NLP Pipeline Builder

---
name: NLP Pipeline Builder
slug: nlp-pipeline-builder
description: Build natural language processing pipelines for text analysis and understanding
category: ai-ml
complexity: intermediate
version: "1.0.0"
author: "ID8Labs"
triggers:
  - "build NLP pipeline"
  - "text processing"
  - "NLP workflow"
  - "language processing"
  - "text analysis"
tags:
  - NLP
  - text-processing
  - pipeline
  - language
  - analysis
---

# NLP Pipeline Builder

The NLP Pipeline Builder skill guides you through designing and implementing natural language processing pipelines that transform raw text into structured, actionable insights. From preprocessing to advanced analysis, this skill covers the full spectrum of NLP tasks and helps you choose the right approach for your specific needs.

Modern NLP offers multiple paradigms: rule-based approaches, classical ML, and deep learning/LLMs. This skill helps you navigate these options, building pipelines that balance accuracy, latency, cost, and maintainability. Whether you need real-time processing at scale or deep analysis of specific documents, this skill ensures your pipeline is fit for purpose.

From tokenization to semantic analysis, from single documents to streaming text, this skill helps you build robust NLP systems that handle real-world text with all its messiness and complexity.

## Core Workflows

### Workflow 1: Design NLP Pipeline Architecture
1. **Define** requirements:
   - Input: What text? What format? What volume?
   - Output: What information to extract?
   - Constraints: Latency, accuracy, cost
2. **Select** pipeline stages:
   ```
   Standard NLP Pipeline:
   Text → Preprocessing → Tokenization → Feature Extraction → Task Model → Output

   Example stages:
   - Preprocessing: cleaning, normalization
   - Linguistic: tokenization, POS, NER, parsing
   - Semantic: embeddings, topic modeling
   - Task-specific: classification, extraction, generation
   ```
3. **Choose** approach per stage:
   | Stage | Classical | Deep Learning | LLM |
   |-------|-----------|---------------|-----|
   | Tokenization | Regex, NLTK | SentencePiece | Model-specific |
   | NER | CRF, rules | BiLSTM-CRF, BERT | Prompt-based |
   | Classification | SVM, NB | CNN, BERT | Zero/few-shot |
   | Extraction | Regex, patterns | Seq2Seq | Prompt-based |
4. **Design** error handling and fallbacks
5. **Document** architecture

### Workflow 2: Implement Text Preprocessing
1. **Clean** text:
   ```python
   def clean_text(text):
       # Normalize unicode
       text = unicodedata.normalize("NFKC", text)

       # Remove or replace problematic characters
       text = remove_control_characters(text)

       # Normalize whitespace
       text = " ".join(text.split())

       # Optionally: lowercase, remove punctuation, etc.
       # (depends on downstream tasks)

       return text
   ```
2. **Segment** into units:
   - Sentence splitting
   - Paragraph detection
   - Document structuring
3. **Tokenize** appropriately:
   - Word tokenization for analysis
   - Subword tokenization for models
   - Language-specific considerations
4. **Normalize** for consistency:
   - Case normalization
   - Lemmatization/stemming
   - Handling contractions, abbreviations

### Workflow 3: Build Production NLP System
1. **Set up** processing infrastructure:
   ```python
   class NLPPipeline:
       def __init__(self, config):
           self.preprocessor = TextPreprocessor(config)
           self.tokenizer = load_tokenizer(config.tokenizer)
           self.models = {
               "ner": load_model(config.ner_model),
               "sentiment": load_model(config.sentiment_model),
               "classification": load_model(config.classifier)
           }
           self.cache = ResultCache() if config.use_cache else None

       def process(self, text, tasks=None):
           tasks = tasks or ["all"]

           # Preprocessing
           cleaned = self.preprocessor.clean(text)
           tokens = self.tokenizer.tokenize(cleaned)

           # Run requested analyses
           results = {"text": text, "tokens": tokens}
           for task, model in self.models.items():
               if task in tasks or "all" in tasks:
                   results[task] = model.predict(tokens)

           return results
   ```
2. **Implement** batching for throughput
3. **Add** caching for repeated inputs
4. **Set up** monitoring and logging
5. **Test** with diverse inputs

## Quick Reference

| Action | Command/Trigger |
|--------|-----------------|
| Design pipeline | "Design NLP pipeline for [task]" |
| Preprocess text | "How to preprocess [text type]" |
| Choose tokenizer | "Best tokenizer for [use case]" |
| Extract entities | "Extract entities from text" |
| Classify text | "Build text classifier" |
| Scale pipeline | "Scale NLP to [volume]" |

## Best Practices

- **Understand Your Text**: Different text requires different treatment
  - Social media: informal, abbreviations, emoji
  - Legal/medical: domain terms, structure
  - Multilingual: language detection, appropriate tools

- **Preserve What Matters**: Preprocessing shouldn't destroy information
  - Don't lowercase if case is meaningful
  - Keep punctuation if it affects meaning
  - Document all transformations

- **Handle Encoding Correctly**: Unicode is tricky
  - Always normalize (NFKC recommended)
  - Handle encoding errors gracefully
  - Test with diverse scripts and characters

- **Batch for Efficiency**: Model inference is expensive
  - Batch inputs for GPU utilization
  - Balance batch size vs latency
  - Use async processing where appropriate

- **Fail Gracefully**: Text is messy and unpredictable
  - Handle empty, too-long, or malformed inputs
  - Provide sensible defaults for edge cases
  - Log failures for analysis

- **Version Your Pipeline**: Reproducibility matters
  - Pin model versions
  - Document preprocessing steps
  - Track configuration changes

## Advanced Techniques

### Multi-Stage Extraction Pipeline
Chain extractors for complex information:
```python
class ExtractionPipeline:
    def __init__(self):
        self.ner = NERModel()
        self.relation = RelationExtractor()
        self.coreference = CoreferenceResolver()

    def extract(self, text):
        # Stage 1: Named Entity Recognition
        entities = self.ner.extract(text)

        # Stage 2: Coreference Resolution
        resolved = self.coreference.resolve(text, entities)

        # Stage 3: Relation Extraction
        relations = self.relation.extract(text, resolved)

        # Stage 4: Build knowledge graph
        graph = build_graph(resolved, relations)

        return {
            "entities": resolved,
            "relations": relations,
            "graph": graph
        }
```

### Hybrid Classical + LLM Pipeline
Use LLMs where they add value, classical where they don't:
```python
class HybridPipeline:
    def process(self, text):
        # Fast classical preprocessing
        cleaned = classical_clean(text)
        sentences = classical_sentence_split(cleaned)

        # Classical NER (fast, predictable)
        entities = classical_ner(sentences)

        # LLM for complex tasks (slower, more capable)
        sentiment = llm_sentiment(text)  # Nuanced sentiment
        summary = llm_summarize(text)    # Abstractive summary

        return {
            "sentences": sentences,
            "entities": entities,  # Classical
            "sentiment": sentiment,  # LLM
            "summary": summary  # LLM
        }
```

### Streaming Text Processing
Handle continuous text streams:
```python
class StreamingNLP:
    def __init__(self, batch_size=32, timeout_ms=100):
        self.batch_size = batch_size
        self.timeout_ms = timeout_ms
        self.buffer = []
        self.last_process_time = time.time()

    async def add(self, text):
        self.buffer.append(text)

        # Process if batch full or timeout
        if len(self.buffer) >= self.batch_size:
            return await self.flush()
        elif (time.time() - self.last_process_time) * 1000 > self.timeout_ms:
            return await self.flush()

    async def flush(self):
        if not self.buffer:
            return []

        batch = self.buffer
        self.buffer = []
        self.last_process_time = time.time()

        # Batch process
        results = await self.pipeline.process_batch(batch)
        return results
```

### Language Detection and Routing
Handle multilingual text:
```python
class MultilingualPipeline:
    def __init__(self):
        self.detector = LanguageDetector()
        self.pipelines = {
            "en": EnglishPipeline(),
            "es": SpanishPipeline(),
            "zh": ChinesePipeline(),
            "default": UniversalPipeline()
        }

    def process(self, text):
        lang = self.detector.detect(text)
        pipeline = self.pipelines.get(lang, self.pipelines["default"])

        return {
            "language": lang,
            "results": pipeline.process(text)
        }
```

## Common Pitfalls to Avoid

- Over-preprocessing and destroying meaningful information
- Ignoring Unicode normalization and encoding issues
- Using word tokenizers for languages without spaces
- Not handling edge cases (empty text, very long text)
- Assuming English-only when users may send other languages
- Running expensive models on every input when caching would help
- Not batching model inference for throughput
- Ignoring the latency impact of pipeline stages