AI Engineer 2 · Feed Ranking & Trust, Meesho

Ranking models that answer in 20 ms.

I build the models that decide what 100M+ shoppers see, and the ones that decide which orders to trust. Four years of production ranking, mostly spent on the same three problems at higher throughput: conflicting objectives, learning from what users didn’t click, and inference budgets measured in milliseconds. Currently pulling that experience toward LLM post-training and alignment.

Publication
AAAI 2026
Checkout risk scoring
400 → 20 ms
Home-feed ranker
+5 pp NDCG@50
In production since
2022

Shipped, and still running

Four systems I own or built at Meesho. Each one is live on the platform today.

Home-feed ranking

Multi-task ranker for a cold-start-heavy feed

A CGC/PLE architecture over a shared FT-Transformer encoder, predicting pCTR, pCTCVR and conditional pCVR inside a strict serving budget. Rebuilt it for near-cold users with soft negatives, a learned gate that suppresses items resembling past skips, and an ESMM-style CTunCVR task over the unclicked space.

+5 pp NDCG@50 on orders

Trust & risk · AAAI 2026

Return-to-origin risk, scored at checkout

A transformer over transaction sequences, behavioural features and graph embeddings, predicting delivery refusal. Compiling the serving path with TensorRT is what made it synchronous: 400 ms of inference does not fit in a checkout call, 20 ms does. Now scores every order placed on Meesho.

−2% platform RTO +1.6% NMV 20 ms p50

Catalogue understanding

Product similarity as an attribute oracle

Supplier-declared catalogue data is unreliable, so I stopped trusting it. FLAVA embeddings, hierarchically clustered and FAISS-indexed, impute shipping weight, fabric and taxonomy fields from matched products instead; Gemini fills the residual long tail. Platform-wide.

weight accuracy 60% → 83% −₹5.3 median shipping / catalogue 500 sub-categories

Abuse detection

Session embeddings that surface collusion

Self-supervised representations of user sessions, learned without labels, that separate supplier collusion and scripted bot traffic from ordinary browsing. At a 0.5% session flag rate it holds 81% precision against manual review, and recovers 2.3× the fraudulent GMV the previous rules engine caught. Now a standing feature in Meesho’s trust and risk model.

81% precision @ 0.5% flag rate 2.3× fraudulent GMV recovered

Research

AAAI 2026 · co-author

TRUST: Transaction Risk via Unified Sequence and Topology

Meesho Data Science team, Proceedings of the 40th AAAI Conference on Artificial Intelligence. Unifies a transformer over transaction sequences with topological signal from a buyer–seller interaction graph to score delivery-refusal risk, and shows the two views are complementary rather than redundant. Deployed platform-wide.

M.Tech. thesis · IIT Delhi, 2022

Consistent and Uncertainty-Driven SLAM

Advised by Prof. Chetan Arora. Treats per-pixel depth uncertainty as a first-class input to pseudo-RGBD SLAM rather than a post-hoc confidence score, with a temporal-consistency objective so predicted depth agrees across a video sequence. Backpropagating an ORB-SLAM trajectory signal through gradSLAM trains the depth model with no ground truth at all — 15% lower Absolute Trajectory Error in five epochs, beating the D3VO, gradSLAM and DROID-SLAM baselines it was layered onto on both trajectory accuracy and reconstruction density.

Where I’ve worked

Full detail, dates and numbers are in the CV.

Apr 2024 — Present

Bengaluru

Meesho

AI Engineer 2 — Feed Ranking & Trust

  • Own the home-feed multi-task ranker and its cold-start rebuild. +5 pp NDCG@50 on orders.
  • Built the RTO risk model published as TRUST, and got it to 20 ms so it could run synchronously at checkout.
  • Built the platform-wide product-similarity model behind catalogue attribute imputation. +1.4% NMV.
  • Self-supervised session embeddings for collusion and bot detection, now a standing trust-model feature.
  • Mentor two junior data scientists on the multimodal team — scoping, model review, and setting the evaluation bar before anything reaches an online experiment.

Jul 2022 — Mar 2024

Bengaluru

Amazon

SDE — Central Machine Learning

  • Led LLM4AMZN: adapted generalist instruction-tuned LLMs to Amazon-domain corpora (AmaFLAN) through continued pre-training and instruction tuning, beating FLAN baselines on accuracy and PR-AUC across zero- and few-shot catalogue tasks.
  • Tuned LoRA rank, adapter placement and schedule to match baseline quality at faster convergence, then ran the model as a pseudo-labeller over cold-start categories — ~30% less annotation demand.
  • Built the surrounding data and serving infrastructure: ingestion through AWS Comprehend, DynamoDB and a governed data lake, plus ECS Fargate orchestration pushing 22,000+ daily Q&A updates into Kendra behind Amazon’s Live Assistant.
  • Recalibrated per-attribute Elasticsearch ranking weights on a recurring schedule with a learning-to-rank model over the same features. +10% internal search NDCG.

Feb — May 2021

Remote

Amazon

Applied Scientist Intern — Search by Data

  • Automatic feature selection for catalogue datasets with 100+ attributes: recommends the top-k attributes maximising downstream PR-AUC/ROC-AUC, replacing both hand-picked feature sets and the brute-force cost of training over everything available.
  • Vowpal Wabbit for fast training over high-cardinality text and categorical features, and for interpretable importance ranking of what it selected.

Jun — Jul 2021

Gurugram

Freecharge (Axis Bank)

SDE Intern

  • A filesystem abstraction over S3 — list, delete and pre-signed URL issuance behind one API — so two Axis Bank services could manage stored assets without proxying object bytes through application servers. Path and access-metadata caching in MongoDB served 25K requests/day at 20% lower server load.

2017 — 2022

New Delhi

Indian Institute of Technology Delhi

Dual Degree (B.Tech. + M.Tech.), Computer Science

  • M.Tech. CPI 9.67/10. Machine Learning, Computer Vision, AI, Information Retrieval, Parallel & Distributed Programming, Probability & Stochastic Processes.
  • Teaching assistant for Introduction to Machine Learning (Prof. Rahul Garg) — authored and graded the assignments as Kaggle competitions, ran the weekly doubt sessions.
  • Technical Coordinator, Rendezvous — led backend for the festival site, supervised 12 activity heads, shipped auth, admin and sponsor portals on AWS.

What I reach for

Post-training

Supervised fine-tuning, reward modelling, preference optimisation (DPO, GRPO), LoRA and other parameter-efficient adaptation, domain-adaptive continued pre-training, pseudo-labelling and distillation, instruction-tuned model evaluation.

Ranking & retrieval

Learning-to-rank. Multi-task learning (CGC/PLE, gradient balancing). CTR/CVR/CTCVR modelling in the ESMM family. Negative-signal and implicit-feedback modelling. Embedding retrieval. Exposure and position debiasing (IPW/IPS, PAL, ESCM²). Multimodal and sequential representations.

Inference & training systems

Low-latency serving under hard SLAs. TensorRT and ONNX graph optimisation. Mixed-precision numerics (FP32/BF16/FP8). Distributed training with PyTorch DDP and AMP. Throughput and tail-latency profiling, batching policy, precision calibration.

Languages

Python, C++, Java, SQL, Scala (PySpark / Spark SQL).

Tooling

PyTorch, Hugging Face Transformers / PEFT / TRL, scikit-learn, NumPy, Detectron2, Vowpal Wabbit. PySpark on Databricks (GCP), MLflow, Docker, Git.

Infrastructure

AWS — EC2, ECS Fargate, S3, DynamoDB, Kendra, Comprehend. Linux and the usual shell tooling.

Get in touch

Happy to talk about ranking, post-training, or getting a model under budget.