable other teams to be more effective, learn more quickly and understand new technology
• Goal: to discover and remove common problems or impediments across the teams
• Typically interact with many teams - not building but focusing on quality of interactions between other teams that are building and running software
• Unblocks stream-aligned teams to increase flow
• Requires experienced staff (to not work on building or running things)
• The interaction may be unfamiliar or strange to one or both teams involved in facilitation

• Associate behaviours to the different interaction modes:
• Collaboration mode: high interaction and mutual respect
• X-as-a-service: emphasise the user experience
• Facilitating mode: help and be helped

• How to choose:

	Collaboration	X-as-a-service	Facilitating
Stream-aligned	Typical	Typical	Occasional
Enabling	Occasional		Typical
Complicated-subsystem	Occasional	Typical
Platform	Occasional	Typical

• Use awkwardness in team interactions to sense missing capabilities and misplaced boundaries

• Triggers for evolution of team topologies
• Software has grown too large for one team
• Delivery cadence is becoming slower
• Multiple business services rely on a large set of underlying services
• Things to sense:
• Have we misunderstood how users need/want to behave?
• Do we need to change interaction modes to enhance how the org is working?
• Build or by discussions about x thing?
• Is the collaboration between two teams still effective? Should we shift modes?
• If the flow as smooth as it could be? What hampers flow?
• Are the promises between the two teams still valid and achievable?
• 3 ways of DevOps from (the DevOps Handbook)
• Systems thinking: optimise for fast flow across the whole organisation, not just parts
• Feedback loops: development informed and guided by operations
• Culture of continual experimentation and learning: sensing and feedback for every team interaction

Deep Summary

Longer form notes, typically condensed, reworded and de-duplicated.

Part 1: Teams as the Means of Delivery

The Problem with Org Charts, Conways Law and Why it Matters, Team First Thinking

• Two problems with traditional org charts:
• They’re often out of date (office politics make them hard to update and issue) and based on past projects and legacy systems
• They don’t show the interactions and communication between teams. If they did - we might be better able to assess them
• Evaluate your org design through the lens of systems thinking:
• Optimising for the whole
• Understanding flow and bottlenecks
• Organisations are complex adaptive systems
• expect to review and iterate over time
• structures should be able to flex and adapt to new conditions

• Empower teams - treat them as the fundamental building blocks
• Explicitly agree interaction models modes with other teams - set clear expectations and build trust
• Org Structure shouldn’t be static - needs to be adaptable

• Team Topologies clarify team purpose and responsibilities, increasing the effectiveness of their interrelationships.
• Team Topologies are a consistent and actionable guide for evolving your team design
• Four Fundamental Team Types
1. Stream-aligned
2. Platfrom
3. Enabling
4. Complicated-Subsystem
• Take into account Conway’s law, cognitive load and flow
• Effective and humanistic approach
• The team is the indivisible element of software delivery - people have a finite cognitive capacity

• Design Software Architecture and Org Structures together to take into account Conway’s law
• Conway’s Law: Organisations which design systems are constrained to produce designs which are copies of the communication structures of these organisations
• Clean Conways Law (by Ruth Malan): If the architecture of the system and the architecture of the organisation are at odds, the architecture of the organisation wins
• If your org design doesn’t compliment your system design - then change one of the two
• Organisations are constrained to produce designs that reflect communication paths.
• An organisation that is arranged in functional silos is unlikely to produce software that is well architected for end-to-end flow
• The design of the organisation constrains the “solution search space,” limiting possible software designs. For any given org structure - there are system designs that can’t be pursued because the communication paths don’t exist
• Monoliths need to be broken down, while keeping a team focus.
• To adapt system designs and make them more amenable to flow → reshape the organisation
• Reverse/ Inverse Conway Maneuver: change your team and org structure to achieve the desired software architecture you want (as opposed to mandating the architecture design)
• You need to understand what software architecture is needed before you organise teams.
• Team assignments are the first draft of your software architecture
• Technology leaders need to lead or be involved in team design
‣
Best Practices for software architecture
• Loose coupling → components don’t have strong dependencies on others
• High cohesion → components have clear bounded responsibilities, their internal elements are strongly related
• Clear and appropriate version compatibility
• Clear and appropriate cross-team testing
• Goal: architecture to support teams to get work done, without requiring high-bandwidth communication between teams
• Software architecture should reflect the flows of change they enable
• Keep things team sized (for ease of understanding)
• Team-first software architecture
• Exploit architecture as an enabler of change. Partition the architecture to absorb change.

• Restrict unnecessary communication
• Requiring everyone to communicate with everyone else is a recipe for a mess. Not all communication and collaboration is good.
• Goal: focused communication between specific teams.
• Notice unaddressed design interfaces and unpredicted team interactions
• Does the structure minimise the number of communication paths between teams?
• Low-bandwidth or Zero-Bandwidth communication between teams is desirable (if you can still build and release great software)
• Communication within teams = high bandwidth
• Communication between two paired teams = mid bandwidth
• Communication between most teams (should be) = low bandwidth
• Use fracture plane patters to split up software into smaller chunks
• Limiting communication paths to well-defined team interactions produces modular, decoupled systems.
• Everyone doesn’t need to communicate with everyone - else systems become monolithic, tangled and highly coupled.
• Tool choices can drive communication patterns.
• Collaborative teams should have shared tools
• Independent teams can have separate tools
• But make information visible

• Design Team APIs and Facilitate team interactions
• Team API: description and specification for how to interact with the team. It includes:
• Code, versioning, wiki and documentation, practices and principles, communication, work information (priorities backlog etc)
• Team API should consider the usability of other teams - Will they find it easy to interact with us?
• Teams should define, advertise, test and evolve their team API to ensure it’s fit for other consumers

• Restrict the cognitive load of each team until it’s manageable.
• Put the team first, consider their cognitive load and restrict it until it’s manageable.
• You don’t want any team to have an excessive amount of responsibilities and domains. Else they won’t be able to pursue mastery
• Dan Pink’s 3 elements of intrinsic motivation (autonomy, mastery and purpose) are challenged when a team has too many domains or responsibilities.
• Make sure the cognitive load on a team isn’t too high!
• Restrict team responsibilities to match cognitive load
• True for both coding and implementation tasks
• Domains, applications, tools, deployments etc
• Definition of cognitive load;
• Intrinsic: aspects of the task fundamental to the problem space
• reduce through training, tech choices, hiring, pair programming
• Extraneous: environment in which the task is being done
• remove boring or superfluous tasks with reduction and automation
• Germane - aspects of the task that need special attention for learning or high performance
• Create more space for this
• Limit the size of the subsystem or area on which the team works
• Do you feel like you’re effective and able to respond in a timely fashion to the work you’re asked to do?
• How to limit the number and type of domains per team:
• When in doubt - prioritise how the team feels about it
• Identify the domains a team has to deal with
• Classify them by difficulty:
• Simple: most of the work has a clear path of action
• Complicated: changes need to be analysed and might require a few iterations on the solution to get it right
• Complex: solutions require a lot of experimentation and discovery
• Compare pairs of domains to fine tune your classification
• Important Heuristics:
• Assign each domain to a single team
• A single team should be able to accommodate 2-3 simple domains
• A team responsible for a complex domain - shouldn’t have any more domains assigned to them
• Avoid a single team responsible for two complicated domains
• Instead of designing a system in the abstract - design the system and it’s boundaries to fit the cognitive load within teams
• Choose somewhere between monolithic and micro-services based to fit the maximum team cognitive load
• A team first approach will favour small decoupled services
• To increase the size of the domain a team looks after:
• provide a team-first working environment
• minimise distractions in the working week
• change the management style by communicating goals and outcomes (eyes on, hands off)
• Minimise the cognitive load for others → heuristic for software development

• Optimise for flow of change, bottlenecks and feedback from running systems
• Choose software architectures that encourage team-scoped flow.
• Fast flow requires restricting communication between teams
• Design the intercommunications between teams - the fewer dependencies the better
• Optimise for flow → steam-aligned teams are preferred
• Occasionally you’ll need a complicated-subsystem team
• The speed of software delivery is strongly affected by how many team dependencies the org design instills
• Team collaboration is important if you’re doing discovery
• Agile, Lean IT and DevOps all demonstrated the value of small autonomous teams aligned to the flow of

• Team-First: take a humanistic approach to system and org design
• Start with the team for effective software delivery
• Make small autonomous teams that are aligned to the flow of the business (Agile, Lean IT and DevOps all agree)
• Teams outperform the equivalent number of individuals for knowledge rich, problem solving tasks
• Teams are essential for modern software development (due to the complexity)
• Who is on the team matters less than the actual team dynamics
• Things to consider: lifespan, size, relationships and cognition

• Use small long-lived teams as the standard
• Stable grouping of 5-9 people
• The team is the smallest unit within an organisation
• In larger teams - trust can erode. You need to design for high trust. Smaller size teams foster trust
‣
Dunbars Number’s / relationship limits
• 5 people - for personal relationships and working memory
• 15 people - for deep trust
• 50 people - for mutual trust
• 150 people - whose capabilities you can remember
• The ideal size of teams, groups and divisions depends on the level of trust in the organisation. High trust organisations can have larger collections at each level
• Single Teams - 5-15 max
• Groups of teams - 50-150 max (tribes, families)
• P&L / Division - 150-200 max
• Make work flow to long-lived teams
• Teams take time to be effective (2-12 weeks)
• Keep stability around and within a team so they can reach a high level of effectiveness
• Teams reach a state when they’re much more effective than a group of individuals
• Flow the work to the team
• Teal Performance Model: Forming, Storming, Norming, Performing

• Establish clear boundaries of responsibility for teams.
• The Team Owns the software
• Team ownership brings continuity of care
• Teams can think multiple horizons out (H1: immediate, H2 few periods, H3 beyond that)
• Every part of the system needs to be owned by exactly one team
• There should be no shared ownership of components, libraries or code
• Team Members need a team-first mindset
• The team is the fundamental means of delivery, not the individual
• Team members should put the needs of the team above their own:
• Arrive for stand-ups on time
• Keep discussions and investigations on track
• Encourage a focus on team goals
• Help unblock others before starting new work
• Mentor new or less experienced team members
• Don’t aim to win arguments - agree to explore options
• Remove ‘team toxic’ people before the damage is done
• Embrace Diversity in Teams
• Diverse mix of people fosters better results
• Variety of viewpoints and experiences helps a team traverse landscape of solutions faster
• Reward the whole team, not individuals (allocate a training budget to the team)

• Facilitate Team Interactions to build trust, awareness and learning
• Ultimately makes teams go faster.
• Time, space and money are required for people to develop their professional competencies
• Make learning and trust building part of the rhythm that facilitates effective team interactions
• working environment (enable interaction) - Red Hat put everything on wheels!
• time away from that in guilds, or communities of practice

Part 2: Team Topologies that Work for Flow

Static Team Topologies, The Four Fundamental Topologies, Choose Team-First Boundaries

• Consciously design your teams into Team Topologies
• Teams should be deliberately placed into organisations
• Don’t do Team Design Ad Hoc
• Don’t shuffle team members often
• Questions you should try and answer…
• Given out skills, constraints, cultural and engineering maturity, desired software architecture, and business goals, which team topology will help us deliver results faster or safer?
• How can we reduce or avoid handovers between teams in the main flow of change?
• Where should the boundaries be in the software system in order to reserve viability and encourage rapid flow? How can our teams align to that?
• Design for the flow of change → from concept to working software
• the old model: functional silos between departments, outsourcing and hand-offs
• Shape Team Intercommunication to enable flow and sensing
• Software development isn’t a one way process - we need to act quickly on feedback from live systems
• Functional silo’s (Dev, Test, Transition, BAU) with hand-offs aren’t as good for flow
• Avoid hand-offs by keeping work within the stream-aligned team.
• Make sure operational information flows back to the team
• There is no one-size-fits-all approach to structuring teams for DevOps success
• BUT there are several known bad topologies
• Feature teams require high engineering maturity and trust
• Feature Team: cross-functional, cross-component team that can take a feature from idea to production
• Feature teams need to be self-sufficient - they need to get to production without the help of other teams
• You might need to add communication conduits between feature teams to help with coordination (system architects, integration leads etc)
• Product teams need a support system to be independent (infrastructure, platform, test environments, delivery pipelines)
• The key to making a team autonomous is making sure that any external dependencies are non-blocking
• That often requires self-service capabilities - things built and maintained by other teams
• The SRE model makes sense at scale - relationship changes throughout the lifecycle.
• Considerations when selecting a topology:
• Technical Maturity
• Cultural Maturity
• Organisational size, software scale and engineering maturity
• Low maturity orgs need time to acquire capabilities before going to autonomous E2E teams
• Meanwhile more specialised teams are an acceptable trade-off as long as they collaborate closely

	Low Org Size or Software Scale	High Org Size or Software Scale
High Eng Maturity	E2E ownership with regular collaboration	Both E2E and specialised teams focused on reliability
Low Eng Maturity	Specialised teams with strong collaboration	Specialised teams relying on Platform-as-a-service

• Remove or lessen dependencies on specific teams by breaking down their set of responsibilities and empowering other teams to take some of them on
• think about how team’s capabilities cause dependencies within teams
• It is essential to detect and track dependencies and wait times between teams
• Book Recommendation: Making Work Visible → use a physical dependency matrix or dependency tags.

• The Four Fundamental Team Topologies
1. Stream-aligned
2. Platfrom
3. Enabling
4. Complicated-Subsystem
• All teams should move toward one of these types (if not clear cut today)
• Simplifying teams to just these 4 types helps reduce ambiguity within the organisation
• 1) Stream-Aligned Teams
• A continuous flow of work aligned to a business domain or org capability
• Clarity of purpose and clear responsibilities between teams is key
• Aligned to a single product, service or feature, persona, or user journey
• From idea to deployment, as independently as possible
• Primary team type of the org
• Other team types are there to reduce the burden on steam-aligned teams
• Close to the customer, quick to act on feedback
• The flow of work is clear and steady
‣
8 Capabilities of a stream aligned team:
1. Security
2. Commercial and operational viability analysis
3. Design and architecture
4. Infrastructure and operability
5. Metrics and monitoring
6. Product management and ownership
7. Testing and quality assurance
8. User Experience (UX)
• Why not a feature team or product team?
• Aligning to a stream focuses on flow
• Customers interact with brands in many different ways
• It can be hard to understand what the responsibilities of a product team are
‣
8 Expected Behaviours
1. produce a steady flow of feature delivery
2. quick to course correct based on feedback from latest changes
3. experimental product evolution, learn and adapt
4. minimal hand-offs to other teams
5. evaluated on the sustainable flow of change it produces {I don’t like this}
6. time and space to address technical debt
7. proactively reaches out to supporting teams
8. achieving autonomy, mastery and purpose
• 2) Enabling Teams
• Composed of specialists in a given technical or product domain
• Help bride the capability gap of stream aligned teams to give them more capacity
• Enabling teams have the bandwidth to research tools, practices and frameworks
• Strongly collaborative - they want to understand and solve problems of stream-aligned teams
• Alternative Name: technical consulting teams
• Help other teams understand technology constraints in the org
• Goal is to increase the autonomy of the stream-aligned teams - by growing their capabilities
• Often focused on one of: build engineering, continuous delivery, deployments, test automation
• Set up a skeleton → initial examples → work with teams to advise on implementation
• Knowledge transfer is likely to be temporary when a new technology is adopted (teams will pair closely in this moment
‣
5 Expected Behaviours
• understand needs of stream-aligned teams through regular checkpoints
• research and experimentation with new tooling and practices
• helps teams understand best practice and avoid mistakes
• act as a proxy for any internal or external services which are too difficult for stream-aligned teams to use
• curator that facilitates appropriate knowledge sharing
• Not a community of practice, but does some of the same things. They work on enabling activities full time
• 3) Complicated Sub System Teams
• Building and maintaining a sub-system tat depends heavily on specialist knowledge
• Goal: reduce cognitive load of stream-aligned teams
• Capabilities / expertise that is hard to find or grow
• Wouldn’t be feasible, cost-effective for a stream-aligned team to own that system
• Decision driven by cognitive load - not opportunity of a shared component
• Expected behaviours
• high collaboration with stream-aligned teams
• delivery speed and quality is clearly higher that if done by stream-aligned team
• Prioritised and delivers work respecting the needs of stream-aligned teams
• 4) Platform Teams
• Enable stream aligned teams to deliver work with autonomy
• Stream-aligned teams maintain ownership of building, running and fixing their tech
• Provide internal services (reducing cognitive load of stream-aligned teams)
• Platform: self-service APIs, tools, services, knowledge and support which are arranged as a compelling internal product.
• Autonomous delivery teams can make use of the platform to deliver product features at a higher pace, with reduced coordination
• Ease of use is fundamental for platform adoption
• Reliable, usable, and fit for purpose
• Platforms team value is measured by the value of the services they provide to product teams
• Can agree different levels of service for services
• Expected Behaviours
• Strong collaboration with stream-aligned teams to understand their needs
• fast prototyping, fast feedback from other teams
• focus on usability and reliability
• leads by example, dogfoods
• encourages adoption (expects to follow adoption curve)
• A platform team can have multiple nested platform teams within it if needed

• Don’t group functional expertise like UX, Architecture, Data Processing, Database Administration or Testing
• That model doesn’t work for safe and rapid change.

• A good platform is just big enough
• Make sure platform teams are serving the needs of their internal customers
• Make it easy for internal teams to do things the right way
• Thinnest viable platform - can start with a wiki
• Platforms generally succeed by reducing the complexity of underlying systems while exposing enough functionality to be useful
• Platform teams need to focus on UX and Developer Experience (DevEx)
• Should get out of the way of the dev teams
• Think about the experience of an new developer in a customer team
• Treat the platform as a live production experience
• Use Product Management and Service management techniques within platform teams
• Have user persona’s etc

• Move to mostly stream-aligned teams for longevity and flexibility
• 6/7 or 9/10 teams should be stream-aligned teams
• Infrastructure teams → platform teams
• Change old component teams to platform teas
• Component teams → platform or complicated-subsystem team
• Align support teams to streams of change → keeps streams independent, rapid sharing within streams

• Software boundaries or Fracture Planes
• Fracture Plane is a natural seam in the system that allows it to be split easily into multiple parts
• Try to align boundaries with business domain areas -
• Helps with prioritisation, flow and user experience
• Most fracture planes should map to a business-domain bounded context (a unit for partitioning a larger system into smaller parts, each of which represents an internally consistent business domain area)
• Also known as Domain Driven Design
• Aligning technology to business context - reduces mismatches in terminology, everyone is speaking the same language
• Types of fracture plane: regulatory compliance, team location, change cadence, risk, performance isolation, technology, user personas/

Part 3: Evolving Team Interactions for Innovation and Rapid Delivery

Team interaction modes, evolve team structures with organisational sensing

• Most org design team is done as at a ‘point in time’ - we should be thinking about how we want them to evolve and change over time
• Three core team interaction modes:
• Collaboration: working closely together with another team
• X-as-a-service: consuming or providing something with minimal collaboration
• Facilitating: helping another team(s) to clear impediments
• Simplifies interactions between teams
• Well-defined interactions are key to effective teams. Helps us assess effectiveness between teams, in turn interfaces are likely to be reflected in software systems too
• We want to avoid all teams communicating with all other teams to achieve their goals
• What type of interaction should we be having with this other team? Should we be collaborating closely? Should we be expecting or providing a service? Or should we be expecting or providing facilitation?
• 1) Collaboration
• Driver of innovation and rapid discovery but boundary blurring
• Suitable when high adaptability or discovery is needed - e.g. exploring new technologies or new techniques
• Good for rapid discovery - requires good alignment and high appetite and ability for working together between teams
• Bringing together different skill sets to solve a challenge
• Overlap between teams can be small or almost total
• Teams must take joint responsibility for overall outcomes of their collaboration
• Hit in productivity - so should be for something high value, and on a temporary basis
• Only do it with one team at a time
• Increases innovation and reduces hand-offs
• Context sharing, responsibility challenges, reduced output
• 2) X-as-a-service: Clear responsibilities with predictable delivery but needs good product management
• Best when teams need to use a code library, component, API, or Platform that just works without much effort → where that can be effectively provided as a service by another team
• Consuming or providing something with minimal collaboration
• Requires a high standard of XaaS teams - need to adapt to changing team needs, they need to make the DevEx compelling.
• Clarity of ownership and responsibility
• Reduced detail/context sharing between teams
• Slower innovation of the boundary or API
• Danger of reduced flow if the boundary or API is not effective - the service boundary needs to be well chosen
• 3) Facilitating: Sense and reduce gaps in capabilities
• Where one or more teams would benefit from the active help of another team facilitating or coaching some aspect of their work
• Facilitating interaction mode is the main interaction mode of enabling teams → providing support and capability to many other teams → helping to enhance the productivity of these other teams
• Goal: enable other teams to be more effective, learn more quickly and understand new technology
• Goal: to discover and remove common problems or impediments across the teams
• Typically interact with many teams - not building but focusing on quality of interactions between other teams that are building and running software
• Unblocks stream-aligned teams to increase flow
• Requires experienced staff (to not work on building or running things)
• The interaction may be unfamiliar or strange to one or both teams involved in facilitation

• Associate behaviours to the different interaction modes:
• Collaboration mode: high interaction and mutual respect
• X-as-a-service: emphasise the user experience
• Facilitating mode: help and be helped

• How to choose:
• Common pairings

	Collaboration	X-as-a-service	Facilitating
Stream-aligned	Typical	Typical	Occasional
Enabling	Occasional		Typical
Complicated-subsystem	Occasional	Typical
Platform	Occasional	Typical

• Use the reverse Conway maneuver with collaboration and facilitating interactions
• Discover effective APIs between teams by deliberate evolution of team topologies
• Choose team interaction modes to reduce uncertainty
• Choose team interaction modes that enhance flow
• Use the collaboration mode to discover viable x-as-a-service interactions
• Change the team interaction temporarily to help a team grow experience
• Use awkwardness in team interactions to sense missing capabilities and misplaced boundaries

• Triggers for evolution of team topologies
• Software has grown too large for one team
• Delivery cadence is becoming slower
• Multiple business services rely on a large set of underlying services
• Things to sense:
• Have we misunderstood how users need/want to behave?
• Do we need to change interaction modes to enhance how the org is working?
• Build or by discussions about x thing?
• Is the collaboration between two teams still effective? Should we shift modes?
• If the flow as smooth as it could be? What hampers flow?
• Are the promises between the two teams still valid and achievable?
• 3 ways of DevOps from (the DevOps Handbook)
• Systems thinking: optimise for fast flow across the whole organisation, not just parts
• Feedback loops: development informed and guided by operations
• Culture of continual experimentation and learning: sensing and feedback for every team interaction