When should organisations prioritise reducing dependencies instead of adding more open-source libraries?

Organisations should prioritise fewer dependencies when extra libraries do not deliver clear value or when they create avoidable maintenance and risk. The article’s guidance is to keep code simple, set a practical threshold for what should be built in-house, and avoid dependency chains that add complexity without improving security or functionality. That discipline helps reduce repeated work and exposure.

When dependency reduction is the better security choice

Reducing dependencies is usually the right call when a new library adds little functional value, duplicates existing capability, or creates a long-term ownership burden that the team cannot justify. The decision is not about being anti open source, it is about avoiding hidden cost: more code to update, more transitive packages to review, and more failure points to carry in production.

A practical threshold helps. If a dependency does not materially improve delivery speed, correctness, maintainability, or security, it should be treated as optional rather than default. That is especially true when the same outcome can be achieved with existing platform features, standard language libraries, or a small internal implementation that stays easier to understand and support.

For open-source ecosystems, fewer direct dependencies also means fewer transitive dependencies. That matters because supply-chain exposure often arrives indirectly, through a package the team never intended to trust at all. Current open-source security guidance from OpenSSF consistently pushes teams to understand and reduce unnecessary software supply-chain risk rather than rely on package volume as a sign of maturity.

How to judge whether a library earns its place

The best test is whether the dependency changes the outcome enough to justify its lifecycle cost. Look at maintenance cadence, compatibility risk, security review effort, and how much of the code path actually depends on the library. If the answer is “only a thin convenience layer,” that is usually a sign to simplify.

Practical teams should also separate “needs a library” from “would be easier with a library.” Ease is not the same as necessity. A dependency that saves a few hours today but creates recurring upgrade work, API churn, or supply-chain review overhead later is often negative value over the life of the system.

This is where secure engineering discipline matters. Controls that emphasize inventory, vulnerability management, and configuration control support the same judgment: if a component expands the maintenance surface without a clear business or technical gain, the safer default is to remove it. Guidance in CIS Controls v8 reinforces that discipline through asset awareness, secure configuration, and vulnerability handling.

When the dependency touches authentication, tokens, build tooling, or package distribution, the risk goes beyond convenience. In those cases, a smaller dependency set is not only easier to maintain, it also narrows the blast radius if a package is compromised or a maintainer account is abused. That is one reason open-source security programs increasingly focus on dependency minimisation as part of supply-chain hardening, not just cost control.

Why fewer dependencies reduce both maintenance and attack surface

Every added library introduces an extra trust relationship. You inherit the maintainer’s release process, update discipline, transitive graph, and potential exposure to poisoned releases or compromised credentials. That does not mean external libraries are unsafe by default, it means they should be added only when the value is concrete and the ownership model is clear.

The maintenance burden is often underestimated because it accumulates quietly. More dependencies means more version conflicts, more upgrade tests, more license review, more vulnerability triage, and more chances that one package constrains another. Over time, that complexity can slow delivery more than it accelerates it.

Security teams often see the failure mode only after an incident. A package that was introduced for convenience becomes a dependency chain that is hard to audit, hard to replace, and hard to retire. Historical supply-chain incidents documented by PyPI Breach, Nx Package Attack, 2,300+ Credentials Leaked, and LiteLLM PyPI package breach show how quickly package trust can turn into operational exposure when dependencies are added too freely.

Risk and Threat Considerations

Unnecessary dependencies create a larger supply-chain attack surface, and they can also make defensive review slower and less accurate. The more packages you carry, the harder it becomes to know which library introduced a vulnerable path, which transitive package brought it in, or which component must be removed first after compromise.

Failure mechanism: Teams add convenience libraries faster than they can inventory, patch, or replace them, then transitive packages, maintainer compromise, or malicious updates turn a minor dependency decision into a wider compromise path.

Impact: The result can be credential theft, build-system exposure, unstable releases, slower incident response, and higher rollback cost because the dependency graph has become part of the production risk profile.

Standards & Framework Alignment

This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.

CIS Controls v8, SLSA and NIST CSF 2.0 set the governance and control requirements practitioners need to meet.

Framework	Control / Reference	Relevance
CIS Controls v8	CIS-4 — Secure Configuration of Enterprise Assets and Software	Dependency minimisation reduces software and package surface area.
	CIS-7 — Continuous Vulnerability Management	More dependencies mean more components to monitor, patch, and replace.
	CIS-16 — Application Software Security	Library choice affects secure design, code review, and supply-chain risk.
Recommendation — Reduce unnecessary packages to shrink software configuration drift and exposure. Track dependency inventory and remediate vulnerable libraries quickly. Prefer simpler code paths and fewer third-party components in applications.
SLSA	Supply Chain Levels for Software Artifacts	Dependency reduction supports stronger software supply-chain integrity.
Recommendation — Limit third-party dependencies and verify artifact provenance throughout the build.
NIST CSF 2.0	PR.DS-10 — Integrity of Information	Dependency sprawl can undermine software integrity and trust in delivered artifacts.
Recommendation — Reduce unneeded dependencies to strengthen software integrity assurances.

Practitioner Guidance

What to prioritise: Review dependencies that do not materially change security, functionality, or maintainability first. The highest-value candidates for removal are convenience wrappers, duplicated utilities, and libraries that exist only because they were quick to add.

What to verify: Before approving a new library, check whether the same outcome can be achieved with existing platform capabilities, a standard library, or a smaller internally owned module. If you cannot explain the incremental value in one sentence, the dependency is probably not justified.

Common mistake: Treating “widely used” as a substitute for “worth carrying.” Popularity does not remove upgrade work, transitive risk, or the need to understand how the package is maintained.

Practitioner takeaway: Add libraries when they clearly reduce total effort or risk; remove them when they only make the first implementation easier and leave the organisation owning a larger, noisier, less auditable codebase.