DevCalc guides

Technical decisions, explained clearly.

Practical references for using developer utilities safely and planning AI systems with realistic assumptions.

AI infrastructure

How Much VRAM Does an LLM Need?

A practical breakdown of model weights, KV cache, context length, batching, and runtime overhead.

8 min readRead guide
AI infrastructure

LLM Quantization: FP16, INT8, and INT4 Explained

Understand what lower precision changes, what it saves, and why file size is not the whole deployment story.

7 min readRead guide
AI budgeting

How to Calculate AI API Costs

Forecast spend using input tokens, output tokens, cache rates, request volume, and realistic usage distributions.

8 min readRead guide
Developer workflow

JSON Formatting and Validation Without Exposing Data

Diagnose malformed JSON safely and understand the errors formatters are helping you find.

6 min readRead guide
Security

How to Decode a JWT Safely

Read JWT claims without confusing decoding with signature verification or trust.

7 min readRead guide
Developer workflow

A Practical Guide to Cron Expressions

Read five-field schedules, avoid timezone surprises, and test jobs before they reach production.

6 min readRead guide
AI infrastructure

How to Calculate KV Cache Memory

Understand the variables behind one of the largest memory costs in long-context LLM inference.

7 min readRead guide
AI infrastructure

Choosing a GPU for Local LLMs

Balance memory capacity, bandwidth, runtime compatibility, power, and workload requirements.

8 min readRead guide
AI infrastructure

INT4 vs INT8 for LLM Inference

Compare memory savings, output quality, performance, and operational compatibility.

7 min readRead guide
AI budgeting

How Token Caching Reduces API Costs

Estimate cache-eligible input, hit rates, invalidation, and the real effect on model spending.

7 min readRead guide
Developer workflow

Unix Seconds vs Milliseconds

Recognize timestamp units, prevent 1970 dates, and exchange time safely between systems.

6 min readRead guide
Developer workflow

Common JSON Validation Errors

Find trailing commas, invalid quotes, escaping problems, and structural mistakes faster.

6 min readRead guide