Linking Modular Structure to Improvement Groups

This text will reveal the direct hyperlinks between completely different cell scaling points,
technical structure and groups. At Thoughtworks we work with many giant enterprises
every presenting completely different issues and necessities when scaling their cell presence.
We determine two widespread issues seen in giant enterprise cell app improvement:

  1. A gradual lengthening of the time it takes to introduce new options to a
    market app
  2. Inside function disparity arising from an absence of compatibility/reusability
    between in-house
    market apps

This text charts the journey one in all our shoppers took when making an attempt to handle these
points. We inform the story of how their organisation had up to now, gravitated in direction of
right options, however was not capable of see the anticipated advantages on account of a
misunderstanding of how these options had been intrinsically

We develop this statement by recounting how the identical organisation was capable of obtain a
60% discount in common cycle time, an 18 fold enchancment in improvement prices and an
80% discount in staff startup prices by shifting their staff topologies to match a
modular structure whereas on the identical time, investing within the developer

Recognising the Indicators

Regardless of the perfect of intentions, software program typically deteriorates over time, each in
high quality and efficiency. Options take longer to get to market, service outages
grow to be extra extreme and take longer to resolve, with the frequent outcome that these
engaged on the product grow to be annoyed and disenfranchised. A few of this may be
attributed to code and its upkeep. Nevertheless, putting the blame solely on code
high quality feels naive for what’s a multifaceted problem. Deterioration tends to develop
over time via a posh interaction of product choices, Conway’s regulation, technical
debt and stationary structure.

At this level, it appears logical to introduce the organisation this text is predicated
round. Very a lot a big enterprise, this enterprise had been experiencing a gradual
lengthening of the time it took to introduce new options
into their retail
cell utility.

As a starter, the organisation had accurately attributed the friction they had been
experiencing to elevated complexity as their app grew- their current improvement
staff struggled so as to add options that remained coherent and in keeping with the
current performance. Their preliminary response to this had been to ‘simply add extra
builders’; and this did work to a degree for them. Nevertheless, finally it turned
obvious that including extra individuals comes on the expense of extra strained communication
as their technical leaders began to really feel the elevated coordination overhead.
Therefore the ‘two
rule promoted at Amazon: any staff must be sufficiently small to be fed by two
pizzas. The idea goes that by proscribing how massive a staff can grow to be, you keep away from the
scenario the place communication administration takes extra time than precise worth creation.
That is sound idea and has served Amazon properly. Nevertheless, when contemplating an
current staff that has merely grown too massive, there’s a tendency in direction of ‘cargo
culting’ Amazon’s instance to attempt to ease that burden…

Limiting Cognitive Load

Certainly, the organisation was no exception to this rule: Their as soon as small monolith had
grow to be more and more profitable however was additionally unable to copy the required charge of
success because it grew in options, tasks and staff members. With looming
function supply deadlines and the prospect of a number of model markets on the
horizon, they responded by splitting their current groups into a number of smaller,
related sub-squads – every staff remoted, managing a person market (regardless of
related buyer journeys).

This in reality, made issues worse for them, because it shifted the communication tax from
their tech management to the precise staff itself, whereas easing none of their
increasing contextual load. Realizing that communication and coordination was sapping
an growing period of time from these tasked with precise worth creation, our
preliminary suggestion concerned the concept of ‘cognitive
outlined by Skelton & Pais (2019). This includes the
separation of groups throughout singular complicated or difficult domains. These seams
inside software program can be utilized to formulate the aforementioned ‘two pizza sized groups’
round. The result’s a lot much less overhead for every staff: Motivation rises, the
mission assertion is clearer, whereas communication and context switching are shrunk
right down to a single shared focus. This was in idea an incredible resolution to our consumer’s
drawback, however can really be deceptive when thought of in isolation. The advantages
from cognitive load limitation can solely actually be realised if an utility’s area
boundaries are actually properly outlined and persistently revered contained in the code.

Area Pushed Self-discipline

Design (DDD)
is helpful for organising complicated logic into manageable teams
and defining a standard language or mannequin for every. Nevertheless, breaking up an
utility into domains is barely a part of an ongoing course of. Preserving tight management
of the
bounded context
is as necessary as defining the domains themselves.
Inspecting our consumer’s utility’s code we encountered the widespread lure of a transparent
preliminary funding defining and organising area tasks accurately, solely
to have began to erode that self-discipline because the app grew. Anecdotal proof from
stakeholders prompt that perpetually busy groups taking shortcuts pushed by
pressing product
necessities had grow to be the norm
for the staff. This in flip had contributed
to a progressive slowing of worth supply because of the accumulation of technical
debt. This was highlighted additional nonetheless by a measurable downtrend within the
utility’s 4
Key Metrics
because it turned tougher to launch code and tougher to debug

Additional warning indicators of a poorly managed bounded context had been found via
widespread code evaluation instruments. We discovered a codebase that had grown to grow to be tightly
coupled and missing in cohesion. Extremely
is tough to alter with out affecting different elements of your system.
Code with low cohesion has many tasks and considerations that don’t match inside
its remit, making it obscure its objective. Each these points had been
exacerbated over time because the complexity of every area inside our consumer’s app had
grown. Different indications got here with reference once more to cognitive load. Unclear
boundaries or dependencies between domains within the utility meant that when a
change was made to at least one, it might probably involuntarily have an effect on others. We seen that
due to this, improvement groups wanted information of a number of domains to resolve
something which may break, growing cognitive load. For the organisation,
implementing rigorous management of every domain-bounded context was a progressive step
ahead in guaranteeing information and accountability lay in the identical place. This
resulted in a limitation of the ‘blast radius’ of any modifications, each within the quantity of
work and information required. As well as, bringing in tighter controls within the
accruing and addressing of technical debt ensured that any brief time period
‘domain-bleeds’ could possibly be rejected or rectified earlier than they may develop

One other metric that was lacking from the organisation’s cell purposes was optionality
of reuse
. As talked about earlier, there have been a number of current, mature model
market purposes. Characteristic parity throughout these purposes was low and a
willingness to unify right into a single cell app was tough on account of a want for
particular person market autonomy. Tight coupling throughout the system had lowered the flexibility
to reuse domains elsewhere: Having to transplant most of an current cell app simply
to reuse one area in one other market introduced with it excessive integration and ongoing
administration prices. Our utilisation of correct domain-bounded context management was a
good first step to modularity by discouraging direct dependencies on different domains.
However as we discovered was not the one motion we wanted to take.

Domains that Transcend Apps

State of affairs 1 – ‘The Tidy Monolith’

When seen as a single utility in
isolation, merely splitting the app into
domains, assigning a staff, and managing their coupling (in order to not breach
their bounded contexts) works very properly. Take the instance of a function request
to a person utility:

function request is handed to the app squads that personal the related area. Our
bounded context implies that the blast radius of our change is contained inside
itself, which means our function will be constructed, examined and even deployed with out
having to
change one other a part of our utility. We velocity up our time to market and permit
a number of options to be developed concurrently in isolation. Nice!

Certainly, this labored properly in a singular market context. Nevertheless as quickly as we
tried to handle our second scaling problem- market function disparity arising
from an absence of reusability
– we began to run into issues.

State of affairs 2 – ‘The Subsequent Market Alternative’

The subsequent step for the group on its quest for modularity of domains was to
obtain fast improvement financial savings by transplanting elements of the ‘tidy monolith’
into an current market utility. This concerned the creation of a standard
framework (features of which we contact on later) that allowed
functionalities/domains to be reused in a cell utility outdoors its origin.
To raised illustrate our methodology, the instance beneath exhibits two market
purposes, one within the UK, the opposite, a brand new app based mostly out of the US. Our US
based mostly utility staff has determined that along with their US particular domains
they wish to make use of each the Loyalty Factors and Checkout domains as
a part of their utility and have imported them.

For the organisation, this appeared to imply an order of magnitude improvement
saving for his or her market groups vs their conventional behaviour of rewriting area
performance. Nevertheless, this was not the top of the story- In our haste to maneuver
in direction of modularity, we had didn’t keep in mind the present
communication constructions of the organisation that in the end dictated the
precedence of labor. Growing our earlier instance as a way to clarify: After
utilizing the domains in their very own market the US staff had an thought for a brand new function
in one in all their imported domains. They don’t personal or have the context of that
area so that they contact the UK utility staff and submit a function request. The
UK staff accepts the request and maintains that it seems like “an incredible thought”,
solely they’re at the moment “coping with requests from UK based mostly stakeholders”
so it is unclear when they’ll be capable of get to the work…

We discovered that this battle of curiosity in prioritising area performance
limits the quantity of reuse a client of shared performance might count on –
this was evident with market groups changing into annoyed on the lack of progress
from imported domains. We theorized a lot of options to the issue: The
consuming staff might maybe fork their very own model of the area and
orchestrate a staff round it. Nevertheless, as we knew already, studying/proudly owning an
complete area so as to add a small quantity of performance is inefficient, and
diverging additionally creates issues for any future sharing of upgrades or function
parity between markets. Another choice we regarded into was contributions through pull
request. Nevertheless this imposed its personal cognitive load on the contributing staff –
forcing them to work in a second codebase, whereas nonetheless relying on assist on
cross staff contributions from the first area staff. For instance, it was
unclear whether or not the area staff would have sufficient time between their very own
market’s function improvement to supply architectural steering or PR critiques.

State of affairs 3 – ‘Market Agnostic Domains’

Clearly the issue lay with how our groups had been organised. Conway’s
is the statement that an organisation will design its enterprise
techniques to reflect its personal communication construction. Our earlier examples
describe a state of affairs whereby performance is, from a technical standpoint
from an
possession standpoint remains to be monolithic:
“Loyalty Factors was created
for the UK utility so it belongs to that staff”
. One potential
response to that is described within the Inverse
Conway Maneuver
. This includes altering the construction of improvement groups
in order that they permit the chosen technical structure to emerge.

Within the beneath instance we advance from our earlier state of affairs and make the
structural modifications to our groups to reflect the modular structure we had
beforehand. Domains are abstracted from a particular cell app and as a substitute are
autonomous improvement groups themselves. Once we did this, we seen
relationships modified between the app groups as they now not had a dependency
on performance between markets. Of their place we discovered new relationships
forming that had been higher described by way of client and supplier. Our area
groups offered the performance to their market prospects who in flip consumed
them and fed again new function requests to higher develop the area product.

The principle benefit this restructuring has over our earlier iteration is the
clarification of focus. Earlier we described a battle of curiosity that
occurred when a market made a request to alter a site originating from inside
one other market. Abstracting a site from its market modified the main focus from
constructing any performance solely for the advantage of the market, to a extra
holistic mission of constructing performance that meets the wants of its
shoppers. Success turned measured each in client uptake and the way it was
obtained by the top person. Any new performance was reviewed solely on the
quantity of worth it dropped at the area and its shoppers total.

Give attention to Developer Expertise to Assist Modularity

Recapping, the organisation now had a topological construction that supported modularity
of parts throughout markets. Autonomous groups had been assigned domains to personal and
develop. Market apps had been simplified to configuration containers. In idea, this
all is sensible – we are able to plot how suggestions flows from client to supplier fairly
simply. We will additionally make excessive stage utopian assumptions like: “All domains are
independently developed/deployed”
or “Customers
‘simply’ pull in no matter reusable domains they want to kind an utility”

In follow,
nevertheless, we discovered that these are tough technical issues to unravel. For instance,
do you preserve a stage of UX/model consistency throughout autonomous area groups? How
you allow cell app improvement if you end up solely answerable for a part of an
utility? How do you permit discoverability of domains? Testability? Compatibility
throughout markets? Fixing these issues is completely doable, however imposes its personal
cognitive load, a accountability that in our present construction didn’t have any
proprietor. So we made one!

A Area to Resolve Central Issues

Our new area was categorised as ‘the platform’. The platform was
basically an all encompassing time period we used to explain tooling and steering
that enabled our groups to ship independently throughout the chosen structure.
Our new area staff maintains the supplier/client relationship we’ve got seen
already, and is answerable for enhancing the developer expertise for groups
that construct their apps and domains throughout the platform. We hypothesised {that a}
stronger developer expertise will assist drive adoption of our new structure.

However ‘Developer Expertise’ (DX) is kind of a non-specific time period so we thought it
necessary to outline what was required for our new staff to ship an excellent one. We
granularised the DX area right down to a set of crucial capabilities – the primary
being, Environment friendly Bootstrapping.

With any widespread framework there may be an inevitable studying curve. developer
expertise goals to scale back the severity of that curve the place doable. Wise
defaults and starter kits are a non-autocratic method of lowering the friction felt
when onboarding. Some examples we outlined for our platform area:

We Promise that:

  • It is possible for you to to rapidly generate a brand new area
    with all related cell
    dependencies, widespread UI/UX, Telemetry and CI/CD infrastructure in a single
  • It is possible for you to to construct, check and run your area
  • Your area will run the identical method when bundled into an app because it does

Observe that these guarantees describe components of a self-service expertise inside a
developer productiveness platform. We due to this fact noticed an efficient
as one which allowed groups that had been centered round end-user
performance to focus on their mission reasonably than preventing their method
via a seemingly infinite listing of unproductive

The second crucial functionality we recognized for the platform area was Technical
Structure as a Service
. Within the organisation, architectural features additionally
adopted Conway’s regulation and because of this the accountability for structure
choices was concentrated in a separate silo, disconnected from the groups
needing the steering. Our autonomous groups, whereas capable of make their very own
choices, tended to want some facet of ‘technical shepherding’ to align on
ideas, patterns and organisational governance. Once we extrapolated these
necessities into an on demand service we created one thing that appears like:

We Promise that:

  • The very best follow we offer will probably be accompanied
    with examples that you may
    use or precise steps you possibly can take
  • we’ll preserve an total
    image of area utilization per app and when wanted,
    orchestrate collaboration throughout verticals
  • The trail to
    manufacturing will probably be seen and proper
  • We are going to work with you”

Observe that these guarantees describe a servant
relationship to the groups, recognizing that everybody is
answerable for the structure. That is in distinction to what some may
describe as command and management architectural governance insurance policies.

One final level on the Platform Area, and one value revisiting from the
earlier instance. In our expertise, a profitable platform staff is one that’s
deeply ingrained with their buyer’s wants. In Toyota lean manufacturing, “Genchi Genbutsu” roughly interprets to “Go
and see for your self”
. The thought being that by visiting the supply of the
drawback and seeing it for your self, solely then can you understand how to repair it. We
realized {that a} staff with the main focus of enhancing developer expertise have to be
capable of empathise with builders that use their product to actually perceive
their wants. Once we first created the platform staff, we didn’t give this
precept the main focus it deserved, solely to see our autonomous groups discover their very own
method. This in the end precipitated duplication of efforts, incompatibilities and an absence
of perception within the structure that took time to rectify.

The Outcomes

We’ve instructed the story about how we modularised a cell app, however how profitable was it
over time? Acquiring empirical proof will be tough. In our expertise, having
a legacy app and a newly architected app throughout the identical organisation utilizing the identical
domains with supply metrics for each is a state of affairs that doesn’t come round too
typically. Nevertheless fortunately for us on this occasion, the organisation was giant sufficient to
be transitioning one utility at a time. For these outcomes, we examine two
functionally related retail apps. One legacy with excessive coupling and low cohesion
albeit with a extremely productive and mature improvement staff (“Legacy monolith”). The
different, the results of the modular refactoring train we described beforehand – a
properly outlined and managed bounded context however with ‘newer’ particular person area groups
supporting (“Area-bounded Context App”). Cycle time is an effective measure right here
because it represents the time taken to ‘make’ a change within the code and excludes pushing
an app to the store- A variable size course of that App sort has no bearing on.

Cellular App Kind Cycle Time
Legacy Monolith 17 days
Area Bounded Context (Avg) 10.3 days

Even when cycle time was averaged throughout all area groups in our second app we noticed a
important uplift versus the Legacy App with a much less skilled staff.

Our second comparability considerations optionality of re-use, or lack thereof. On this
state of affairs we study the identical two cell apps within the organisation. Once more, we examine
one requiring current area performance (with no alternative however to put in writing it
themselves) with our modular app (capable of plug and play an current area). We
ignore the widespread steps on the trail to manufacturing since they don’t have any influence on what
we’re measuring. As a substitute, we deal with the features throughout the management of the
improvement staff and measure our improvement course of from pre-production ‘product
log off’ to dev-complete for a single improvement pair working with a designer

Integration Kind Avg Improvement Time
Non-modular 90 days
Modular 5 days

The dramatically completely different figures above present the facility of a modular structure in
a setting that has a enterprise want for it.

As an apart, it’s value mentioning that these exterior components we’ve got excluded
must also be measured. Optimising your improvement efficiency could reveal different
bottlenecks in your total course of. For instance, if it takes 6 months to create a
launch, and governance takes 1 month to approve, then governance is a relatively
small a part of the method. But when the event timeline will be improved to five
days, and it nonetheless takes 1 month to approve, then compliance
could grow to be the following bottleneck to optimise.

One different benefit not represented within the outcomes above is the impact a staff
organised round a site has on integration actions. We discovered autonomous
area groups naturally seconding themselves into market utility groups in an
try to expedite the exercise. This, we consider, stems from the shift in focus of
a site squad whereby success of its area product is derived from its adoption.

We found two concentric suggestions loops which influence the speed of adoption. The
outer, an excellent integration expertise from the buyer of the area (i.e. the app
container). It is a developer-centric suggestions loop, measured by how simply the
client might configure and implement the area as a part of their total
brand-specific product providing. The interior, an excellent finish person expertise – how properly
the general journey (together with the built-in area) is obtained by the buyer’s
market buyer. A poor client expertise impacts adoption and in the end dangers
insulating the area staff from the precise customers of the aptitude. We discovered that
area groups which collaborate intently with client groups, and which have direct
entry to the top customers have the quickest suggestions loops and consequently had been the
most profitable.

The ultimate comparability value mentioning is one derived from our Platform area.
Beginning a brand new piece of area performance is a time consuming exercise and provides
to the general improvement value for performance. As talked about earlier, the
platform staff goals to scale back this time by figuring out the ache factors within the course of
and optimising them – enhancing the developer expertise. Once we utilized this mannequin
to area groups inside our modular structure we discovered an over 80% discount in
startup prices
per staff. A pair might obtain in a day actions that had
been estimated for the primary week of staff improvement!


By now you must have fairly a rosy image of the advantages of a modular structure
on cell. However earlier than taking a sledgehammer to your ailing monolithic app, it is
value taking into account the restrictions of those approaches. Firstly, and certainly most
importantly, an architectural shift equivalent to this takes a whole lot of ongoing time and
. It ought to solely be used to unravel severe current enterprise issues
round velocity to market. Secondly, giving autonomy to area groups will be each a
blessing and a curse. Our platform squad can present widespread implementations within the
type of smart defaults however in the end the alternatives are with the groups themselves.
Naturally, coalescing on platform necessities equivalent to widespread UI/UX is within the
curiosity of the area squads in the event that they want to be included/accepted right into a market
app. Nevertheless, managing bloat from related inside dependencies or eclectic
is difficult. Ignoring this drawback and permitting the general app to
develop uncontrolled is a recipe for poor efficiency within the arms of the shopper.
Once more, we discovered that funding in technical management, together with sturdy
guardrails and pointers helps to mitigate this drawback by offering
structure/design oversight, steering and above all communication.


To recap, at the beginning of this text we recognized two important supply
issues exhibited in an organisation with a multi app technique. A lengthening of
the time it took to introduce new options into manufacturing
and an growing
disparity between different related in home purposes
. We demonstrated that
the answer to those issues lies not in a single technique round technical
structure, staff construction or technical debt, however in a concurrently evolving
composite of all these features. We began by demonstrating how evolving staff
constructions to assist the specified modular and domain-centric structure improves
cognitive and contextual load, whereas affording groups the autonomy to develop
independently of others. We confirmed how a pure development to this was the
elevation of groups and domains to be agnostic of their originating
utility/market, and the way this mitigated the results of Conway’s regulation inherent with
an utility monolith. We noticed that this variation allowed a client/supplier
relationship to naturally happen. The ultimate synchronous shift we undertook was the
identification and funding within the ‘platform’ area to unravel central issues
that we noticed as a consequence of decoupling groups and domains.

Placing all these features collectively, we had been capable of reveal a 60% discount in
cycle time
averaged throughout all modular domains in a market utility. We additionally
noticed an 18 fold enchancment in improvement value when integrating modular
domains to a market app reasonably than writing from scratch. Moreover, the deal with
engineering effectiveness allowed our modular structure to flourish because of the 80%
in startup prices
for brand new domains and the continuing assist the ‘platform staff’
offered. In real-terms for our consumer, these financial savings meant with the ability to capitalise
on market alternatives that had been beforehand thought of far too low in ROI to
justify the trouble – alternatives that for years had been the uncontested domains
of their rivals.

The important thing takeaway is {that a} modular structure intrinsically linked to groups will be
extremely useful to an organisation underneath the appropriate circumstances. Whereas the
outcomes from our time with the highlighted organisation had been glorious, they had been
particular to this particular person case. Take time to know your personal panorama, look
for the indicators and antipatterns earlier than taking motion. As well as, don’t
underestimate the upfront and ongoing effort it takes to carry an ecosystem like
that which we’ve got described collectively. An sick thought of effort will greater than
probably trigger extra issues than it solves. However, by accepting that your scenario
will probably be distinctive in scope and thus resisting the pull of the ‘cargo cult’: Specializing in
empathy, autonomy and contours of communication that allow the structure on the
identical time, then there may be each cause you can replicate the successes we’ve got

Latest articles

Related articles

Leave a reply

Please enter your comment!
Please enter your name here