What Is Technical Debt? | Definition, Examples, and Types
Planning for software development involves choosing one way to finish tasks and achieve your objectives. However, things don't always go according to plan, and issues like technical debt can impact the initial project plan.
Sometimes the software development team has to deviate from the original plan and take a shortcut. This is usually due to the various factors that impact decision-making, including changes to the project schedule, budget or resources, or customer feedback.
However, these shortcuts have costs that can affect a project later in its life cycle. The term used to describe this is technical debt, and like any type of debt, it shouldn't be addressed lightly.
Managing technical debt in a project life cycle can make the difference between a failed and a successful software development project. On the other hand, assuming or failing to identify technical debt can result in minimal business rewards and higher development costs. With so much risk, understanding and addressing the technical debt should be a business priority for high-level decision-makers and software developers.
This article is a comprehensive guide to technical debt. It focuses on defining technical debt, its causes, its different types, consequences, and technical debt in Scrum and agile. We also explore some ways to help address technical debt.
Technical Debt Definition
It is the consequence of taking shortcuts or the quickest solution during software development projects rather than the most effective solution to achieve short-term results. Technical debt, a term coined by software developer Ward Cunningham, one of the proponents of the agile manifesto in 1992, is a metaphor that frames how to think about addressing the deficiencies in the internal quality of software systems, thinking of it like financial debt.
The extra effort needed to add new features is similar to the interest paid on the debt.
In a sense, technical debt, also called tech debt or code debt, occurs when a developer chooses an easy solution, like writing sloppy code without complete logic and tests, while developing new features of a digital product to hit a deadline or deliverable. This debt must be paid later with future reworks. It is the cost of prioritizing quick delivery over complete code. The team must return at some point to this project to revise the code or add more functionality.
Speedy code delivery can help your development team meet deadlines, and the tech debt accrued may be worth it, but it could lead to adverse outcomes over the long run if not properly managed.
The technical debt concept is that the accrued "debt" represents the additional development work arising from mediocre code implemented in the short run, despite the code not being the perfect overall solution.
Common Reasons Why Businesses Choose to Make the Tradeoffs Between Speed and Quality
Deadline or financial limitations.
A strategic decision to test a solution for market fit.
Poor software design choices.
Inadequate development skills.
Poor business decisions.
Technical debt functions like any other form of debt: It provides convenience in the short run but accrues payment cost plus interest that must be paid later. Subpar solutions and quick fixes speed up software development but addressing the consequences is expensive, time-consuming, and constraining. Some common symptoms of unaddressed tech debt include:
Product bugs that lead to performance degradation
Longer market release cycles
Code quality issues
Reduced team productivity and agility
Poor user experience
Cybersecurity vulnerabilities
Higher total ownership cost
Scaling difficulties and challenges in adopting new technologies.
Ward Cunningham used the phrase "cruft" to describe the ignored code issues that agile teams must fix to address the technical debt.
Types of Technical Debt
According to Steve McConnell, Chief Software Engineer at Construx Software, there are two primary types of technical debt:
Intentional
Unintentional
1. Intentional Technical Debt
Intentional tech debt occurs when a company consciously decides to optimize the project for the present rather than the future. It involves intentionally delaying the resolution of an issue to achieve a specific goal.
There are both long-term and short-term variations of intentional technical debt. For instance, intentional technical debt accrued to pay off a previous debt is short-term debt, while intentional technical debt accrued to prevent a higher future debt would fall under long-term debt.
Long-term intentional tech debt is often incurred proactively for strategic reasons like meeting a deadline.
On the other hand, short-term intentional tech debt is incurred reactively for tactical reasons like using existing project resources. In addition, short-term tech debt can be focused on individually identifiable shortcuts or unfocused with numerous tiny shortcuts.
2. Unintentional Technical Debt
On the contrary, unintentional technical debt occurs due to accidental mistakes, a lack of understanding, carelessness, or in some cases, poorly written code. For example, a design decision that turns out to be flawed and error-prone. It is the non-strategic cost of making an unavoidable error.
Unintentional technical debt is usually accidental, as the development team did not incur it consciously or on purpose. The mistake is usually only realized after implementing the software update or completing the project.
A few years later, Martin Fowler took Steve McConnell's concept regarding types of technical debt a step further and coined the Technical Debt Quadrant. The four quadrants further break the types of technical debt into four categories based on intent and context. The four quadrants include deliberate, accidental, prudent, and reckless.
Assigning technical debt to these categories helps determine intent and background on software code issues. While some code debt may be inadvertent and classified as bad debt, others may be deliberate and classified as good debt.
Deliberate and Reckless
This occurs when the team knows that a particular decision will lead to technical debt but continues to prioritize speedy delivery despite any possible consequences.
Deliberate and Prudent
This occurs when the development team is aware that the decision to ship quickly will cause technical debt but pushes forward to ship and deal with the consequences later. This type of technical debt is often used when the stakes of the developed product are relatively low, and the benefits of a speedy delivery outweigh the risk. The difference is that, in this case, developers are conscious of the consequences from the beginning and understand that it'll be necessary to revisit and rework the product once there's time for it.
Inadvertent and Reckless
This is the most harmful technical debt type. It occurs when the team isn't applying best practices and blindly implementing a solution without realizing they are accumulating technical debt. The team is often unaware of their mistakes, making it impossible to plan solutions or even measure the negative impact of the accrued debt.
Inadvertent and Prudent
This happens when the development team applies best practices at every stage of the software development project, and there's a desire to produce the best code, but for some reason, it still generates debt. Developers inadvertently create technical debt but prudently find a way to fix the mistakes once the tasks are revisited.
Technical debt can also be classified based on its nature or what the team "owes" rather than whether it was strategic or not, such as:
Architecture debt
Code debt
Build debt
Design debt
Defect debt
Infrastructure debt
Documentation debt
Requirement debt
Process debt
Service debt
Test debt
Bit rot debt
What Causes Technical Debt?
There are several ways that a software development project can accumulate technical debt, but the root causes include the following:
Business causes: Sometimes; company needs may stand in the way of the best development practices. The pressures to release products sooner or for less cost are common business causes of tech debt.
Context changes: In some cases, development plans that seemed to work for the initial design fail to make sense over time. Systems get outdated, and tech stacks change, so developers often take shortcuts to ensure the system remains operational and up-to-date.
Development causes: These causes happen when there is poor documentation, insufficient resources, and a lack of testing in the coding process.
People-based causes: Poor communication, lack of experience, shifting resources, lack of collaboration, and distributed teams are common people-based causes of technical debt.
Other common real-life causes of tech debt are listed below:
An unreasonable timeline that pressures the developers into a quick product release
Insufficient planning where the team starts development before completing the project design to save time
Using a familiar, more straightforward platform rather than an optimal one
Poor-quality design decisions
Lack of appropriate up-front definition of project objectives and goals
Lack of coding skills
Ignorance of technical debt
Lack of product ownership
Relying on fast and risky fixes rather than complete refactoring.
Inadequate testing (QC and QA)
Writing code using insufficient documentation
Lack of flexibility and not being able to pivot when there are changes
Insufficient understanding of software architecture
Last-minute changes to product specifications
Parallel development projects that will require merging in the future.
Neglecting industry standards
Over time, these factors lead to the accumulation of tech inefficiencies that need to be fixed in the future. Unaddressed tech debt may make the product more costly to change than to re-implement.
Is Technical Debt Bad?
Technical debt is much like financial debt and can be either good or bad. Sometimes, technical debt results from a strategic move to meet software timeline pressures and ship good-quality code within sprints. In other cases, technical debt results from an unavoidable mistake when releasing an update.
Most software development teams occasionally trade costs, speed, and quality. And most, if not all, software products have some tech debt. That is why the consensus from several agile teams is that technical debt is not inherently bad. Technical debt only becomes a problem when you:
Aren't aware of the debt.
Ignore the accumulated debt.
A technical debt that is not known or ignored may incur problems for the company, such as:
Stalled Progress
When a tech debt gets out of control, the software development teams are forced to spend so much time paying off piled interest from the former projects instead of addressing critical updates or working on new features. The debt must eventually be paid and comes at the cost of working on other updates or adding new features that move the software product forward. The result is stagnant progress.
Poor Code Design
When developers take the quick and subpar route to meet a deadline, they could skip the standard protocol of developing an organized, clean code leading to messy code with low potential readability. This technical debt will create a backlog of items that involve cleaning the poorly designed code.
Unstable Performance
Pushing out a substandard product could lead to some business benefits. Still, it could also result in challenging consequences such as unstable performance due to bug fixing, engineering bandwidth, and system crashes. Bugs in the code might surface after a fast product release, thus incurring tech debt.
Reduced Productivity
Technical debt drains an organization's productivity resulting in slower outputs. Technical debt will not only lead the development team to slow their build times but also to slow the overall software production-test-release cycle. The team will require more effort and time to identify and manage poorly designed code. New features or changes will only create new bugs in the poorly designed code, making it more challenging for the QA team to test. And once you navigate the code and it is ready for release, you might face an extended schedule and incur profit loss from the lost time on the market.
Strained Testing
When there's a deadline to meet, the QA team will be forced to speed up the testing process. They may possibly miss test issues or promise to solve them later, and tech debt will be incurred to go back and conduct the skipped tests. This has an adverse impact since you are releasing a minimally tested code or rushed through testing.
However, sometimes incurring technical debt may be the optimal decision. Like a sound financial debt, smart tech debt can result in significant benefits in some instances. Strategic technical debt can help:
Deliver minimal viable product (MVP) solutions early
Determine product-market fit
Confirm the product's proof-of-concept
Receive quick feedback
Solve customer needs fast
The impact of technical debt on a project relies on how the development team handles what they owe. Tech debt can be useful if an organization consciously decides to incur debt and has the knowledge and resources to pay the debt off later.
Technical debt is also often inevitable. Software development is ever-evolving, so every product needs maintenance and revisiting.
Technical Debt in Scrum and Agile
Scrum and agile have become popular frameworks that enable developers to reduce the scope of a release to deliver high-quality products instead of many functions. Technical debt will likely occur when the scrum team learns more about the problem that needs fixing.
According to a Scrum trainer, there are two types of technical debt in Scrum.
First is the active decision to develop a short-term solution with not-so-perfect code for a speedy delivery. The team expects to improve the code quality later after the initial release. Second is the passive choice, where the team discovers more information regarding the problem they are trying to solve. As needs change, the solutions that worked before may not work now. The code needs refactoring and adjustment and, in turn, contains a certain amount of tech debt.
And according to the scrum guide:
The product owner is accountable for maximizing the value and effort of the development team
The product backlog is the only requirement asset the development team will work on and shall include everything the product needs to be available.
The product owner should discuss the product backlog items efficiently to achieve the sprint goal during sprint planning.
Technical debt in agile can be prevented by:
Prioritizing transparency and spreading awareness about the tech debt
Following best software architectural practices
Aligning product backlog with technical debt
Tracking technical debt
maintaining standardized procedures for new features or experiments
Dealing with technical debt in Scrum is the Scrum team's responsibility.
How Do You Measure Technical Debt?
The following are some of the metrics that can help evaluate the level of technical debt:
Code quality. This quantifies the overall code state by calculating lines of code, cyclomatic complexity, depth of inheritance, and class coupling. Higher quality means less technology debt within the product.
Closed bug vs. new bug. If the team creates a note after fixing a bug, it's possible to calculate how efficiently the developers eliminate software technical debt. If new bugs outpace closed ones, you should make some changes.
Code churn. This identifies the number of times the team replaces or rewrites a line of code after the release. Prolonged high churn in code areas indicates quick fixes or mistakes in iterations.
Cycle time. This evaluates the time between deployment and the first commit. Short cycle time represents a low technical debt.
Code coverage. This evaluates how much code gets executed when performing a testing suite to reveal how efficient code is by determining the number of unused lines.
Technical debt ratio (TDR). It is a ratio of the remediation cost (cost to fix a system) and the development cost (cost of developing the system). This enables you to calculate the overall tech debt future cost.
Technical Debt Examples
Now that you understand how to measure and manage technical debt and some common causes behind intentional and unintentional tech debt, here are some real-life examples.
Example 1: Intentional tech debt
Description: Due to deadline pressure, the development team uses a fast development framework with known flexibility, performance issues, and low functionality capabilities.
Debt: While they meet the deadline, the team must rework the product features after the launch and need additional funds.
Example 2: Unintentional tech debt
Description: Due to a tight deadline, the team uses several junior developers who lack the coding experience to help launch a new software feature without enough senior developers to review each piece of the code and check for efficient functionality.
Debt: Though the team solved most of the problems, the miscommunication between temporary staff support and full-time staff may cause oversight on some bugs in the code. And as a result, the team will need to clean the code to debug the issues post-launch.
While different, the development team will have to pay off the unintentional and intentional technical debt over time.
How to Manage Software Technical Debt
There is no one-size-fits-all magic for getting rid of or reducing technical debt. The tactics for a large team on an enterprise level may not work for a small startup fixing debt issues. However, there are four main ways every company can manage technical debt and keep it under control:
Limit the creation of new technical debt
Maintain a technical debt list within a tracking system and use the tech debt backlog to track progress. Any unresolved technical debt exceeding 90 days old should be considered critical.
Maintain the tech debt list as part of a Scrum backlog treating each technical debt as a Scrum story, and estimate the schedule and effort to pay off each debt.
Pay back existing tech debt as regularly and efficiently as possible.
These tactics can enable you to effectively track technical debt and reduce debt as efficiently and quickly as possible. Like handling a credit card, these approaches help you pay off small increments of tech debt until the total is paid off.
Key Takeaways
In some situations, incurring technical debt may be the optimal decision that helps you take advantage of the huge market opportunity. However, unresolved technical debt can lead to several problems that drain resources. Too much-accumulated tech debt can result in reduced team morale, slower time to market, poorly written code, reduced agility due to poor security and poorly designed architecture, and eventually volatile overall productivity.
Imagine technical debt as a powerful tool that can make or break your software product development cycle – understand, utilize, and manage it through a long-term view. At Mach One Digital, we help our clients create perfect digital experiences or modernize their existing digital products to help them avoid technical debt. Get started to learn the best practices for controlling technical debt, and contact us for information on the subject.