The headline numbers tell a story of explosive growth. Metric mentions across the reviewed studies surged from just three in 2020 to fifty-three in 2024, a roughly seventeen-fold expansion that mirrors the maturation of Function-as-a-Service platforms such as AWS Lambda, Azure Functions, and Google Cloud Run. Latency emerged as the dominant research focus, accounting for approximately 31 percent of all 149 metric mentions, followed by cost at 24 percent of the 80-study dataset. This emphasis is hardly surprising: in serverless environments, where functions spin up in ephemeral containers only when triggered by events, every millisecond of delay translates directly into degraded user experience and, thanks to pay-per-use billing, real money. The review’s authors found that roughly 30 percent of the analyzed studies addressed two or more metrics simultaneously, with latency-cost and latency-cold start pairs being the most common combinations—a clear signal that researchers increasingly treat performance optimization as a multi-objective problem rather than a single-variable puzzle.

At the heart of the serverless performance challenge sits the notorious cold start problem. When a function is invoked after a period of inactivity, the platform must provision a new container, allocate CPU and memory, load the function’s code and dependencies, and perform initialization tasks—all before a single line of business logic executes. The review quantifies this cumulative burden as the sum of container preparation time and dependency installation time across a set of functions, and notes that delays can range from milliseconds to several seconds depending on memory allocation, package size, runtime choice, and workload burstiness. Because scale-to-zero policies deliberately terminate idle containers to save money, cold starts are not an accidental flaw but an inherent feature of the serverless economic model, which is precisely why mitigating them without inflating costs has become such an active battleground.

The mitigation arsenal documented in the review is remarkably diverse. Pre-warming strategies keep pools of initialized containers ready for immediate use, while prebaking techniques initialize functions ahead of anticipated demand peaks—effective during predictable load surges but wasteful during quiet periods. Container reuse and sharing approaches hold initialized environments for subsequent invocations, and hybrid models combining these tactics have shown greater cold start reductions than any single method alone. Architectural innovations such as the Function Delivery Network maintain functions in a warm state and orchestrate execution windows, reporting 97 percent less resource use and 45 percent faster responses in serverless video and scientific applications. Application-level solutions also play their part: the FaaSLight framework loads only indispensable code segments on demand, cutting runtime memory usage by up to 57.84 percent without introducing observable latency during warm starts.

Where traditional heuristics reach their limits, machine learning has stepped in with impressive results. The review identifies deep reinforcement learning as the leading ML paradigm in the field, appearing in 10 percent of the studies and excelling at sequence-dependent decision-making where temporal dependencies matter. Concrete numbers underscore the appeal: multi-agent DRL systems have reduced latency by 23 percent and request failures by 34 percent on Azure traces spanning 1,800 functions, while a Proximal Policy Optimization-based model cut cold starts by 38.75 percent, improved memory utilization by 46.73 percent, and decreased overhead by 48.53 percent. Context-aware probabilistic caching achieved a 62.1 percent reduction in system cost and a 69.1 percent drop in cold-start frequency on 14 days of Azure serverless traces. These are not marginal tweaks—they represent order-of-magnitude improvements in how serverless platforms manage the tension between readiness and resource waste.

Yet the review is refreshingly honest about the constraints of learning-based approaches. Gradient-boosted ensemble models such as XGBoost, LightGBM, and CatBoost dominate short-term invocation forecasting because they are accurate and lightweight, but their performance degrades sharply when historical data is sparse or when workloads exhibit concept drift. DRL controllers, for their part, carry substantial training overhead and exploration costs, and their benefits diminish in stable, low-variance environments where simple heuristics deliver comparable performance at a fraction of the complexity. Most models also remain tightly tuned to specific providers or testbeds such as OpenWhisk or AWS traces, making transfer to heterogeneous cloud-edge environments far from trivial. The authors recommend online learning, continual retraining, and multi-objective formulations as the most sustainable paths forward, particularly for deployments where latency, cost, energy, and service-level objectives must be balanced simultaneously.

Cost optimization emerges as perhaps the most economically consequential thread in the analysis. Fine-grained billing models based on GB-seconds or vCPU-hours mean that memory allocation decisions directly shape expenditure: larger allocations execute faster but cost more per second, while leaner configurations prolong execution and can paradoxically increase total charges. The review highlights techniques such as Multi-Layer Container Reuse, which matches containers on base-image similarity rather than exact equality and significantly cuts cold start times, indirectly reducing the need for expensive pre-warming. Metrics like wasted memory time enable dual-objective optimization where providers can tune a parameter to prioritize either reduced startup delays or lower memory waste. Balanced provisioning strategies, meanwhile, consistently outperform greedy allocation under dynamic workloads, avoiding the trap of spending heavily early only to gain little for later requests.

Not everything in the serverless performance landscape is flourishing. Throughput stands out as the review’s most glaring gap, with only five mentions across six years of literature and zero studies recorded in 2025—a stagnation the authors classify as critically under-researched, especially for high-concurrency streaming and healthcare IoT workloads where request volume is the binding constraint. Resource allocation, by contrast, shows a steady upward trajectory from 2023 onward, driven largely by multi-tenant scheduling research and DRL-based approaches. The review also points to sustainability as an underexploited opportunity: serverless architectures can reduce energy consumption by up to 70 percent and operational costs by up to 60 percent compared to traditional always-on provisioning, yet energy-aware scheduling that incorporates power models into optimization objectives remains rare. The authors argue that energy consumption and carbon intensity deserve promotion to first-class metrics alongside latency and cost.

The practical guidance flowing from this synthesis is strikingly concrete. Platform developers are advised to prioritize warm-pool sizing and scaling-threshold tuning in multi-tenant settings, and to adopt learning-based schedulers only where workloads are genuinely non-stationary—because DRL’s gains of 23 to 38 percent in latency and cold-start reduction simply do not justify its training overhead for stable traffic. Application developers, meanwhile, should match the optimization paradigm to workload shape, right-size memory and package configurations deliberately, and benchmark latency-cost trade-offs before deployment to locate the inflection point beyond which added resources yield diminishing returns. For researchers, the message is equally clear: treat throughput as an independent optimization target, address cross-platform generalizability and drift head-on, and build unified multi-objective frameworks that integrate latency, cost, energy, and SLA compliance—ideally through DRL-based multi-agent systems.

What emerges from this landmark review is a field in transition, moving decisively from static, rule-based configurations toward autonomous, adaptive optimization powered by machine learning. The seventeen-fold growth in performance research between 2020 and 2024 confirms that serverless computing has graduated from experimental curiosity to production-grade infrastructure serving IoT deployments, AI inference pipelines, and big data analytics. But the transition is incomplete. Hybrid architectures combining serverless elasticity with serverful stability, stateful abstractions for long-running workloads, and cross-platform portable intelligence all remain open frontiers. If the trajectory documented here continues, the next generation of serverless platforms may well manage their own performance—predicting demand, pre-warming containers, and balancing budgets in real time—leaving developers free to do what the paradigm always promised: simply write code.

Subject of Research: AI-driven performance optimization strategies and key metrics in serverless cloud computing, analyzed through a systematic literature review of 80 studies published between 2020 and 2025.

Article Title: AI-driven performance optimization strategies and key metrics in serverless cloud computing: A systematic literature review

Article References: Jarallah, Z. F., Alhussian, H. S., Sumiea, E. H., Eltahir, M., Aziz, N., Abri, A. W. A., Almuniri, I. S., Saidu, Y., & Adamu, S. (2026). AI-driven performance optimization strategies and key metrics in serverless cloud computing: A systematic literature review. Machine Learning with Applications, 25, Article 100994. https://doi.org/10.1016/j.mlwa.2026.100994

Image Credits: AI Generated

DOI: 10.1016/j.mlwa.2026.100994

Keywords: serverless computing, Function-as-a-Service, cold start latency, deep reinforcement learning, machine learning, cloud optimization, auto-scaling, resource allocation, cost optimization, systematic literature review, edge computing, predictive scaling