Why Your Bottleneck Isn’t the Model (It’s Your Request Strategy)
Over the last few months, I built several AI products that relied heavily on:
- Embedding generation
- LLM API calling (chat/completions)
- Real-time or near real-time responses
On paper, everything looked great: solid models, decent infra, and reasonable traffic.
But in reality, things fell apart much faster than expected:
- API usage limits were exhausted within hours of load testing
- Token consumption grew non-linearly as user traffic increased
- Latency spikes made responses unusable under peak load
- Costs climbed aggressively with every deployment
- And yes — I even got penalized for exceeding consumption limits 😅
Like many engineers, my initial reaction was:
“We need more compute. Bigger models. More parallelism.”
I was wrong.
What I eventually realized was this:
Most AI systems don’t fail because the model is weak —
they fail because the infrastructure calling the model is inefficient.
I wasn’t architecting for scale.
I was brute-forcing the problem by firing more and more requests at the model and assuming hardware would magically handle the load.
After researching distributed inference systems, batching strategies, caching layers, vector storage, and reading several research papers, one pattern became clear across high-performance AI stacks:
Efficient AI isn’t achieved by calling the model more —
it’s achieved by reducing unnecessary calls.
In this article, I’ll break down the three system-level engineering strategies that dramatically improved cost, latency, and throughput:
- Semantic Deduplication
- Intelligent Request Batching
- Meaning-Based Caching
🧠 1️⃣ Semantic Deduplication
Stop Answering the Same Question Twice
🧩 The Problem
Real-world traffic is extremely repetitive:
- Users ask the same question in slightly different wording
- Different clients send near-identical prompts
- Automated pipelines generate repeated instructions
In most LLM-backed applications, 30–60% of requests are paraphrased variations of something already processed — but the system still sends a brand-new LLM request every time.
That’s pure waste.
💡 The Solution
Instead of assuming every request is unique, compare incoming requests against stored embeddings:
- Convert incoming text into an embedding vector
- Compute similarity with previous embeddings
- If similarity ≥ threshold (e.g. 0.9 cosine similarity) → reuse the previous response instead of calling the model again
Example:
“How do I reset my password?”
“How can I change my login password?”
Different text — same meaning → one inference, unlimited reuse.
🏗️ Architecture Flow
- Client sends a request
- Compute embedding
- Search vector store for nearest match
- If
similarity ≥ threshold→ return previous response - Else call LLM & store new embedding/response
🧪 Pseudo-Code Example
from typing import Optional
import numpy as np
vector_store: list[tuple[np.ndarray, str]] = []
SIMILARITY_THRESHOLD = 0.9
def cosine_similarity(a: np.ndarray, b: np.ndarray) -> float:
return float(a @ b / (np.linalg.norm(a) * np.linalg.norm(b) + 1e-8))
def find_similar_response(query: str) -> Optional[str]:
if not vector_store:
return None
q_emb = get_embedding(query)
best_sim = -1.0
best_resp = None
for emb, resp in vector_store:
sim = cosine_similarity(q_emb, emb)
if sim > best_sim:
best_sim, best_resp = sim, resp
return best_resp if best_sim >= SIMILARITY_THRESHOLD else None
def handle_request(query: str) -> str:
cached_resp = find_similar_response(query)
if cached_resp:
return cached_resp
response = llm_call(query)
q_emb = get_embedding(query)
vector_store.append((q_emb, response))
return response
⚖️ Pros & Cons
Pros
- Eliminates 30–60% redundant LLM calls
- Reduces token usage & prevents hitting API limits
- Improves latency significantly
- Simple addition to existing systems
Cons
- Requires vector index (FAISS, Weaviate, Redis, Milvus, pgvector)
- Requires threshold tuning & cleanup logic
- Embedding cost overhead
⚙️ 2️⃣ Intelligent Request Batching
Stop Making the Model Process Requests One-by-One
🧩 The Problem
Traditional request handling:
N users → N separate LLM calls
Each request:
- Has independent overhead
- Causes concurrency pressure
- Under burst loads, creates bottlenecks
💡 The Strategy
Batch incoming requests within a short time window:
- Collect requests into a buffer queue
- When batch size or timeout is reached, send all at once
- Split results for callers
Ideal for:
- Embedding generation
- Document summarization
- High-traffic chat systems
🧪 Example Batch Worker
import threading
import time
from queue import Queue
REQUEST_QUEUE = Queue()
BATCH_SIZE = 16
MAX_WAIT_MS = 50
def llm_batch_call(prompts: list[str]) -> list[str]:
...
def batch_worker():
while True:
batch_prompts = []
batch_callbacks = []
start_time = time.time()
while (len(batch_prompts) < BATCH_SIZE and
(time.time() - start_time) * 1000 < MAX_WAIT_MS):
try:
prompt, callback = REQUEST_QUEUE.get(timeout=0.01)
batch_prompts.append(prompt)
batch_callbacks.append(callback)
except:
pass
if not batch_prompts:
continue
responses = llm_batch_call(batch_prompts)
for resp, cb in zip(responses, batch_callbacks):
cb(resp)
threading.Thread(target=batch_worker, daemon=True).start()
def handle_request_async(prompt: str, callback):
REQUEST_QUEUE.put((prompt, callback))
📈 Real-World Improvement Results
- 10× higher GPU utilization
- 2–4× lower latency (p95/p99)
- Fewer API calls → prevents hitting rate limits
- Major cost savings
⚖️ Pros & Cons
Pros
- Greatly improves hardware utilization
- Reduces provider-side overhead
- Smoother performance under bursty traffic
Cons
- Adds small latency for individual requests (batch wait window)
- Requires queue management & back-pressure handling
- More complex error handling and observability
💾 3️⃣ Meaning-Based Caching
Stop Paying for the Same Logic Twice
🧩 The Problem
String-based caching fails when users change wording:
cache_key = hash(prompt_string)
Even tiny text differences cause cache misses.
💡 The Improvement
Use semantic vector caching:
- Store
(embedding, response) - Compute similarity for new queries
- If high semantic similarity → return cached result immediately
🧠 Practical Impact
Before vs After:
- 400–2000ms response → 3–10ms response
- Full token cost → Zero token cost
- Recompute logic → Instant reuse
Best Use Cases
- FAQ bots
- Support automation
- Repeated prompt pipelines
- Enterprise workflows
⚖️ Pros & Cons
Pros
- Massive latency reduction on repeated traffic
- Zero extra token cost for cache hits
- Works extremely well with semantic deduplication
Cons
- Needs a vector DB or efficient in-memory index
- Requires good cache invalidation / TTL policy
- Extra memory overhead for embeddings + responses
🔗 End-to-End Optimized LLM Pipeline
Conceptually, the end-to-end pipeline looks like this:
You’ve now shifted from:
“Every request hits the LLM”
to:
“Only truly unique requests hit the LLM — and even those are batched.”
That change alone can reduce token cost by 60–90% depending on domain load patterns.
🧠 Technical Insight
We’re entering a stage where:
- Model quality is converging across providers
- Hardware is expensive and shared
- Latency and cost matter as much as accuracy
So the real differentiator is no longer:
“Which model do you use?”
but instead:
“How intelligently do you orchestrate compute?”
Smarter token flow →
lower cost →
higher throughput →
better UX →
real scalability.
That’s the difference between:
- ❌ Prototype demos that break under real users
- ✅ Production systems that scale to millions
🚀 Where to Go Next
If you want to turn this into a real engineering project, build:
📦 1. A middleware that provides:
- Semantic deduplication
- Intelligent batching
- Meaning-based caching
- A single API entrypoint
📊 2. A benchmarking suite that measures:
- Tokens consumed
- Median / p95 / p99 latency
- Cache hit / miss ratios
- Requests per second throughput
🧑💻 3. A public GitHub repo including:
- Architecture diagram
- Code examples
- Performance dashboards
- Demo endpoint
That kind of project demonstrates:
“I understand AI infrastructure, not just prompt engineering.”
And that stands out sharply in today’s hiring market.
🎯 Final Takeaway
Efficient AI has little to do with bigger models
and everything to do with smarter compute orchestration.
If you architect the system well —
the model becomes the cheapest part of the pipeline.
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