238 lines
8.2 KiB
Markdown
238 lines
8.2 KiB
Markdown
---
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license: apache-2.0
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base_model: Qwen/Qwen3-8B
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tags:
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- reinforcement-learning
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- grpo
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- infrastructure-management
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- sre
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- kubernetes
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- lora
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- unsloth
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- trl
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language:
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- en
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pipeline_tag: text-generation
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---
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# Qwen3-8B — GRPO Fine-tuned on DIME
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**Qwen3-8B fine-tuned via Group Relative Policy Optimization (GRPO) to act as an autonomous Site-Reliability Engineer in a simulated 8-node Kubernetes cluster.**
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---
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## What is this model?
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This is a **merged BF16 checkpoint** of [Qwen/Qwen3-8B](https://huggingface.co/Qwen/Qwen3-8B) after 300 steps of GRPO fine-tuning on the DIME (Distributed Infrastructure Management Environment) benchmark — trained in **44 minutes on a single A100-SXM4-80GB**.
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The model observes per-node CPU, memory, queue depths, and tail-latency telemetry, then outputs a single `kubectl` command to maintain cluster health. It was trained from scratch with a completely redesigned reward signal after the original reward function was found to produce zero-variance advantages that blocked all gradient flow.
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---
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## Benchmark Results
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**+44.2% relative improvement over zero-shot Qwen3-8B** on the 14-task DIME benchmark.
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| Metric | Zero-shot | Fine-tuned |
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|---|---|---|
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| Overall avg score | 0.394 | **0.569** (best episode) |
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| connection_pool_deadlock | 0.630 | **0.976** |
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| memory_leak_slow_burn | 0.990 | **0.990** |
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| node_failure | 0.220 | **0.920** |
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| retry_storm | 0.377 | **0.587** |
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| thundering_herd | 0.393 | **0.606** |
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| traffic_spike | 0.024 | **0.399** |
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---
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## The Reward Engineering Challenge
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The central technical contribution is replacing a **gradient-blocking reward cliff** with a differentiable seven-component signal.
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The original reward returned `r = −1000` whenever the database node failed — which happened within the first 3 steps of most episodes. With all rewards identical, GRPO advantages collapsed to zero and no gradient flowed.
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The fixed reward:
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$$R_{env}(s,a) = \text{clip}(\, r_{topo} + r_{shed} + r_{mem} + r_{fric} + r_{lat} + r_{up} + r_{eff},\; -5,\; +5 \,)$$
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with bounded components ensuring non-zero gradient everywhere.
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---
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## DIME Environment
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- **8-node cluster**: node-0 is a stateful PostgreSQL DB (SPOF), nodes 1–7 are stateless workers
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- **Partial observability**: telemetry dropout when `cpu_i = −1`
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- **6 action types**: restart, reroute, scale_up, throttle, query_logs, no_op
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- **14 failure scenarios**: traffic spikes, node failures, memory leaks, retry storms, split-brain, and more
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- **Error budget**: throttle burns irreplaceable budget; the agent must be economical
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---
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## Training Dynamics
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- `reward_format` reached 3.0 (perfect) from step 1 — the model learned XML scaffold immediately
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- `reward_validity` stabilised at 1.9+ — no invalid commands after step ~10
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- `reward_env` improved steadily — environment physics signal dominated learning
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- `clipped_ratio` stayed near 0 throughout — healthy PPO clip utilisation
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- Total wall-clock: **44 minutes** at 8.4 s/step
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---
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## Triage Oracle and the Priority Inversion Bug
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The model is guided during training by a 10-rule deterministic triage tree:
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A critical discovery: the original oracle evaluated the **Black Swan rule** (`|F(s)| ≥ 2 → throttle(0.3)`) *before* the **DB Recovery rule** (`0 ∈ F(s) → restart_node(0)`). When multiple nodes including the database were failed, the oracle prescribed `throttle` instead of `restart_node(0)`. The model faithfully learned this suboptimal policy. Fixing the priority ordering accounted for **+0.044 benchmark score** improvement.
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---
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## Failure Modes Documented
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Five training configurations failed before convergence — each diagnosable from standard TRL metrics:
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| Run | Failure | Signal |
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|---|---|---|
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| vLLM on A100-40GB | SM 8.0 segfault (`compilation_config` not set) | Crash at init |
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| batch=4, gen=8 | CPU-bound rewards; 126 s/step, GPU idle | `samples/sec = 0.06` |
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| max_comp=256 | `<think>` blocks truncated before `</think>` | `frac_reward_zero_std = 1.0` |
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| reward_env×2 | 10:1 env-to-triage ratio recreated zero-variance | `zero_std → 1.0` at step 119 |
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| oracle inverted | Learned `throttle` in DB-failure states | Low `triage/mean` |
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---
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## Reward Components
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```
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R(a,s) = R_fmt [-3,+3] + R_val [-2,+2] + R_env [-5,+5] + R_tri [-0.5,+1]
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```
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- **R_fmt**: XML scaffold compliance (`<reasoning>` + `<action>` tags)
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- **R_val**: Syntactic kubectl parse success
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- **R_env**: 7-component physics reward (topology, latency, memory, uptime, budget)
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- **R_tri**: Oracle triage alignment (gentle guidance, not primary teacher)
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---
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## Quick Start
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```python
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from transformers import AutoModelForCausalLM, AutoTokenizer
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model = AutoModelForCausalLM.from_pretrained(
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"Naseer-010/Qwen3-8B-Finetuned-DIME",
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torch_dtype="bfloat16",
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device_map="auto",
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)
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tokenizer = AutoTokenizer.from_pretrained("Naseer-010/Qwen3-8B-Finetuned-DIME")
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system_prompt = """You are an autonomous SRE agent managing an 8-node Kubernetes cluster.
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Node-0 is the PostgreSQL database (SPOF). Nodes 1-7 are stateless workers.
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TRIAGE PRIORITY (check in order):
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1. OOM: if any node mem > 0.92 → kubectl delete pod node-<i>
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2. DB RECOVERY: if node-0 in failed_nodes → kubectl delete pod node-0
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3. SPLIT-BRAIN: if io_wait > 0.80 → kubectl throttle ingress --rate=0.5
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4. HOT-SHARD: if one worker cpu > 0.90, others low → reroute traffic
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5. RETRY STORM: if p99 > 100ms and rr > 150 → kubectl throttle ingress --rate=0.4
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6. ZOMBIE NODE: if worker cpu near 0 → reroute away from it
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7. BLACK SWAN: if 2+ nodes failed (DB alive) → kubectl throttle ingress --rate=0.3
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8. DB STRESS: if node-0 cpu > 0.80 → kubectl throttle ingress --rate=0.7
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9. SAFE SCALE: if avg worker cpu > 0.75 and budget > 20 → scale up
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10. HEALTHY → no_op
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Output format:
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<reasoning>One sentence identifying which rule applies.</reasoning>
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<action>{"command": "kubectl ..."}</action>"""
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obs = {
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"cpu_loads": [0.45, 0.82, 0.79, 0.88, 0.75, 0.81, 0.77, 0.73],
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"mem_utilizations": [0.41, 0.68, 0.71, 0.65, 0.62, 0.70, 0.66, 0.64],
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"queue_lengths": [12, 45, 41, 53, 38, 44, 40, 37],
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"failed_nodes": [],
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"latency_ms": 187.3,
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"p99_latency": 312.5,
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"request_rate": 1840.0,
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"io_wait": 0.12,
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"error_budget": 85,
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"step": 4,
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"task_hint": "System is under heavy traffic load."
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}
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import json
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messages = [
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{"role": "system", "content": system_prompt},
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{"role": "user", "content": f"Current system state:\n{json.dumps(obs, indent=2)}\nWhat action should be taken?"}
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]
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text = tokenizer.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
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inputs = tokenizer(text, return_tensors="pt").to(model.device)
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outputs = model.generate(
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**inputs,
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max_new_tokens=1024,
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temperature=0.6,
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top_p=0.95,
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do_sample=True,
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)
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print(tokenizer.decode(outputs[0][inputs["input_ids"].shape[1]:], skip_special_tokens=True))
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```
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Expected output:
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```
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<think>
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P99 latency is 312ms with request rate 1840 rps and no failed nodes.
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Rule 5 (retry storm): p99 > 100ms and rr > 150 → throttle at 0.4.
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</think>
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<reasoning>Rule 5 applies: p99 latency 312ms exceeds threshold with high request rate 1840 rps — throttle ingress to shed load.</reasoning>
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<action>{"command": "kubectl throttle ingress --rate=0.4"}</action>
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```
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---
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## Training Details
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| Parameter | Value |
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| Base model | `Qwen/Qwen3-8B` (BF16) |
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| Method | GRPO (TRL 0.24.0 + Unsloth + vLLM 0.6.3) |
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| LoRA rank | 32, alpha=64, all projection layers |
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| Trainable params | 1.05% (349 MB adapter) |
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| Training steps | 300 |
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| Batch size | 1 × 4 generations = 4 completions/step |
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| Learning rate | 5e-6, cosine schedule |
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| Max completion length | 1024 tokens |
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| GPU | A100-SXM4-80GB |
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| Wall-clock time | 44 minutes |
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---
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## Citation
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```bibtex
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@misc{dime2026,
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title = {Fine-Tuning Language Models as Autonomous SREs via GRPO: The DIME Benchmark},
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author = {Nithish Sriram and Naseer},
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year = {2026},
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url = {https://huggingface.co/Naseer-010/Qwen3-8B-Finetuned-DIME}
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}
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```
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---
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*Trained at SRM AP · Hackathon 2026*
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