apna

Senior Data Scientist / Research Scientist - LLM Training & Fine-tuning

apna  •  Bengaluru, IN (Onsite)  •  3 months ago
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Job Description

Job Title
Senior Data Scientist / Research Scientist — LLM Training & Fine-tuning (Indian Languages, Tool Calling, Speed)
Location: Bangalore

About the Role

We’re looking for a hands-on Data Scientist / Research Scientist who can fine-tune and train open-source LLMs end-to-end—not just run LoRA scripts. You’ll own model improvement for Indian languages + code-switching (Hinglish, etc.), instruction following, and reliable tool/function calling, with a strong focus on latency, throughput, and production deployability
This is a builder role: you’ll take models from research → experiments → evals → production.

What You’ll Do (Responsibilities)


Train and fine-tune open LLMs (continued pretraining, SFT, preference optimization like DPO/IPO/ORPO, reward modeling if needed) for:
Indian languages + multilingual / code-switching
Strong instruction following
Reliable tool/function calling (structured JSON, function schemas, deterministic outputs)
• Build data pipelines for high-quality training corpora:
Instruction datasets, tool-call traces, multilingual data, synthetic data generation
De-duplication, contamination control, quality filtering, safety filtering
• Develop evaluation frameworks and dashboards:
Offline + online evals, regression testing
Tool-calling accuracy, format validity, multilingual benchmarks, latency/cost metrics
• Optimize models for speed and serving
Quantization (AWQ/GPTQ/bnb), distillation, speculative decoding, KV-cache optimizations
Serve via vLLM/TGI/TensorRT-LLM/ONNX where appropriate
• Improve alignment and reliability
Reduce hallucinations, improve refusal behavior, enforce structured outputs
Prompting + training strategies for robust compliance and guardrails
• Collaborate with engineering to ship:
Model packaging, CI for evals, A/B testing, monitoring drift and quality
• Contribute research:
Read papers, propose experiments, publish internal notes, and turn ideas into measurable gains

What We’re Looking For (Qualifications)

Must-Have

4 - 6 years in ML/DS, with direct LLM training/fine-tuning experience
• Demonstrated ability to run end-to-end model improvement
data → training → eval → deployment constraints → iteration
• Strong practical knowledge of:
Transformers, tokenization, multilingual modeling
Fine-tuning methods LoRA/QLoRA, full fine-tune, continued pretraining
Alignment SFT, DPO/IPO/ORPO (and when to use what)
• Experience building or improving tool/function calling and structured output reliability
• Strong coding skills in Python, deep familiarity with PyTorch
• Comfortable with distributed training and GPU stacks:
DeepSpeed / FSDP, Accelerate, multi-GPU/multi-node workflows
• Solid ML fundamentals: optimization, regularization, scaling laws intuition, error analysis

Nice-to-Have

• Research background: MS/PhD or publications / strong applied research track record
• Experience with Indian language NLP
Indic scripts, transliteration, normalization, code-mixing, ASR/TTS text quirks
• Experience with pretraining from scratch or large-scale continued pretraining
• Practical knowledge of serving
vLLM / TGI / TensorRT-LLM, quantization + calibration, profiling
• Experience with data governance: privacy, PII redaction, dataset documentation
Tech Stack (Typical)

  • PyTorch, Hugging Face Transformers/Datasets, Accelerate
  • DeepSpeed / FSDP, PEFT (LoRA/QLoRA)
  • Weights & Biases / MLflow
  • vLLM / TGI / TensorRT-LLM
  • Ray / Airflow / Spark (optional), Docker/Kubernetes
  • Vector DB / RAG stack familiarity is a plus


What Success Looks Like (90–180 Days)

• Ship a fine-tuned open model that measurably improves:
Instruction following and tool calling correctness
Indic language performance + code-switching robustness
Lower latency / higher throughput at equal quality
• Stand up a repeatable pipeline:
dataset versioning, training recipes, eval harness, regression gates
• Build a roadmap for next upgrades (distillation, preference tuning, multilingual expansion)

Interview Process

  • 30-min intro + role fit
  • Technical deep dive: prior LLM work (training/evals/production constraints)
  • Take-home or live exercise: design an LLM fine-tuning + eval plan for tool calling + Indic language
  • Systems round: training/serving tradeoffs, cost/latency, failure modes
  • Culture + collaboration round
apna

About apna

Founded in 2019, Apna Group is redefining the future of work for India and beyond - empowering millions of professionals and enterprises through AI-led innovation.

Through Apna.co, India’s largest early-career job marketplace, we’ve connected 6 Cr+ job seekers with 7 Lakh+ employers across 900+ cities, enabling faster, smarter, and more meaningful hiring at scale.

Trusted by India’s leading enterprises such as Teleperformance, Zomato, HDB Financial Services, Bluestar, TVS, Kotak, Axis Bank, Flipkart, and Lifestyle, Apna powers workforce transformation across Retail, BFSI, Staffing, Healthcare, Manufacturing, and IT sectors.

Building on this foundation, Apna has expanded into enterprise AI innovation with Blue Machines, our Voice AI platform that enables organizations to deploy production-grade voice agents with sub-300 ms latency and <1-week deployment cycles. In its first 45 days, Blue Machines secured $6 M+ in enterprise contracts across lending, insurance, recruitment, and healthcare - making it one of India’s fastest-adopted deep-tech platforms.

Explore more at bluemachines.ai

Recognized among India’s Most Preferred Workplaces 2025–26, and as a Most Preferred Workplace for Women, Apna Group continues to build technology that empowers people, strengthens enterprises, and drives inclusive growth.

Backed by world-class investors including Tiger Global, Sequoia Capital, Lightspeed, Insight Partners, GSV Ventures, and Owl Ventures, Apna collaborates with leading government and public institutions such as the NSDC, Ministry of Defence, UNICEF YuWaah, and AICTE to drive nationwide skilling and employability programs - powering AICTE’s career portal for over 3 million students across 22,000 colleges.

Visit: apna.co

For employer solutions, visit: employer.apna.co

Industry
IT & Software
Company Size
1,001-5,000 employees
Headquarters
Bengaluru, IN
Year Founded
2019
Website
apna.co
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